This document discusses various metrics used to measure the efficiency of air conditioning systems, including COP, EER, SEER, and HSPF. It explains that COP, EER, SEER, and HSPF measure the ratio of cooling/heating output to power input, with higher numbers indicating greater efficiency. The document provides equations to convert between these metrics and discusses minimum efficiency standards set by the US Department of Energy.
This document discusses fundamentals of air distribution systems including duct materials, shapes, sizing methods, and design considerations. It covers topics such as duct pressure classifications, sealing requirements, outlet selection factors, and fan sizing calculations. The key points are that ducts distribute air through a building, duct materials include galvanized iron and aluminum, and fan selection involves calculating pressure drops through ducts, dampers, and terminals to determine required static pressure.
HVAC systems control temperature, humidity, air flow, and air filtration to condition air. The document discusses the basics of HVAC including major components like compressors, condensers, evaporators and expansion valves. Different types of HVAC systems are described for various applications from residential to industrial. Factors that influence system selection and sizing include budget, space constraints, climate and load calculations. Ventilation and its importance for indoor air quality is also covered.
Heating Ventilation & Air Conditioning (HVAC)Joshua Joel
The document provides an overview of HVAC (heating, ventilation, and air conditioning) systems. It discusses key components such as furnaces, heat exchangers, evaporator coils, condensing units, ducts, vents, and thermostats. It explains how HVAC systems work to moderate interior temperatures through heating in winter and cooling in summer. Performance metrics for HVAC systems like efficiency, EER, and SEER are also defined.
This document provides information on ventilation and air conditioning systems for buildings. It discusses the importance of ventilation to remove stale air and introduce fresh air. Natural ventilation relies on wind and stack effects, while mechanical ventilation uses fans. Central air conditioning systems condition air at a central plant and distribute via ducts, while split systems have indoor and outdoor components. Proper selection of heating, cooling, and ventilation equipment requires balancing multiple factors like energy efficiency and indoor air quality.
A lecture in the process of changing or replacing air in any space to provide high indoor air quality (i.e. to control temperature, replenish oxygen, or remove moisture, odors, smoke, heat, dust, airborne bacteria, and carbon dioxide).
Complete hvac ppt by kk 354647.pptx 1234KRISHAN KUMAR
This document provides an overview of heating, ventilation, and air conditioning (HVAC) systems. It discusses the history and development of HVAC, including early innovations in refrigeration. The core components and functions of HVAC systems are described, such as furnaces, ducts, air conditioners, and heat pumps. Various types of HVAC installations and systems are covered, like central air, zoned heating, and radiant heat. Recent developments in HVAC technology and applications are also summarized along with the advantages and disadvantages of HVAC.
This document discusses duct design and air distribution for air conditioning systems. It describes the key components of an air distribution system including supply and return air ducts and outlets. It classifies ducts as either high or low velocity and notes that low velocity ducts using rectangular shapes are most common. The document discusses factors that influence duct design like aspect ratio, pressure losses, and different duct sizing methods such as velocity reduction, equal friction loss, and static pressure recovery. It concludes with descriptions of air outlets and their typical locations in a room.
Ventilation is the process of changing or replacing air in an indoor space to provide good indoor air quality. There are two main types of ventilation: natural ventilation which uses wind and stack effects, and mechanical ventilation which uses fans or other mechanical means. Natural ventilation has advantages of being simple and requiring no power, while mechanical ventilation can ensure consistent air changes and filter air. Proper ventilation is important for removing odors, carbon dioxide, heat, and other pollutants from indoor spaces.
This document discusses fundamentals of air distribution systems including duct materials, shapes, sizing methods, and design considerations. It covers topics such as duct pressure classifications, sealing requirements, outlet selection factors, and fan sizing calculations. The key points are that ducts distribute air through a building, duct materials include galvanized iron and aluminum, and fan selection involves calculating pressure drops through ducts, dampers, and terminals to determine required static pressure.
HVAC systems control temperature, humidity, air flow, and air filtration to condition air. The document discusses the basics of HVAC including major components like compressors, condensers, evaporators and expansion valves. Different types of HVAC systems are described for various applications from residential to industrial. Factors that influence system selection and sizing include budget, space constraints, climate and load calculations. Ventilation and its importance for indoor air quality is also covered.
Heating Ventilation & Air Conditioning (HVAC)Joshua Joel
The document provides an overview of HVAC (heating, ventilation, and air conditioning) systems. It discusses key components such as furnaces, heat exchangers, evaporator coils, condensing units, ducts, vents, and thermostats. It explains how HVAC systems work to moderate interior temperatures through heating in winter and cooling in summer. Performance metrics for HVAC systems like efficiency, EER, and SEER are also defined.
This document provides information on ventilation and air conditioning systems for buildings. It discusses the importance of ventilation to remove stale air and introduce fresh air. Natural ventilation relies on wind and stack effects, while mechanical ventilation uses fans. Central air conditioning systems condition air at a central plant and distribute via ducts, while split systems have indoor and outdoor components. Proper selection of heating, cooling, and ventilation equipment requires balancing multiple factors like energy efficiency and indoor air quality.
A lecture in the process of changing or replacing air in any space to provide high indoor air quality (i.e. to control temperature, replenish oxygen, or remove moisture, odors, smoke, heat, dust, airborne bacteria, and carbon dioxide).
Complete hvac ppt by kk 354647.pptx 1234KRISHAN KUMAR
This document provides an overview of heating, ventilation, and air conditioning (HVAC) systems. It discusses the history and development of HVAC, including early innovations in refrigeration. The core components and functions of HVAC systems are described, such as furnaces, ducts, air conditioners, and heat pumps. Various types of HVAC installations and systems are covered, like central air, zoned heating, and radiant heat. Recent developments in HVAC technology and applications are also summarized along with the advantages and disadvantages of HVAC.
This document discusses duct design and air distribution for air conditioning systems. It describes the key components of an air distribution system including supply and return air ducts and outlets. It classifies ducts as either high or low velocity and notes that low velocity ducts using rectangular shapes are most common. The document discusses factors that influence duct design like aspect ratio, pressure losses, and different duct sizing methods such as velocity reduction, equal friction loss, and static pressure recovery. It concludes with descriptions of air outlets and their typical locations in a room.
Ventilation is the process of changing or replacing air in an indoor space to provide good indoor air quality. There are two main types of ventilation: natural ventilation which uses wind and stack effects, and mechanical ventilation which uses fans or other mechanical means. Natural ventilation has advantages of being simple and requiring no power, while mechanical ventilation can ensure consistent air changes and filter air. Proper ventilation is important for removing odors, carbon dioxide, heat, and other pollutants from indoor spaces.
Recuperators are heat exchangers that transfer heat from one fluid stream to another without mixing the fluids. They are commonly used to recover waste heat from exhaust gases to preheat intake air in applications like gas turbines, furnaces, and ventilation systems. This increases efficiency by reducing the amount of fuel or additional heat needed. Recuperators transfer heat through a solid barrier separating the fluid streams and come in designs like plate, tube, or rotary. They provide efficiency gains over alternatives but require maintenance to address deposits on heat transfer surfaces over time.
This document is a presentation about climate and building design given by Dr. Mark Jentsch at a workshop in Oman. It discusses how climate impacts building design and how vernacular architecture has traditionally adapted to local climates. However, modern architecture often ignores climatic considerations. It also addresses how the climate is changing globally due to factors like greenhouse gas emissions, and the need to adapt building design to future climate conditions.
The document discusses kitchen ventilation design and calculations. It explains that an effective kitchen ventilation design requires determining the cubic feet of the kitchen area, calculating additional airflow needed based on appliance size and fuel type, and designing the duct run while accounting for equivalent duct length. Key factors that influence the design include hood location and coverage, appliance recommendations, ceiling height, duct length and turns, and whether makeup air is required.
HVAC systems are designed to heat, cool, and ventilate indoor spaces for human comfort. Heating increases temperature while cooling decreases it. Ventilation maintains indoor air quality through exhaust and fresh air. Air conditioning alters temperature, humidity, and air quality. Common HVAC systems include window units for single rooms, split units with indoor and outdoor components, packaged units for medium loads, and central air for large buildings. Vapor compression is the most widely used refrigeration cycle, involving an evaporator, compressor, condenser, and expansion valve.
Design of air conditioning and ventilation system for a multi storey office b...eSAT Journals
Abstract This project consists of how the proposed centralized air conditioning and mechanical ventilation system is designed and its criterion for a new building in Hyderabad. It consists of seven floors and two basements having an area of 39000sft per floor. The two basement (lower and upper) and major part of ground floor shall be meant for offices with a total area of 273000sft. The main objective is to create a thermally controlled environment within the space of a building envelope such as office space, BMS room, society room, entrance lobby etc. and building mechanical ventilation namely basement ventilation, staircase pressurisation, lift well pressurisation, toilet exhaust etc. Design and planning of the above system shall meet the required below customer objectives, like econoical in cost,energy efficient,simple and flexible with respect to operation and maintenance. The tentative air conditioning load for the system shall be 800TR apprix. Air cooled screw chillers with secondary variable pumping system are proposed to make the system energy efficient. The proposed air conditioning plant shall be located on the sw side on the building terrace. keywords: chillers, variable air volume, air handling unit
The document discusses the history and scientific development of cooling tower design theory. It begins by explaining how Merkel developed the first scientific theory for evaluating cooling tower performance in 1925. It then provides definitions of key cooling tower concepts like approach, range, and heat transfer methods. The document goes on to describe parameters like tower characteristics, fan power requirements, and water loss factors. It also summarizes Merkel's assumptions and the development of generalized supply equations from manufacturer curves.
This document discusses different types of HVAC systems and their applications. It provides information on direct expansion systems versus chilled water systems, package units, split units, air handling units, fan coil units, and chilled water systems. Specific HVAC system considerations and requirements are discussed for different building types like hospitals, hotels, and frozen food storage facilities. Key factors in HVAC system selection include temperature and humidity control, air movement and distribution, filtration, and achieving proper indoor environmental conditions for the building type and use.
An integrated gasification combined cycle (IGCC) power plant converts coal into synthesis gas (syngas) through gasification. The syngas is then cleaned before fueling a combustion turbine to generate electricity. Exhaust heat from the turbine produces steam to drive a steam turbine. This combined cycle configuration achieves high efficiencies. The IGCC plant includes components for coal preparation, gasification, syngas cooling/cleaning, and syngas use in the combustion turbine. Benefits include high efficiency and easier carbon capture, while drawbacks are higher costs and more complex operation than conventional coal plants. Existing IGCC plants are located in the United States but none currently in India.
The presentation discusses the various factors which affect the performance of Power Boilers including the quality of coal, airheater performance, air ingress etc.
The document provides information about a group assignment for a central air conditioning system. It includes definitions of air conditioning and central air conditioning systems. It describes the typical components of a central AC system such as the compressor, air handling unit, return air inlets, cool air dispenser, condenser, and cooling tower. It provides a case study of a water-cooled condenser and explains the cooling process within the condenser and cooling tower. Common problems, maintenance requirements, and advantages/disadvantages of central AC systems are also summarized.
This document discusses various types of equipment that can be used to recover waste heat, including recuperators, regenerators, heat wheels, heat pipes, economizers, shell and tube heat exchangers, plate heat exchangers, and run around coil exchangers. It provides details on the design and operation of each type of equipment and examples of common industrial applications where they are used, such as recovering heat from boiler flue gases, furnaces, dryers, and other processes to improve energy efficiency.
The document provides details about the HVAC and fire protection systems at Subang Parade mall in Malaysia. It discusses the centralized HVAC system, which includes 70 air handling units, 3 cooling towers, and 2 chiller systems. It also describes the fire protection systems, including smoke detectors, sprinklers, fire alarms, and extinguishers. Issues with the existing systems like noise and lack of maintenance are identified. Recommendations are provided to improve the HVAC system with ice storage cooling and update the fire systems with water mist and improved detectors.
Shakil Hossain presented on cooling tower and cooling water circuits. The presentation covered different types of cooling systems including open, closed, and mixed systems. It described the components and types of cooling towers such as natural draught, forced draught, and induced draught towers. The presentation also discussed liquid cooling systems including liquid-to-liquid, closed-loop dry, open-loop evaporative, closed-loop evaporative, and chilled water systems. The key advantages and disadvantages of natural draught, forced draught, and induced draught cooling towers were highlighted.
Este documento describe los intercambiadores de calor plásticos, incluyendo sus ventajas sobre los intercambiadores metálicos, los materiales plásticos comúnmente utilizados y sus rangos de temperatura y presión, y los métodos de diseño y fabricación. Los intercambiadores de calor plásticos son adecuados para aplicaciones agresivas químicamente debido a la inercia química de los plásticos. Se diseñan con diámetros de tubería más pequeños para compensar la baja conductividad té
This document discusses natural draft cooling towers. It begins by defining a cooling tower as a device used to transfer heat and cool water for reuse. It then discusses the types of cooling towers, focusing on natural draft towers. The key components of a natural draft cooling tower are described, including the supply basin, cooling tower, fill material, and drift eliminators. The document explains that natural draft towers use the stack effect and heat transfer between warm water and ambient air to cool the water, which is then recirculated. Finally, it provides some strategies to improve the efficiency of natural draft cooling towers.
This document provides information on estimating hot water demand for plumbing systems. It discusses factors that influence hot water usage and provides estimates of usage for different household activities. Standard fixture units are presented as a method to estimate total hot water demand based on the type and number of fixtures. Flow rates are then estimated based on the total fixture unit count using probability curves.
This document discusses heating and cooling load calculations for buildings. It covers calculating heating loads by estimating transmission heat losses through walls, infiltration, and ductwork. Cooling load calculations are more complex as they consider time-varying outdoor conditions and internal heat gains. Methods for calculating cooling loads include using the Cooling Load Temperature Difference (CLTD) method for walls and roofs and considering solar heat gain factors for windows. The assumptions behind design cooling loads and calculating people loads are also outlined.
Applications of Refrigeration and Air Conditioning & RefrigerantsNITIN AHER
This document discusses refrigeration and air conditioning. It describes how refrigeration cools products or spaces below the surrounding temperature, while air conditioning controls temperature, moisture, cleanliness, odor, and air circulation for occupants or processes. Common applications are listed such as room air conditioners, refrigerators, evaporative coolers, and commercial refrigeration/air conditioning. The document then focuses on evaporative cooling systems, automotive air conditioners, refrigerants used, and criteria for selecting refrigerants including thermodynamic properties, environmental impact, and safety.
Design options for hvac distribution systemsJASON KEMBOI
This document discusses design options for HVAC distribution systems. It describes centralized HVAC systems which have four main components: an energy supply, service generators, distribution components like ducts, and delivery components like diffusers. The document focuses on air distribution design options, which include all-air, all-water, and air-water systems. All-air systems deliver heated or cooled air through ducts, all-water uses water and terminal units, and air-water uses a combination. The best design considers architectural, financial, and performance constraints.
The document discusses the coefficient of performance (COP) as it relates to heat pumps and refrigeration systems. It provides definitions and equations for calculating COP for both heating and cooling applications. Higher COP values indicate greater efficiency, with optimal performance dependent on factors like temperature differences and system design. Real-world COP is typically lower than theoretical maximums due to irreversible processes and other losses.
This document discusses refrigeration and air conditioning systems. It covers topics like principles of refrigeration, vapor compression systems, vapor absorption systems, refrigerants and their properties, refrigeration system components, reciprocating compressors, and principles of air conditioning. Specifically, it describes air refrigeration cycles like open and closed cycles, the reversed Carnot cycle for air refrigeration, and how the coefficient of performance is maximized by decreasing the higher temperature and increasing the lower temperature in the reversed Carnot cycle.
Recuperators are heat exchangers that transfer heat from one fluid stream to another without mixing the fluids. They are commonly used to recover waste heat from exhaust gases to preheat intake air in applications like gas turbines, furnaces, and ventilation systems. This increases efficiency by reducing the amount of fuel or additional heat needed. Recuperators transfer heat through a solid barrier separating the fluid streams and come in designs like plate, tube, or rotary. They provide efficiency gains over alternatives but require maintenance to address deposits on heat transfer surfaces over time.
This document is a presentation about climate and building design given by Dr. Mark Jentsch at a workshop in Oman. It discusses how climate impacts building design and how vernacular architecture has traditionally adapted to local climates. However, modern architecture often ignores climatic considerations. It also addresses how the climate is changing globally due to factors like greenhouse gas emissions, and the need to adapt building design to future climate conditions.
The document discusses kitchen ventilation design and calculations. It explains that an effective kitchen ventilation design requires determining the cubic feet of the kitchen area, calculating additional airflow needed based on appliance size and fuel type, and designing the duct run while accounting for equivalent duct length. Key factors that influence the design include hood location and coverage, appliance recommendations, ceiling height, duct length and turns, and whether makeup air is required.
HVAC systems are designed to heat, cool, and ventilate indoor spaces for human comfort. Heating increases temperature while cooling decreases it. Ventilation maintains indoor air quality through exhaust and fresh air. Air conditioning alters temperature, humidity, and air quality. Common HVAC systems include window units for single rooms, split units with indoor and outdoor components, packaged units for medium loads, and central air for large buildings. Vapor compression is the most widely used refrigeration cycle, involving an evaporator, compressor, condenser, and expansion valve.
Design of air conditioning and ventilation system for a multi storey office b...eSAT Journals
Abstract This project consists of how the proposed centralized air conditioning and mechanical ventilation system is designed and its criterion for a new building in Hyderabad. It consists of seven floors and two basements having an area of 39000sft per floor. The two basement (lower and upper) and major part of ground floor shall be meant for offices with a total area of 273000sft. The main objective is to create a thermally controlled environment within the space of a building envelope such as office space, BMS room, society room, entrance lobby etc. and building mechanical ventilation namely basement ventilation, staircase pressurisation, lift well pressurisation, toilet exhaust etc. Design and planning of the above system shall meet the required below customer objectives, like econoical in cost,energy efficient,simple and flexible with respect to operation and maintenance. The tentative air conditioning load for the system shall be 800TR apprix. Air cooled screw chillers with secondary variable pumping system are proposed to make the system energy efficient. The proposed air conditioning plant shall be located on the sw side on the building terrace. keywords: chillers, variable air volume, air handling unit
The document discusses the history and scientific development of cooling tower design theory. It begins by explaining how Merkel developed the first scientific theory for evaluating cooling tower performance in 1925. It then provides definitions of key cooling tower concepts like approach, range, and heat transfer methods. The document goes on to describe parameters like tower characteristics, fan power requirements, and water loss factors. It also summarizes Merkel's assumptions and the development of generalized supply equations from manufacturer curves.
This document discusses different types of HVAC systems and their applications. It provides information on direct expansion systems versus chilled water systems, package units, split units, air handling units, fan coil units, and chilled water systems. Specific HVAC system considerations and requirements are discussed for different building types like hospitals, hotels, and frozen food storage facilities. Key factors in HVAC system selection include temperature and humidity control, air movement and distribution, filtration, and achieving proper indoor environmental conditions for the building type and use.
An integrated gasification combined cycle (IGCC) power plant converts coal into synthesis gas (syngas) through gasification. The syngas is then cleaned before fueling a combustion turbine to generate electricity. Exhaust heat from the turbine produces steam to drive a steam turbine. This combined cycle configuration achieves high efficiencies. The IGCC plant includes components for coal preparation, gasification, syngas cooling/cleaning, and syngas use in the combustion turbine. Benefits include high efficiency and easier carbon capture, while drawbacks are higher costs and more complex operation than conventional coal plants. Existing IGCC plants are located in the United States but none currently in India.
The presentation discusses the various factors which affect the performance of Power Boilers including the quality of coal, airheater performance, air ingress etc.
The document provides information about a group assignment for a central air conditioning system. It includes definitions of air conditioning and central air conditioning systems. It describes the typical components of a central AC system such as the compressor, air handling unit, return air inlets, cool air dispenser, condenser, and cooling tower. It provides a case study of a water-cooled condenser and explains the cooling process within the condenser and cooling tower. Common problems, maintenance requirements, and advantages/disadvantages of central AC systems are also summarized.
This document discusses various types of equipment that can be used to recover waste heat, including recuperators, regenerators, heat wheels, heat pipes, economizers, shell and tube heat exchangers, plate heat exchangers, and run around coil exchangers. It provides details on the design and operation of each type of equipment and examples of common industrial applications where they are used, such as recovering heat from boiler flue gases, furnaces, dryers, and other processes to improve energy efficiency.
The document provides details about the HVAC and fire protection systems at Subang Parade mall in Malaysia. It discusses the centralized HVAC system, which includes 70 air handling units, 3 cooling towers, and 2 chiller systems. It also describes the fire protection systems, including smoke detectors, sprinklers, fire alarms, and extinguishers. Issues with the existing systems like noise and lack of maintenance are identified. Recommendations are provided to improve the HVAC system with ice storage cooling and update the fire systems with water mist and improved detectors.
Shakil Hossain presented on cooling tower and cooling water circuits. The presentation covered different types of cooling systems including open, closed, and mixed systems. It described the components and types of cooling towers such as natural draught, forced draught, and induced draught towers. The presentation also discussed liquid cooling systems including liquid-to-liquid, closed-loop dry, open-loop evaporative, closed-loop evaporative, and chilled water systems. The key advantages and disadvantages of natural draught, forced draught, and induced draught cooling towers were highlighted.
Este documento describe los intercambiadores de calor plásticos, incluyendo sus ventajas sobre los intercambiadores metálicos, los materiales plásticos comúnmente utilizados y sus rangos de temperatura y presión, y los métodos de diseño y fabricación. Los intercambiadores de calor plásticos son adecuados para aplicaciones agresivas químicamente debido a la inercia química de los plásticos. Se diseñan con diámetros de tubería más pequeños para compensar la baja conductividad té
This document discusses natural draft cooling towers. It begins by defining a cooling tower as a device used to transfer heat and cool water for reuse. It then discusses the types of cooling towers, focusing on natural draft towers. The key components of a natural draft cooling tower are described, including the supply basin, cooling tower, fill material, and drift eliminators. The document explains that natural draft towers use the stack effect and heat transfer between warm water and ambient air to cool the water, which is then recirculated. Finally, it provides some strategies to improve the efficiency of natural draft cooling towers.
This document provides information on estimating hot water demand for plumbing systems. It discusses factors that influence hot water usage and provides estimates of usage for different household activities. Standard fixture units are presented as a method to estimate total hot water demand based on the type and number of fixtures. Flow rates are then estimated based on the total fixture unit count using probability curves.
This document discusses heating and cooling load calculations for buildings. It covers calculating heating loads by estimating transmission heat losses through walls, infiltration, and ductwork. Cooling load calculations are more complex as they consider time-varying outdoor conditions and internal heat gains. Methods for calculating cooling loads include using the Cooling Load Temperature Difference (CLTD) method for walls and roofs and considering solar heat gain factors for windows. The assumptions behind design cooling loads and calculating people loads are also outlined.
Applications of Refrigeration and Air Conditioning & RefrigerantsNITIN AHER
This document discusses refrigeration and air conditioning. It describes how refrigeration cools products or spaces below the surrounding temperature, while air conditioning controls temperature, moisture, cleanliness, odor, and air circulation for occupants or processes. Common applications are listed such as room air conditioners, refrigerators, evaporative coolers, and commercial refrigeration/air conditioning. The document then focuses on evaporative cooling systems, automotive air conditioners, refrigerants used, and criteria for selecting refrigerants including thermodynamic properties, environmental impact, and safety.
Design options for hvac distribution systemsJASON KEMBOI
This document discusses design options for HVAC distribution systems. It describes centralized HVAC systems which have four main components: an energy supply, service generators, distribution components like ducts, and delivery components like diffusers. The document focuses on air distribution design options, which include all-air, all-water, and air-water systems. All-air systems deliver heated or cooled air through ducts, all-water uses water and terminal units, and air-water uses a combination. The best design considers architectural, financial, and performance constraints.
The document discusses the coefficient of performance (COP) as it relates to heat pumps and refrigeration systems. It provides definitions and equations for calculating COP for both heating and cooling applications. Higher COP values indicate greater efficiency, with optimal performance dependent on factors like temperature differences and system design. Real-world COP is typically lower than theoretical maximums due to irreversible processes and other losses.
This document discusses refrigeration and air conditioning systems. It covers topics like principles of refrigeration, vapor compression systems, vapor absorption systems, refrigerants and their properties, refrigeration system components, reciprocating compressors, and principles of air conditioning. Specifically, it describes air refrigeration cycles like open and closed cycles, the reversed Carnot cycle for air refrigeration, and how the coefficient of performance is maximized by decreasing the higher temperature and increasing the lower temperature in the reversed Carnot cycle.
This document provides an overview of gas turbine power cycles and the Joule cycle. It begins by revising gas expansions and compressions, then introduces the basic Joule cycle which consists of four ideal processes - isentropic compression, constant pressure heating, isentropic expansion, and constant pressure cooling. The document discusses efficiency calculations and worked examples for the ideal Joule cycle. It then examines the effects of friction, providing diagrams and equations to model non-isentropic compression and expansion processes. The document concludes by noting some variants in practical gas turbine engines from the basic Joule cycle model.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
The document summarizes a study on recovering waste heat from an air conditioning system. It discusses:
1) The design of a heat recovery system to extract waste heat from an air conditioner's condenser and use it to heat water. Calculations are shown to determine the available heat of 13% that can be recovered.
2) The methodology involves measuring heat extracted during cooling, designing a heat exchanger, and calculating the air conditioner's COP with and without heat recovery to compare efficiency improvements.
3) Technical specifications of the air conditioner used in the study are provided, and the design process is outlined. This includes calculating the refrigeration effect, available desuperheating heat, and mass flow
The document discusses different types of gas turbine cycles including direct open, indirect open, direct closed, and indirect closed cycles. It then focuses on the ideal Brayton cycle and how the net work output varies with pressure ratio, reaching a maximum at a specific pressure ratio. The regenerative Brayton cycle is introduced as an improvement where heat is recouped through a regenerator. Intercooling and reheating are also discussed as ways to further improve the cycle performance. Combined cycles, which use both gas and steam turbines, provide higher efficiencies than gas turbines alone. The ideal jet propulsion cycle for aircraft is described, where the turbine power is only used to drive the compressor.
This document discusses how to calculate cooling requirements for a data center. It explains that the total heat output of the data center needs to be estimated by calculating the heat from IT equipment, UPS systems, lighting, people, and other sources. Common conversion factors and design guideline values are used to convert between measurement units like Watts, BTUs, and tons. A case study then demonstrates how to calculate the heat output subtotals and total for an example data center with details on its IT load, floor area, and staff. It emphasizes that the air conditioning system capacity should be at least 1.3 times the total heat load to ensure adequate cooling and redundancy.
Refrigeration and air conditioning (full note)shone john
Principles of refrigeration: Thermodynamics of refrigeration - Carnot cycle,
reversed carnot cycle, heat pump, and refrigerating machine- coefficient of
performance - unit of refrigeration - refrigeration methods- conventional
refrigeration systems. Air refrigeration system- Bell Coleman cycle - C.O.P.
capacity work and refrigerant flow requirements in Bell - Coleman cycle.
Module 2
Vapour compression system: simple cycle -comparison with Carnot cycle -
theoretical, actual and reactive - COP effect of operating parameters on
COP - wet, dry and superheated compression - under cooling - actual cycle
representation on TS and PH diagrams simple problems. Advanced
vapour compression systems - multistage vapour compression systems -
flash chamber multiple compression and evaporation systems cascading -
simple problems.
Module 3
Vapour absorption systems: simple, cycles - actual cycle - ammonia water
and lithium bromide water systems - COP - electrolux system. Refrigerant
and their properties: Nomenclature - suitability of refrigerants for various
applications - unconventional refrigeration methods- Vortex tube, steamjet, magnetic (cryogenics) refrigeration and thermoelectric refrigeration -
applied refrigeration house hold refrigerators - unit air conditioners andModule 4
Refrigeration system components: condensers - water and air cooled
condensers - evaporative condensers - expansion devises - capillary tubeconstant pressure expansion valve - thermostatic expansion valve - float
valve and solenoid valve - evaporators - natural convection coils - flooded
evaporators - direct expansion coils. Reciprocating compressors: single
stage and multistage compressors - work done optimum pressure ratioeffect of interfolding - volumetric efficiency -effect of clearance -
isothermal and adiabatic efficiency - compressed air motors. Rotodynamic
compressors: Screw and vane type compressors - principle of operation -
hermetic, semihermetic and open type refrigeration compressors.
Module 5
Principles of air conditioning: Psychrometry and psychrometric chart
thermodynamics of human comfort - effective temperature - comfort chart
applied psychrometry - sensible heat factor - psychometric processproblems. Winter air conditioning: heating load calculations humidifiers
and humidistat. Summer air conditioning: cooling load calculations - year
round air conditioning - unitary and central systems - principles of air
distribution - design of air duct systems.
References
1. Refrigeration and air conditioning - Ballaney P. L.
2. Refrigeration and air conditioning - Stocker W. F.
3. Refrigeration and air conditioning - Jordan and Protester
4. Principles of Refrigeration - Roy J. Dossat
1. The document discusses gas turbine cycles with two shafts, where one turbine drives the compressor and the other provides power output. It describes regeneration using a heat exchanger to improve efficiency by heating the compressed air. Intercooling between compression stages and reheating are also discussed to reduce the work of compression. Examples are provided to calculate efficiency, power output, temperatures and pressures at different points in regenerative cycles with variations like intercooling.
This document provides an overview of energy recovery wheels, which are devices that transfer energy between exhaust and supply air streams in HVAC systems. It discusses the principles of sensible and total heat transfer using energy recovery wheels and how they can improve energy efficiency. The document also covers factors like effectiveness, airflow balancing, air transfer between streams, frost control methods, and limitations of using energy recovery wheels with hazardous exhaust air.
1. The document discusses gas power cycles and ideal cycles that approximate internal combustion engines. It focuses on the Otto cycle for spark-ignition engines and the Diesel cycle.
2. The Otto cycle consists of isentropic compression, constant volume heat addition, isentropic expansion, and constant volume heat rejection. The Diesel cycle replaces the constant volume heat addition with constant pressure heat addition.
3. Equations are derived for the thermal efficiency of the Otto and Diesel cycles in terms of the compression ratio and temperature ratios between processes. The temperature ratios depend on whether the specific heats are constant or variable.
Renewable energy sources like wind turbines, solar panels, and heat pumps provide alternatives to fossil fuels but have some limitations. Wind turbines have low capacity factors of 0.25-0.4 and require high upfront costs of £30,000 for a 6kW system. Solar panels cost £2,000-£4,000 installed for a house and save around £60-£92 per year in electricity bills. Photovoltaic solar cells have high costs of 60-70p/kWh currently and may not be cost competitive with retail electricity until after 2025. Ground source heat pumps can provide efficient heating but require extensive piping installed underground that may have long term temperature effects on the soil.
This document discusses the effects of friction on the Joule cycle used in gas turbines. It states that friction reduces the turbine's power output and increases the compressor's power input, resulting in lower net power and thermal efficiency. Diagrams are provided showing how friction lowers the temperature change in both the turbine and compressor processes compared to the ideal case. The document then provides an example calculation for a gas turbine cycle accounting for the isentropic efficiencies of the turbine and compressor due to friction.
The document discusses the second law of thermodynamics. It defines a heat engine as a system that develops net work from a heat supply, requiring both a hot and cold reservoir. The second law states that the gross heat supplied must be greater than the net work done, meaning the efficiency of a heat engine is always less than 100%. Entropy is introduced as a property that enables the representation of heat flow on temperature-entropy diagrams. Such diagrams are shown and described for steam.
The document contains multiple choice and short answer questions related to thermodynamics and heat engines. Some sample questions include identifying the process represented by lines on a T-s diagram, defining key thermodynamic cycles like Otto and Diesel, and calculating efficiency and heat supplied for ideal Brayton cycles. Short answer questions provide definitions for terms like refrigerating capacity and differentiate concepts such as normal and shear stress. Numerical problems involve truss analysis and calculating properties of gas turbine cycles.
The document discusses the first and second laws of thermodynamics. It begins by explaining limitations of the first law, such as heat always flowing from hotter to colder bodies. It then explains what the second law tells us - that not all heat can be converted to work and heat will not flow spontaneously from cold to hot. The second law is then discussed through both the Kelvin-Planck and Clausius statements. Perpetual motion machines are described as violating the second law. The Carnot cycle is then explained in detail as a reversible thermodynamic cycle.
performance analysis and modification of an air conditionerJuvenile Trader
This document summarizes a student project to analyze and modify an air conditioner to improve its performance. The goals are to enable both heating and cooling, evaluate performance at different temperatures, and enhance performance through modifications. It describes the basic vapor compression cycle and processes involved in air conditioning. It also defines and explains various metrics used to measure air conditioner efficiency, such as COP, EER, SEER, and HSPF.
1. The document discusses improving the efficiency of combined cycle power plants through various methods like regeneration, intercooling, and reheating. These processes divide the gas turbine cycle into multiple stages to better approximate ideal cycles.
2. Part-load performance is also important, as efficiency decreases at lower power outputs due to lower air flow rates. Ambient conditions also impact maximum power output and efficiency.
3. Flow rate equations are presented for single and multi-stage turbines, showing how pressure ratio, efficiency, and ambient conditions impact relative flow rates and available power.
The document discusses the limitations of the first law of thermodynamics and introduces the second law of thermodynamics. It explains that the first law does not account for the direction of energy transfer, while the second law states that heat will only flow spontaneously from hotter to colder bodies and not vice versa. The second law also establishes that it is impossible to convert all heat into work in a thermodynamic cycle. Various applications of the first and second laws are described, including heat engines, refrigerators, heat pumps, and the impossibility of building a perpetual motion machine of the second kind.
Similar to Power Knot:: Coefficient of Performance, Energy Efficiency Ratio, and Seasonal Energy Efficiency Ratio (20)
How to Fix the Import Error in the Odoo 17Celine George
An import error occurs when a program fails to import a module or library, disrupting its execution. In languages like Python, this issue arises when the specified module cannot be found or accessed, hindering the program's functionality. Resolving import errors is crucial for maintaining smooth software operation and uninterrupted development processes.
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
How to Make a Field Mandatory in Odoo 17Celine George
In Odoo, making a field required can be done through both Python code and XML views. When you set the required attribute to True in Python code, it makes the field required across all views where it's used. Conversely, when you set the required attribute in XML views, it makes the field required only in the context of that particular view.
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
Power Knot:: Coefficient of Performance, Energy Efficiency Ratio, and Seasonal Energy Efficiency Ratio
1. How Efficient is Your Air Conditioning System? Page 1 of 10
Power Knot LLC
501 Valley Way
Milpitas CA 95035
USA
+1-408-889-8433
www.powerknot.com
COPs, EERs, and SEERs
How Efficient is Your Air Conditioning System?
1 Introduction
This note discusses performances of air conditioning systems, including heat pumps and chillers. It
describes the efficiencies of systems so you can estimate how much energy a system may use. The discus-
sion applies equally to residential, commercial, and industrial systems.
When we talk about the size of an air conditioning system (whether by tons of cooling, BTU/h, or kW), we
are specifying the cooling capacity (power) of the system. The actual electrical power used to operate such
a system is less. As described in this document, the electrical power used is one half to one third (or less)
of the cooling power.1
In the US, the Department of Energy (DoE) set standards for the minimum performance of residential cen-
tral air conditioners and heat pumps and this document lists some of those requirements.
2 Coefficient of Performance, COP
The COP is a measure of the amount of power input to a system compared
to the amount of power output by that system:2
(Eq 1)
The COP is therefore a measurement of efficiency; the higher the number,
the more efficient the system is. The COP is dimensionless because the
input power and output power are measured in Watt. The COP is also an instantaneous measurement in
that the units are power which can be measured at one point in time.
Consider a simple electric heater. All of the electricity that is input to the unit is converted to heat. There is
no waste and the power output (in heat) equals the power input (in electricity), so the COP is one. The
COP can be used to describe any system, not just heating and cooling.
An air conditioning system uses power to move heat from one place to another place. When cooling, the
air conditioning system is moving heat from the space being cooled (usually a room), to somewhere it is
1. It is possible to run air conditioning systems using gas or other power sources. While some parts of this discussion apply
equally to such systems, the focus of this document is on systems driven by electrical power.
2. It is important to distinguish between “energy” and “power.” Energy is the amount of work that is done and is measured in
Joule (J) or British thermal units (BTU). Power is work done in unit time (or the rate of doing work) and is measured in W
(W=J/s) or BTU/h.
COP
power output
power input
-------------------------------=
2. How Efficient is Your Air Conditioning System? Page 2 of 10
COPs, EERs, and SEERs
unwanted (usually outside). A heat pump uses the same principles, but it is moving heat from outside (the
cold side) to the space being heated inside (the living space).
The maximum theoretical COP for an air conditioning system is expressed by Carnot’s theorem, reduced
to the following equation:
(Eq 2)
Where is the cold temperature and is the hot temperature. For space cooling, the cold temperature is
inside the space; for space heating, the cold temperature is outside. All temperatures are expressed in Kel-
vin. To convert from °C to Kelvin, add 273.15. To convert from °F to °C, subtract 32, multiply by 5 and
divide by 9.
As you can see from equation 2, as the difference between the hot temperature and the cold temperature
increases, the COP becomes lower, and vice versa. This means that an air conditioning system is more effi-
cient when the room temperature is closer to the outside temperature and will use more power when there
is a larger difference in these temperatures.
As an example, consider the maximum theoretical efficiency of an air conditioning system that is cooling a
room to 23°C (73.4°F). If the outside air temperature is 32°C (89.6°F), the theoretical maximum efficiency
is:
(Eq 3)
Typical COP values for air conditioning and heat pump systems are in the range 2 to 4, or about a tenth of
the theoretical maximum. However, this helps to explain where the power is used in such a system. Con-
sider the heat pump application shown in figure 1.
The heat pump takes power from the environment and uses electrical power to move that power to the
inside space. More power is put into the house than used in electricity.1
The COP of this system is 4
(power into the house ÷ power consumed). Observe that the electrical power consumed goes into the build-
ing. In practice some is expended as heat outside the building, so the actual COP will be slightly less than
4.
An air conditioner operates in the same way, but it is removing power from the space. Consider the figure
in reverse where 1 kW is used to move 3 kW of power from the space. The air conditioner puts 4 kW of
power into the environment and this power must be dissipated by the condenser. The air conditioning unit
is using more power than is being consumed in electricity. However, in this case, all the power used to
operate the air conditioning unit is dissipated outside and has no effect on the power removed from the
space. Hence, the COP is equal to 3.
1. The figure uses the term “heat.” Heat is energy, not power, but is used here to aid in the understanding.
COPmaximum
TC
TH T–
-----------------=
TC TH
COPmaximum
TC
TH TC–
--------------------
23 273.15+( )
32 273.15+( ) 23 273.15+( )–
------------------------------------------------------------------------- 32.9= = =
3. How Efficient is Your Air Conditioning System? Page 3 of 10
COPs, EERs, and SEERs
3 Energy Efficiency Ratio, EER
The EER is the ratio of output cooling energy (in BTU) to electrical input energy (in
Watt-hour).
(Eq 4)
The units are therefore or more formally .
The bizarre units of measurement originated in the US to measure the efficiency of an
air conditioning system in a steady state. The units are therefore not dimensionless and
EER can be measured only over time. Typically, with the system stable, one can measure the energy used
over an hour period. One measures the amount of cooling the system has performed during that time.
Many writers erroneously consider the EER to be a ratio of power, not energy:
(Eq 5)
The units are the same, but now we are dividing the power of the air conditioning unit (in BTU/h) by the
power to operate it (in Watt). Although incorrect, this view does have the advantage of allowing us to eas-
ily estimate the power used for a certain size of air conditioning unit.
Figure 1. Example of operation of a heat pump
EER
output cooling energy in BTU
input electrical energy in Wh
------------------------------------------------------------------------=
BTU W h⁄⁄ BTU W
1–
h
–
⋅ ⋅
EERerroneous
output cooling power in BTU/h
input electrical power in W
---------------------------------------------------------------------------=
4. How Efficient is Your Air Conditioning System? Page 4 of 10
COPs, EERs, and SEERs
As an example, consider an air conditioning unit that is five tons and has an EER of 11.6.1 If we want to
find out how much power is used we rewrite equation 5:
(Eq 6)
Where the multiplication by 12,000 converts tons of air conditioning to BTU/h.
The EER can be specified only at a specific delta temperature (between inside and outside the space being
cooled), because as we see from equation 2, the efficiency changes with this delta temperature. The EER is
usually specified under the conditions shown in table 1.
To convert EER to COP, we need to accommodate for the units used. We convert the BTU energy and the
electrical input energy to a common energy unit, namely Joule.2
One BTU equals 1055 J. One Wh equals
3600 Ws or 3600 J. So:
(Eq 7)
Alternatively:
(Eq 8)
4 Seasonal Energy Efficiency Ratio, SEER
As with EER, the SEER is the ratio of output cooling energy (in BTU) to electrical
input energy (in Watt-hour). However the SEER is a representative measurement of
how the system behaves over a season where the outdoor temperature varies:
(Eq 9)
1. To understand the meaning of a ton of air conditioning, please review Power Knot’s application note on this topic available at
www.powerknot.com.
Dry bulb
temperature
Wet bulb
temperature
Relative
humidity Dew Point
Outdoor conditions 95°F (35°C) 75°F (24°C) 40% 67°F (19°C)
Indoor conditions 80°F (27°C) 67°F (19°C) 51% 60°F (16°C)
Table 1. Usual test conditions to evaluate EER
2. The symbol for Joule is J. One Joule is equal to one Watt-second (Ws).
input electrical power
output cooling power in BTU/h
EER
---------------------------------------------------------------------------
5 12000×
11.6
------------------------ 5.17 kW= = =
COP
output cooling energy
input electrical energy
----------------------------------------------------- EER BTU/(Wh)
1055J/BTU
3600J/(Wh)
-----------------------------× EER 0.293×= = =
EER COP 3.41×=
SEER
output cooling energy in BTU over a season
input electrical energy in Wh during the same season
-------------------------------------------------------------------------------------------------------------------------------=
5. How Efficient is Your Air Conditioning System? Page 5 of 10
COPs, EERs, and SEERs
The US DoE defined the formula to be used to calculate SEER values for residential air conditioning sys-
tems of less than 65,000 BTU/h (19 kW). The manufacturer makes EER or COP measurements at various
values for indoor and outdoor temperature and then computes the SEER. The result is one number that
may guide a prospective purchaser or owner of a system to compare one unit with another unit.1
As an example, consider a five ton unit (60,000 BTU/h) that runs on average eight hours a day during the
cooling season.2
At the ends of the season, the system may run only four hours a day but at the peak of the
season, it is running 14 hours a day. Assume the cooling season is 180 days (about six months). Again,
assume that on average throughout the season, the unit runs at two thirds of its capacity. The cooling
energy is:
(Eq 10)
If the system has a SEER of 13, the total electrical energy used is:
(Eq 11)
If the cost of electricity is 17 ¢ per kWh, the cost to run this air conditioning unit during the season is:
(Eq 12)
The EER is usually specified under the conditions shown in table 1. The SEER is averaged over a range of
temperatures that are less than or equal to this, including one test where the outside temperature is 82°F
(28°C) and the inside temperature is 80°F (27°C). We know that as the delta temperature goes down, the
efficiency goes up, so therefore the SEER is greater than the EER (typically by about 15% to 35%). One
formula, to convert between the two was proposed by a student in a master’s thesis as follows:3
(Eq 13)
Therefore:
(Eq 14)
For example, if EER is 12, the estimated SEER is 14.4, calculated as follows:
(Eq 15)
1. Again, ostensibly, a system with a higher SEER will consume less energy than a system with a lower SEER.
2. The cooling season is typically summer, but the US DoE specifically uses the term “cooling season.”
3. This formula seems to have been widely accepted, but this author cannot find the original document. It is referenced in a US
DoE document titled Building America House Simulation Protocols, June 2010 and attributed to Wassmer (2003).
cooling energy in season 60000 BTU/h
2
3
--- 8 h/day 180 days××× 57.6 10
6
BTU×= =
electrical energy in season
57.6 10
6
×
13
------------------------- 4.43 MWh= =
cost to operate the a/c unit in the season 4.43 MWh $0.17/kWh× $753= =
EER 1.12 SEER× 0.02 SEER
2
×–=
SEER
1.12 1.2544 0.08 EER×––
0.04
-----------------------------------------------------------------------=
SEER
1.12 1.2544 0.08 12×––
0.04
------------------------------------------------------------------ 14.4= =
6. How Efficient is Your Air Conditioning System? Page 6 of 10
COPs, EERs, and SEERs
This implies SEER is 20% more, but in practice the value may be larger.1 Also, because the conditions to
calculate the SEER are fixed, they may differ widely from where the air conditioning unit is actually
installed where temperatures and operating parameters vary significantly. Therefore, the actual ratio
observed in practice may differ widely from the published SEER, making it difficult to accurately estimate
the energy to run the system during a season.
In the US, the DoE specifies the minimum values for SEER as shown in table 2. The law was changed in
January 2006 and the table lists the old and new standards.
A split system is one where the evaporator and condenser are in physically different places. The compres-
sor is usually housed with the condenser and these are in one package that is usually installed outside or on
a roof. The metering device (expansion device) is adjacent to the evaporator and installed inside the space
where the air used to cool the space can flow.
A packaged system has all four major components (evaporator, condenser, metering device, and evapora-
tor) in a single unit that is usually placed outside. Air ducts transport the supply and return air to the unit.
Using equation 9, we see that a unit that is rated at SEER of 13 is 30% more efficient than a unit rated at
SEER 10.
5 Heating Seasonal Performance Factor (HSPF)
Like SEER, this is a measurement of the efficiency of a system and the units are the same (BTU/h divided
by Watt). However, this measures the efficiency of the system in heating mode, not cooling mode. There-
fore it applies only to heat pumps or reversible air conditioning units and not to units that only cool a
space. A variant of equation 7 on page 4 applies:
(Eq 16)
As with COP, EER, and SEER, the higher the number of HSPF the greater the efficiency.
In the US, the DoE specifies the minimum values for HSPF as shown in table 3. The law was changed in
January 2006 and the table lists the old and new standards.
For example, Assume a system has an HSPF of 8. Then from equation 16, the COP is 2.3. This means that
2.3 times the amount of heat is put into the space than is consumed in electricity. Put another way, for
every 1 kWh of electrical energy used by the heat pump, 2.3 kWh of heat energy is input to the space.
1. If you are evaluating two different air conditioning systems, compare the EER of one to the EER of the other, or compare the
SEER of one to the SEER of the other. It is not valid to compare the EER of one unit with the SEER of another unit.
1994 to 2006 After January 2006
Split systems 10 13
Packaged systems 9.7 13
Table 2. Minimum SEER standards for new residential installations in the USA
COP
output heating energy
input electrical energy
----------------------------------------------------- HSPF 0.293×= =
7. How Efficient is Your Air Conditioning System? Page 7 of 10
COPs, EERs, and SEERs
6 Kilo-Watt per Ton (kW/ton)
The efficiencies of large industrial air conditioner systems, especially chillers, are given
in kW/ton to specify the amount of electrical power that is required for a certain power of
cooling. In this case, a smaller value represents a more efficient system. However, as we
have seen, to be valid, this number must be reported at various operating conditions, espe-
cially the indoor and outdoor temperatures, and the difference between chilled water
return and chilled water supply.
You can convert kW/ton to COP as follows:
(Eq 17)
Because a ton of refrigeration is equivalent to 3.517 kW.
For example, if a chiller has a rating of 1.8 kW/ton, then using equation 17, the COP is 1.95. Therefore, for
every 1 kW of power consumed by the chiller, it will provide 1.99 kW of cooling in the space.
7 Horse Power
Another unit in use in the US is the horse power (HP). This is a unit of power and
typically is used to specify the size of motors. It may also be used to specify the
input power of an air conditioning system. One HP is approximately 746 W.
8 Energy Star
In the US, Energy Star is the Environmental Protection Agency’s (EPA’s) indica-
tion for products that have high energy efficiency. it makes it easy for consumers to identify and purchase
products that have higher energy efficiency than those products without such designation.
Systems under 65,000 BTU/h (19 kW) can earn the Energy Star symbol by meet-
ing the minimum efficiency ratings listed in table 4. The numbers in parentheses
are those values that must be met to qualify for a Federal tax credit. The ratings for
HSPF apply only to systems that combine a heat pump.
1994 to 2006 After January 2006
Split systems 6.8 7.7
Packaged systems 6.6 7.7
Table 3. Minimum HSPF standards for new residential installations in the USA
COP
power output in W
power input in W
---------------------------------------------
3.517
kW/ton
------------------= =
8. How Efficient is Your Air Conditioning System? Page 8 of 10
COPs, EERs, and SEERs
9 References
Details about Energy Star (US EPA) are here:
http://www.energystar.gov
The DoE web site with many references for residential systems is:
http://www1.eere.energy.gov/buildings/appliance_standards/residential/central_ac_hp.html
The document 10 CFR Part 430, titled “Energy Conservation Program for Consumer Products: Test Proce-
dure for Residential Central Air Conditioners and Heat Pumps; Final Rule,” October 2007 describes the
test procedures to used to evaluate EER, SEER, and HSPF.
It is interesting to read the discussion regarding the introduction of these news rules. Two subjects were
broached that were not included in the new rules:
• Setting a minimum EER. It was proposed that the minimum EER should be set at 11.6. However, it
was concluded that specifying the minimum SEER was a good way of ensuring the efficiencies
required.
• Mandating the use of a thermal expansion valve (TXV) for all systems. Previously, fixed orifices were
permitted for the metering device; the DoE concluded that the TXV can make a system 11% more
efficient. However, it was eventually decided that the DoE should not dictate the technology used, so
the mandate was dropped. In practice, however, most manufacturers adopted the use of a TXV to
improve the efficiency of the systems they manufacture.
Also, when the new standards were proposed, two of the largest US manufacturers of these systems
opposed the rules.
The values for EER, SEER, and HSPF are specified in Standard 210/240 by the Air-Conditioning, Heating
and Refrigeration Institute (AHRI) “2008 Standard for Performance Rating of Unitary Air-Conditioning
and Air-Source Heat Pump Equipment.” You can freely access this document here:
http://www.ahrinet.org/Content/FindaStandard_218.aspx
The DoE also refers to Standard 90.1-2010 by the American Society of Heating, Refrigerating and Air-
Conditioning Engineers (ASHRAE) “Energy Standard for Buildings Except Low-Rise Residential Build-
ings.” You can buy this document ($125 USD at the time of this document) here:
http://www.techstreet.com/standards/ASHRAE/90_1_2010_I_P_?product_id=1739526
EER SEER HSPF
Split systems 12 (≥12.5) 14.5 (≥15) 8.2 (≥8.5)
Packaged systems 11 (≥12) 14 (≥14) 8 (≥8)
Table 4. Energy Star ratings for air-source heat pumps and central air conditioners
9. How Efficient is Your Air Conditioning System? Page 9 of 10
COPs, EERs, and SEERs
The ASHRAE web site is:
http://www.ashrae.org/
10 Summary of Performance Requirements
The following tables list the minimum performance standards that must be met for new installations of air
conditioning systems in the US as of the date of this document. This is not an exhaustive or comprehensive
list and the requirements change as technology improves.
You can see from the table that the input power in W is approximately equal the cooling capacity in BTU/
h divided by ten. This is a very approximate guide that allows you estimate the size of current clamps that
you may need if you want to monitor such a system.
Type
Size of System (Cooling Power) Minimum Efficiency Input
power,
kWa
a. Input power is derived using equation 1 on page 1.
BTU/h kWb
b. 1,000 BTU/h = 293.1 W.
Tonsc
c. 1 ton of cooling power = 12,000 BTU/h.
EER,
SEER COPd
d. COP values are obtained using equation 7 on page 4 and equation 13 on page 5. These are approximate conversions
and apply only at the conditions under which SEER or EER is specified.
Through the wall air cooled air
conditioner
<30,000 <8.8 <2.5 SEER 12 3.1 <2.8
Small duct, high velocity air
cooled air conditioner
<65,000 <19 <5.4 SEER 10 2.7 <7.1
Other air cooled air conditioners <65,000 <19 <5.4 SEER 13 3.3 <5.8
Other air cooled air conditioners 65k ~
135k
19 ~ 40 5.4 ~ 11.3 SEER 11.2 2.9 6.5 ~ 13.5
Other air cooled air conditioners 135k ~
240k
40 ~ 70 11.3 ~ 20 SEER 11 2.9 13.6 ~
24.3
Other air cooled air conditioners 240k ~
760k
70 ~ 223 20 ~ 63 SEER 10 2.7 26.1 ~
82.5
Other air cooled air conditioners >760,000 >223 kW >63 SEER 9.7 2.6 >84.7
Water cooled air conditioners <65,000 <19 <5.4 EER 12.1 3.6 <5.4
Water cooled air conditioners 65k ~
135k
19 ~ 40 5.4 ~ 11.3 EER 11.5 3.4 5.7 ~ 11.7
Water cooled air conditioners >135,000 >40 >11.3 EER 11 3.2 >12.2
Table 5. Selective sample of minimum efficiencies of air conditioning systems in the US