This document summarizes how air conditioning systems work and some of their drawbacks. A basic system uses a fan to blow air over a cold surface to cool it and a warm surface to heat it back up. Larger building systems circulate chilled water to cool ducted air. The cooling process involves evaporating a refrigerant like Freon that is then compressed, condensing it back to liquid. While effective for temperature control, air conditioning wastes energy and space. It also makes precise humidity and temperature control difficult without risking high costs or side effects. Specifications need to consider the building and needs, not just copy standards.
What is meant by “Airconditioning”?
Human Comfort
Why do we need A.C.?
Advantages and Disadvantage of A.C.
Ideal room temperature
some terminology-
Dry-bulb temperature
Wet-bulb temperature:
Dew point
Latent heat
Absolute humidity
Relative humidity
Specific humidity
Sensible heat
Evaporating Cooling
Condensation
Enthalpy
Entropy
7. Classification of air conditioners
8. Windows AC- advantages
Parts of the Window Air Conditioners
Working
The refrigeration system,
Air circulation system-room air cycle and
The hot air cycle.
Ventilation system,
Control system,
electrical protection system.
9.Split or Ductless AC-
Advantages, parts indoor and outdoor,
Types-
Wall mounted
Floor mounted/Tower AC
Ceiling mounted/Cassette AC
Multi Split ACs
10. Central Air Conditioning System
Advantages and disadvantages
11. Key differences between "Window", "Split" and a "cassette" air conditioners.
12. Cooling capacity
13. Energy Efficiency
14.Energy Consumption
15.Energy Efficiency Ratio
16.Energy Saving Methods
17.Some AC brands
What is meant by “Airconditioning”?
Human Comfort
Why do we need A.C.?
Advantages and Disadvantage of A.C.
Ideal room temperature
some terminology-
Dry-bulb temperature
Wet-bulb temperature:
Dew point
Latent heat
Absolute humidity
Relative humidity
Specific humidity
Sensible heat
Evaporating Cooling
Condensation
Enthalpy
Entropy
7. Classification of air conditioners
8. Windows AC- advantages
Parts of the Window Air Conditioners
Working
The refrigeration system,
Air circulation system-room air cycle and
The hot air cycle.
Ventilation system,
Control system,
electrical protection system.
9.Split or Ductless AC-
Advantages, parts indoor and outdoor,
Types-
Wall mounted
Floor mounted/Tower AC
Ceiling mounted/Cassette AC
Multi Split ACs
10. Central Air Conditioning System
Advantages and disadvantages
11. Key differences between "Window", "Split" and a "cassette" air conditioners.
12. Cooling capacity
13. Energy Efficiency
14.Energy Consumption
15.Energy Efficiency Ratio
16.Energy Saving Methods
17.Some AC brands
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).
This topic explains the importance of ventilation in a building. Identification on types of ventilation and air conditioning system, methods of installation of air conditioning system and its components.
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).
This topic explains the importance of ventilation in a building. Identification on types of ventilation and air conditioning system, methods of installation of air conditioning system and its components.
using different refrigerants as working fluid,the variation in the dimensional parameters of evaporator ,compressor,condenser and expansion device are shown.
Heat Recovery System in Domestic RefrigeratorIjrdt Journal
Refrigeration is a process in which work is done to move heat from one location to another. Refrigeration technology has rapidly evolved in last century from ice harvesting to temperature controlled rail cars. Most widely used current application of refrigeration is for air-conditioning of homes and public buildings. During refrigeration, heat from the refrigerant is dissipated for the successful completion of a refrigeration cycle. In normal household refrigerators, the heat from the refrigerant is removed using a condenser where the refrigerant cools and the air surrounding the condenser heats up. The strategy of how to recover the dissipated heat to develop a waste heat recovery system is relevant. The energy lost in waste heat cannot be fully recovered. However, much of the heat can be recovered and the loss can be minimized by adopting different measures. Hot air can be used for space heating, industrial drying, preheating aspirated air for oil burners, or any other application requiring warm air. The purpose of this project is to demonstrate the technical feasibility of a heat recovery system to recover waste heat from the condenser in the refrigerator and to reuse it for heating application.
ENERGY AUDIT presentationin power system .pptxReshevSharma
An energy audit is a systematic process of evaluating and analyzing energy usage in a building, facility, or industrial process to identify opportunities for energy efficiency improvements, cost savings, and environmental sustainability. The goal of an energy audit is to assess energy consumption patterns, identify areas of inefficiency or waste, and recommend measures to optimize energy usage and reduce overall energy consumption.
Here's an overview of the typical steps involved in conducting an energy audit:
1. **Pre-Audit Planning:**
Define the scope and objectives of the energy audit, including the areas or systems to be evaluated, the level of detail required, and the desired outcomes. Identify key stakeholders, establish audit goals, and gather relevant documentation, such as utility bills, building plans, and equipment specifications.
2. **Data Collection and Analysis:**
Collect comprehensive data on energy consumption, including utility bills, meter readings, and operational data
It will help to the students of Mechanical Engineering. These notes are according to HVAC Subject. Some important topics are here for your good understanding. These are written in easy language, u can understand easily.
Air conditioners, also known as ACs or air con, are a common sight in many households, businesses, and public spaces around the world. They are used to cool down the air and regulate the temperature and humidity levels in a room or building, making it more comfortable for people to work, sleep, or relax. But how do air conditioners actually work?
The State Energy Efficiency Scorecard: Florida ranks 28th in ACEEE's State and Local Policy Database. via American Council for an Energy Efficient Economy
Energy Conservation Contract via NEED Project (National Energy Education Development)
Students discuss with their families the energy they use for everyday activities and educate them about energy saving behaviors and methods using the Household Ratings Guide.
Should You Have Your Air Ducts In Your House Cleaned? Via Environmental Protection Agency (EPA). Some research suggests that cleaning heating and cooling system components (e.g., cooling coils, fans and heat
exchangers) may improve the efficiency of your system, resulting in a longer operating life, as well as some energy and maintenance cost savings. However, little evidence exists that cleaning only the ducts will improve the efficiency of the system.
HVAC Insider: SW FL Rheem Team Partners with Edison Restaurant {article page 8A}. The South West Florida Rheem Team is a group of top Rheem HVAC contractors who work together to contribute to their local/ global community. The group was created more than 10 years ago with six contractors. Today the Team has grown to 12 contractors in the Ft. Myers area. As the membership has grown, so has its commitment to serve the local community. The group meets each month at the Edison Restaurant to discuss community outreach and marketing initiatives. The Edison manager Daniel Kearns mentioned at the Team’s April meeting that they were hoping to cool the outside patio during the hot summer months. Due to the long-standing relationship with the Edison, and its stature as a community landmark, the Rheem Team was happy to help! The SW Florida Rheem Team came up with the concept of creating ‘portable AC units’ that could be ‘rolled’ out during extreme weather to cool off the patio. Within a month, the units were donated –– free of charge –– to the Edison and quickly working to cool off the outside deck and patio.
Premium MEAN Stack Development Solutions for Modern BusinessesSynapseIndia
Stay ahead of the curve with our premium MEAN Stack Development Solutions. Our expert developers utilize MongoDB, Express.js, AngularJS, and Node.js to create modern and responsive web applications. Trust us for cutting-edge solutions that drive your business growth and success.
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Falcon stands out as a top-tier P2P Invoice Discounting platform in India, bridging esteemed blue-chip companies and eager investors. Our goal is to transform the investment landscape in India by establishing a comprehensive destination for borrowers and investors with diverse profiles and needs, all while minimizing risk. What sets Falcon apart is the elimination of intermediaries such as commercial banks and depository institutions, allowing investors to enjoy higher yields.
What are the main advantages of using HR recruiter services.pdfHumanResourceDimensi1
HR recruiter services offer top talents to companies according to their specific needs. They handle all recruitment tasks from job posting to onboarding and help companies concentrate on their business growth. With their expertise and years of experience, they streamline the hiring process and save time and resources for the company.
Enterprise Excellence is Inclusive Excellence.pdfKaiNexus
Enterprise excellence and inclusive excellence are closely linked, and real-world challenges have shown that both are essential to the success of any organization. To achieve enterprise excellence, organizations must focus on improving their operations and processes while creating an inclusive environment that engages everyone. In this interactive session, the facilitator will highlight commonly established business practices and how they limit our ability to engage everyone every day. More importantly, though, participants will likely gain increased awareness of what we can do differently to maximize enterprise excellence through deliberate inclusion.
What is Enterprise Excellence?
Enterprise Excellence is a holistic approach that's aimed at achieving world-class performance across all aspects of the organization.
What might I learn?
A way to engage all in creating Inclusive Excellence. Lessons from the US military and their parallels to the story of Harry Potter. How belt systems and CI teams can destroy inclusive practices. How leadership language invites people to the party. There are three things leaders can do to engage everyone every day: maximizing psychological safety to create environments where folks learn, contribute, and challenge the status quo.
Who might benefit? Anyone and everyone leading folks from the shop floor to top floor.
Dr. William Harvey is a seasoned Operations Leader with extensive experience in chemical processing, manufacturing, and operations management. At Michelman, he currently oversees multiple sites, leading teams in strategic planning and coaching/practicing continuous improvement. William is set to start his eighth year of teaching at the University of Cincinnati where he teaches marketing, finance, and management. William holds various certifications in change management, quality, leadership, operational excellence, team building, and DiSC, among others.
RMD24 | Debunking the non-endemic revenue myth Marvin Vacquier Droop | First ...BBPMedia1
Marvin neemt je in deze presentatie mee in de voordelen van non-endemic advertising op retail media netwerken. Hij brengt ook de uitdagingen in beeld die de markt op dit moment heeft op het gebied van retail media voor niet-leveranciers.
Retail media wordt gezien als het nieuwe advertising-medium en ook mediabureaus richten massaal retail media-afdelingen op. Merken die niet in de betreffende winkel liggen staan ook nog niet in de rij om op de retail media netwerken te adverteren. Marvin belicht de uitdagingen die er zijn om echt aansluiting te vinden op die markt van non-endemic advertising.
Personal Brand Statement:
As an Army veteran dedicated to lifelong learning, I bring a disciplined, strategic mindset to my pursuits. I am constantly expanding my knowledge to innovate and lead effectively. My journey is driven by a commitment to excellence, and to make a meaningful impact in the world.
"𝑩𝑬𝑮𝑼𝑵 𝑾𝑰𝑻𝑯 𝑻𝑱 𝑰𝑺 𝑯𝑨𝑳𝑭 𝑫𝑶𝑵𝑬"
𝐓𝐉 𝐂𝐨𝐦𝐬 (𝐓𝐉 𝐂𝐨𝐦𝐦𝐮𝐧𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬) is a professional event agency that includes experts in the event-organizing market in Vietnam, Korea, and ASEAN countries. We provide unlimited types of events from Music concerts, Fan meetings, and Culture festivals to Corporate events, Internal company events, Golf tournaments, MICE events, and Exhibitions.
𝐓𝐉 𝐂𝐨𝐦𝐬 provides unlimited package services including such as Event organizing, Event planning, Event production, Manpower, PR marketing, Design 2D/3D, VIP protocols, Interpreter agency, etc.
Sports events - Golf competitions/billiards competitions/company sports events: dynamic and challenging
⭐ 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐝 𝐩𝐫𝐨𝐣𝐞𝐜𝐭𝐬:
➢ 2024 BAEKHYUN [Lonsdaleite] IN HO CHI MINH
➢ SUPER JUNIOR-L.S.S. THE SHOW : Th3ee Guys in HO CHI MINH
➢FreenBecky 1st Fan Meeting in Vietnam
➢CHILDREN ART EXHIBITION 2024: BEYOND BARRIERS
➢ WOW K-Music Festival 2023
➢ Winner [CROSS] Tour in HCM
➢ Super Show 9 in HCM with Super Junior
➢ HCMC - Gyeongsangbuk-do Culture and Tourism Festival
➢ Korean Vietnam Partnership - Fair with LG
➢ Korean President visits Samsung Electronics R&D Center
➢ Vietnam Food Expo with Lotte Wellfood
"𝐄𝐯𝐞𝐫𝐲 𝐞𝐯𝐞𝐧𝐭 𝐢𝐬 𝐚 𝐬𝐭𝐨𝐫𝐲, 𝐚 𝐬𝐩𝐞𝐜𝐢𝐚𝐥 𝐣𝐨𝐮𝐫𝐧𝐞𝐲. 𝐖𝐞 𝐚𝐥𝐰𝐚𝐲𝐬 𝐛𝐞𝐥𝐢𝐞𝐯𝐞 𝐭𝐡𝐚𝐭 𝐬𝐡𝐨𝐫𝐭𝐥𝐲 𝐲𝐨𝐮 𝐰𝐢𝐥𝐥 𝐛𝐞 𝐚 𝐩𝐚𝐫𝐭 𝐨𝐟 𝐨𝐮𝐫 𝐬𝐭𝐨𝐫𝐢𝐞𝐬."
Unveiling the Secrets How Does Generative AI Work.pdfSam H
At its core, generative artificial intelligence relies on the concept of generative models, which serve as engines that churn out entirely new data resembling their training data. It is like a sculptor who has studied so many forms found in nature and then uses this knowledge to create sculptures from his imagination that have never been seen before anywhere else. If taken to cyberspace, gans work almost the same way.
Putting the SPARK into Virtual Training.pptxCynthia Clay
This 60-minute webinar, sponsored by Adobe, was delivered for the Training Mag Network. It explored the five elements of SPARK: Storytelling, Purpose, Action, Relationships, and Kudos. Knowing how to tell a well-structured story is key to building long-term memory. Stating a clear purpose that doesn't take away from the discovery learning process is critical. Ensuring that people move from theory to practical application is imperative. Creating strong social learning is the key to commitment and engagement. Validating and affirming participants' comments is the way to create a positive learning environment.
1. How air conditioning works
The essential ingredients in an air conditioning system are a fan to blow air around, a cold
surface to cool and dehumidify the air, a warm surface and a source of water vapour. In a
large system there will also be a tangle of tubes to distribute the air and collect it again.
Notice that the cold surface has two independent jobs to do: it is used to cool the air and it is
also used to dehumidify, by condensing water from the air. This means that the air is cooled
more than is necessary for temperature control, so that it must be heated again afterwards.
Air conditioning wastes energy. It also wastes space, because air has to be pumped around in
quite large tubes, so that it doesn't make a rushing noise. It does, nevertheless, generate a
disturbing background noise if the room is otherwise quiet. There is worse news to come: air
conditioning is spreading to more and more buildings in climates that we once thought were so
mild that they would be immune.
The origin of this technological epidemic is not the subject of this article. I will however
mention some reasons which are relevant to museum conservators. Modern museums, and old
ones as well, are showpieces designed to be admired for bold and original architecture. They
tend to be massive, and those old museums which originally had courtyards to give light and
air are now glassed over with domes and atria. The heat and moisture cannot easily escape to
the outside: they have now to be pumped out.
The subtle elegance of buildings designed for their purpose counts for little nowadays. Grand
Gestures are fashionable, and air conditioning hides the architects' and engineers' lack of
understanding or respect for natural ventilation. One must say that conservators have
reinforced this trend, because they have set specifications for allowable variation of
temperature and relative humidity that can only be achieved by mechanical air conditioning.
1
2. The purpose of this article is to explain how air conditioning works, in order to show why one
cannot just pluck values from some standard or recommendation without risking unexpected
penalties in energy use, maintenance cost and noise. Furthermore, once the mess of steel boxes
and ducts is installed, you cannot dial the temperature and humidity exactly as you want them
without risking surprisingly expensive side effects of energy consumption, climatic instability
and hidden condensation.
I will describe two typical systems. The first is air conditioning for a single room, the second is
a full system for a large building. Most of the available literature, particularly on the internet,
takes it for granted that air conditioning is a good thing and then proceeds to tell you how to
design it. This article is designed to help you understand other people's designs, and judge
their suitability for your purpose.
Simple air conditioning
A fan draws air from the room first through a cooling device, consisting of metal fins
extending from a pipe through which cooling fluid circulates, at a rate determined by the
thermostat or by the humidistat. The air next passes over a heater, usually electrical, which is
energised on instructions from the room thermostat.
Figure 2. Minimal air conditioning. The part of the system in the room, on the left, pulls air
first over a cool surface and then over a warming surface. The part of the system on the right
recirculates the cooling fluid. The fluid passes from the reservoir through a valve B into the
lower pressure within the cooling unit in the room. There the liquid boils, removing heat from
the air. The boiling point is fixed by the constant pressure set by valve A. The vapour is then
compressed and condensed back into a liquid which collects in the reservoir ready for
another cycle.
2
3. Air conditioning has in the past been used where the climate is too hot for comfort. Cooling
will increase the relative humidity of the air, so humidification is not usually built into these
systems. If it is necessary, the usual method is to inject steam from electrically boiled water.
That is all there is to the part of the system in the room, which is sketched on the left in figure
2. The bit that is more difficult to understand, or at least unfamiliar to most people, is how the
cooling fluid is produced and controlled. That is the part on the right of the diagram.
The cooling fluid used to be a chlorofluorocarbon compound, and often still is, though they all
more or less ravage the earth's ozone layer. The essential characteristics of these fluids is that
they have quite a low boiling point at atmospheric pressure and that they can stay in the pipes
for a long time without decomposing either themselves or the pipes. Finally they need to have
some lubricating ability, or the ability to carry a lubricant, because the fluid has to be
compressed and pumped round the system. This rare set of necessary properties has proved
difficult to combine with friendliness to the earth's atmosphere.
The liquid is let into the cooling unit through a valve marked B on the diagram. It evaporates
while it passes through the pipe, taking heat from the air just as water evaporating from a
towel laid on your fevered brow cools you when on holiday in the Mediterranean. The
temperature in the cooling coil depends partly on the amount of fluid let in by the valve, which
is controlled by the thermostat or the humidistat. But now comes a crucial difference from
your Mediterranean experience: the minimum temperature at the cold surface can be fixed by
controlling the pressure in the cooling coil, with the valve marked A on the diagram. The
boiling point of any liquid depends on the pressure. One could use water in the cooling coil, if
the pressure is kept low enough. At 1000 Pa pressure, which seems a lot but is just 1% of
atmospheric pressure, water boils at 7 degrees. It isn't used in cooling coils of this evaporative
type because it has practical disadvantages.
The reason for wanting to limit the minimum temperature is to stop ice clogging the air
passage. There are clever systems which notice when ice has formed and hold a melting pause,
but that adds to the cost. The pressure controller is therefore set to make the cooling fluid boil
at the lowest temperature that is likely to be needed to control the humidity, but always over
zero degrees. The temperature needed for cooling is nearly always higher than that needed for
dehumidification so it is the RH setting that is decisive.
This brings me to the first point that conservators need to understand: it is expensive to
produce air at a dew point below about 4 degrees in this type of equipment. This
dewpoint corresponds to 50% RH at 15°C. This sort of air conditioning is entirely suitable for
keeping people comfortable but it is not good for specialised stores, for films or for furs, for
example, where one needs a temperature below 15 degrees. Such equipment is, however,
often used for such places. A better solution is to use an absorption dehumidifier, which will
be described in a later article.
Now back to the main story: The vapour that emerges through the pressure controller is
gathered up by a compressor. The compression also heats the gas, as will be understood by
anyone who has pumped up a cycle tyre. The hot gas is then led away from the room, to be
cooled down. This is often done on the roof or in a small enclosure which vibrates to the roar
of the fan blowing air over the fins of a condenser. The cooled, now liquid coolant is piped
back to the reservoir, ready for its next tour through the room air conditioner.
3
4. The entire process described above is inefficient and uses electricity, which is itself produced
by inefficient conversion of heat energy. Such systems are therefore confined to small places
where the inefficiency is compensated by the generally high reliability and freedom from
maintenance.
Large air conditioning systems
Figure 3. A large air conditioning system functions much like that described in figure 2,
except that chilled water is used to cool the air. Outside air is drawn in, filtered and heated
before it passes through the main air conditioning devices. The coloured lines in the lower
part of the diagram show the changes of temperature and of water vapour concentration (not
RH) as the air flows through the system.
The principle of operation is the same as that of the small system described above except that
the cooling fluid is usually water, which has itself been cooled by the refrigeration system
described above. The air is circulated through ducts, with a portion of fresh air added. There is
4
5. therefore a pre-heater, because the outside air may be below zero and will therefore freeze the
water in the cooling coil. A humidifier and various filters have also been added in figure 3.
Putting together the entire system
There are many variations on the basic design sketched in this article. Most refinements are to
save energy. The ratio of recycled air to fresh air can be increased when the outside air has, by
chance, the right water content and temperature to push the room climate in the right
direction. This is called enthalpy control, to make common sense seem scientific. The heat
generated in the coolant condenser can be re-used in the heater, fed by recirculating hot water.
The amount of air circulating in the system is vastly more than that required for the inhabitants
to breath, to avoid carbon dioxide narcosis and to avoid smelling each other. Air is mainly
used to carry heat and moisture to all corners of the building. Since the heat capacity of air is
rather small, quite large amounts are needed to ensure the uniformity of temperature that is
required by the specification. Here is another example of the danger of specifying without
adequate understanding. If the building is old and uninsulated the heat loss through the outer
walls will force a large air circulation, which will in turn require large ducts or make a lot of
noise. A leaky building requires considerable moisture added in winter. The RH of the air
leaving the humidifier will then be rather high, with a risk that pathological microorganisms
will thrive in remote corners of the ducts. Fitting air conditioning into existing buildings is not
easy.
Some refinements to the basic system compensate for the different heat requirements of
different rooms in the building. Figure 4 (next page) shows a complete system, with two
details that have not been mentioned yet: the outer zone, which loses more heat in winter, has
radiators to supplement the heat supply through the air conditioning. The inner zone has, in
this example, an archive room that is not much used and so is cooler, and drier, than the rooms
with people, computers and coffee machines. To keep the climate uniform throughout the
building there is a little local heater and humidifier placed just before the air reaches the room.
The main air supply is kept a little too cold and a little too dry. Any one of these many local
humidifiers can give trouble, with rapid over-humidification of the room. Again, here is a
dangerous detail that is provided by the engineer to protect himself against complaints that the
equipment does not achieve the standard required.
I hope that I have persuaded the reader who ever finds herself having to provide specifications
for the climate in a building, that there is more to making a sensible specification than stealing
numbers from the standards, most of which assume that the institution has piles of dollars and
its employees are too dumb to work out intelligent compromises that fit the needs of that
particular building and the materials and activities that it shelters.
5
6. Figure 4. An air conditioning system with variable fresh air mixer and dust and pollutant
filtration. Notice supplementary heating with radiators in the outer rooms and individual
mini heater and humidifier in the air stream to each room.
Tim Padfield, January 2000
6