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Bca j energy efficiency uq mech4460 lecture 2013


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The lecture was provided to 3-4 years students doing the Course Mech4460 - Energy & Environment at the University of Queensland. The aim was to introduce energy efficiency and energy efficiency regulations in the built Environment.

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Bca j energy efficiency uq mech4460 lecture 2013

  1. 1. BCA Section J Energy Efficiency Insert pictures across banner – picture height no greater than 3.5cm
  2. 2. Overview > > > > > > > > > > > > State Legislation & BCA changes in 2013 BCA Hierarchy Intent of BCA section J Definitions BCA DTS review of Building Fabric BCA DTS review of Glazing BCA DTS review of Building Sealing Mechanical Electrical Hydraulics Introduction to JV3 energy modeling Exercises
  3. 3. State Legislation Legislation varies in each state, the BCA Section J requirements where included for all new building designs from the 1st May 2005 for all states and territories in Australia. NT has still not legislated the use of BCA section J. The first major stringency increase of the BCA section J occurred in 2009 for the 2010+ versions. The 2013 version of the BCA Section J applies to all buildings designs from the 1st May 2013. Substantial changes in 2012 from 2013 are: > Internal glazing and glazing to non-conditioned spaces must be compliant > Fan motor power energy efficiency targets required a further 30% improvement > Direct electric heating prohibited in most applications > JV3 energy modeling approach is becoming more widely used due to the restriction on designs of the Deemed-to-Satisfy provisions
  4. 4. BCA Hierarchy We will cover this &…. An Intro to JV3 energy modeling
  5. 5. Intent of BCA section J To reduce Green House Gas Emissions “Buildings have the greatest potential to improve performance”
  6. 6. Intent of BCA section J > The objective of the BCA energy efficiency provisions is to reduce GHG emissions by reducing operational energy use of new buildings without reducing comfort and amenity > The extent of specific requirements will generally vary depending on the use of the building and the climate zone in which it is located > BCA requirements primarily address base building in relation to: > Heat flow-in and out of a building through the building envelope, and > Services-that use energy e.g. lighting, air-conditioning and hot water
  7. 7. Intent of BCA section J
  8. 8. Intent of BCA section J
  9. 9. Intent of BCA section J
  10. 10. Definitions Air-conditioning > A service that actively heats or cools a space in a building in order to provide a suitable environment for the building occupants Conditioned space > Space within a building where the environment is likely to be controlled by air-conditioning but does not include – > (a) a non-habitable room of a Class 2 building or a Class 4 building in which a heater with a capacity of not more than 1.2kW provides the air-conditioning; or > (b) a space in a Class 7, 8 or 9b building where the input power to an air-conditioning system is not more than 15 W/sqm
  11. 11. Definitions Envelope (Very Important) > Parts of the building’s fabric that separates a conditioned space from the exterior of the building or a non-conditioned space
  12. 12. Definitions Further Explanation of the Envelope Plant room ceiling is not required to be insulated as it is not part of the envelope Occupied space is required to have the ceiling insulated when below a plant room or non-conditioned space Plant Room Occupied space Occupied space
  13. 13. BCA DTS review of Building Fabric The adjacent table is an extract from the BCA. This table applies to roofs and ceilings The table specifies the minimum total averaged R-value for the construction
  14. 14. BCA DTS review of Building Fabric Walls (See J1.5) The table adjacent shows the calculations required to determine a total R-value for a particular construction. If there is a mixture of constructions across a façade the average total of these will determine the compliance of the façade.
  15. 15. BCA DTS review of Glazing (Part J2) Glazing -for the purposes of Section J2 means: “A transparent or translucent element and its supporting frame located in the external fabric of the building, and includes a window and the glazed part of a door“
  16. 16. Glazing Performance: “U” & “SHGC” The BCA J2 Provisions Consider: > Heat Conduction through glazing driven by a difference in temperatures… U Value > Solar Radiation through glazing into building…...Solar Heat Gain Coefficient (SHGC) Glazing performance is “whole of window” and includes framing. Can be obtained from A) manufacturer, B) or C) calculated.
  17. 17. BCA DTS review of Building sealing Part J3 Building Sealing Construction of roofs, ceilings, walls and any opening such as a window, door or the like, must be constructed to minimize air leakage. A perforated ceiling in this application may not comply with J3, even if there is insulation applied in compliance with J1.
  18. 18. Architecture: Energy Efficiency Cont. PART J3 BUILDING SEALING > J3.1 Intent > All openings within the building that allow escape of energy are to be considered and treated so as to reduce energy loss > J3.4 Windows and Doors > Requires seals to be fitted to doors, openable windows, etc. forming part of the external fabric of a habitable room > Seals on louvre doors, louvre windows or other such openings, are required.
  19. 19. Architecture: Energy Efficiency Cont. > Building envelope to be fully sealed against air leakage – future consideration of making building leakage testing mandatory as in the UK > Draft protection devices to be fitted to the bottom edges of external swing doors > Provision for airlocks, apply to any entrance J3.5 Exhaust Fans > Requires an exhaust fan to be fitted with a sealing device such as a self-closing damper J3.7 Evaporative Coolers > Require an evaporative cooler to be fitted with a self-closing damper.
  20. 20. Mechanical: Energy Efficiency PART J5 AIR-CONDITIONING & VENTILATION SYSTEMS > Looks at system design and control, Fan and pump energy and the allowances for outside air. > J5.2 Air-conditioning and Ventilation Systems  The air conditioning of a Class 3 sole occupancy unit must cease if an external door to a balcony, patio or courtyard is left open.  Minimum Pump and fan Power efficiency requirements > Variable air flow systems to have VSDs > Economy cycle threshold lowered and exemptions > The over-supply permitted of outside air has been reduced is 120%. NOTE conflict with the GBCA 150% OA increase to get minimum green points in IEQ-1 > Systems to have fully insulated ducting on supply air side > Return air ducting in ceiling void of a conditioned space does not need insulation
  21. 21. Mechanical: Energy Efficiency Cont. > J5.4 Heating and Cooling Systems > Separate pump allowances for chilled water, condenser water and heating water. > Minimum threshold for variable speed pumps 3 kW – i.e. below 3kW pump power no VSD is required > Provisions for heating a space, the requirements for a heating systems to be other than a direct electric heating. Also, oil is limited to locations without reticulated gas. > Fixed space heating appliances installed outdoors must have automatic controls. > Insulation on duct and pipe services must be to AS/NZS 4859.1 and is specified in terms of material R-value. Refrigerant and steam piping is included.
  22. 22. Electrical: Energy Efficiency > J6.2 Interior Artificial Lighting > Amended so that (a) now applies in sole-occupancy units in a Class 2 building or a Class 4 part while (b) applies to all other buildings > Consequently, Table J6.2a has been removed and other tables amended > Class 2 and Class 4 part are now required to meet 5star energy rating > Some illumination power densities have been increased while others reduced. E.g. Laboratory is 12W/m² instead of 15W/m² > As part of the increased energy efficiency stringency, the exception for small shops in (b)(i) has been removed > Internal light fitting transformers or ballasts to be electronic type only 10 July 2010
  23. 23. Electrical: Energy Efficiency Cont. > J6.3 & J6.4 Interior Artificial Lighting and Power Control > Light switches for single lighting zones such as in an auditorium, theatre, swimming pool or sporting stadium is allowed to be a single switch, all other areas of buildings are to have zone controlled lighting. > The allowable area of a lighting zone controlled by one switch is been limited to 250 m2 in Class 5 (office) buildings and Class 8 laboratories > 95% of buildings other than class 2, 3 and parts of class 4, of more than 250m² shall be controlled by a time switch or occupancy sensor. > J6.4(a) Decorative and Display lighting shall be separately switched by time switch if the lighting exceeds 1KW. > All lighting systems have maximum power density values that are specified in the BCA.
  24. 24. Hydraulic and Mechanical: Energy Efficiency PART J7 HW SUPPLY & SWIMMING POOL & SPA POOL PLANT > Provisions requiring swimming pools and spa pools to use energy efficiently and also to not be heated by electricity. > Additionally, a time switch must be provided for controlling the circulation pump and heated swimming / spa pools must be covered when not being used.
  25. 25. All Discipline: Energy Efficiency PART J8 ACCESS FOR MAINTENANCE & FACILITIES FOR MONITORING > J8.3 Facilities for Energy Monitoring > Provision of a means of measuring the energy use of the various services. > Buildings over 2000m2 are to have individual metering for Lighting, power, HVAC, hydraulics and other major systems.
  26. 26. JV3 - Energy Modeling Comparing the Method of Assessment A – Architecture B – Building Services C – Compliance
  27. 27. JV3 - Energy Modeling Energy models form the IES-VE software
  28. 28. JV3 - Energy Modeling Results tables 1. Results tables – what is sometimes presented – what should be presented Building Services – Mech, Elec Hydra Annual Energy Consumption (MWh) Time Period Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total Reference Proposed Building Building 78.1803 51.3554 69.8147 46.2047 70.0583 43.1365 59.9688 34.5594 54.5476 30.4192 45.5895 27.8947 46.0715 28.8246 49.1038 28.8666 54.0059 28.61 62.1816 34.7663 68.5068 41.5262 74.6208 46.9102 732.6497 443.0738 OR Baseline Baseline Proposed Baseline Proposed Proposed Lighting Equipment Heating, cooling, and Ventilation - packaged unit Lifts Hot Water Total - MWh Conversion to MJ - factor Total MJ Conversion to Kg CO2/yr - factor MWh 1.5222 1.4642 MWh 1.5222 1.4642 MWh 1.5222 1.4642 2.4568 0 1.3705 6.8137 3.6 24.52932 0.0548 2.4568 0 1.3705 6.8137 3.6 24.52932 0.0548 2.2892 0 1.3705 6.6461 3.6 23.92596 0.0548 Kg CO2/yr Assessed area (m2) kWh/m2 1.344 60 114 1.344 60 114 1.311 60 111
  29. 29. Energy Modeling – of building massing
  30. 30. Energy Modeling – of building massing
  31. 31. Energy Modeling – of building massing
  32. 32. Self learning Exercises 1. In your own words, describe the meaning of R-value? 2. What is the difference between R-value and Total R-value? 3. What wall construction that forms part of the envelope would not require additional insulation? 4. What needs to be considered when selecting thermal insulation? 5. What needs to be considered when installing reflective insulation? 6. What needs to be considered when installing bulk insulation? 7. In your own words describe the meaning of U-value? 8. What is the difference between SHGC – Solar Heat Gain Coefficient and the SC - Shading co-efficient? 9. Determine why HVAC systems have different zoning – how should these zones be arranged? 10. Lighting systems such and LED and compact fluorescence are more efficient – can they be used in all situations? 11. Why would climate zones 1 & 2 be allowed to use direct electric heating?
  33. 33. Self learning Exercises Some Heat load calculations in a Space 1. From the data provide, calculate the grand total heat load in the room
  34. 34. Self learning Exercises Some Heat load calculations in a Space 1. Room is a Cube with a flat roof – 4m x 4m x 3m high – all elements U-value of 0.5 W/m2 K 2. Room contains 2 people – 75W sensible & 55W Latent 3. Room contains 1 flat screen TV (350W), Computer (200W) and modem (5W) 4. Room has one large window in the north facing wall – 2m wide x 1.8m high and no shading devices – standard domestic single glazed window 5. Outside air temperature is 37 C, inside is to be kept at 24 C 6. Room has 2-12W LED lights 7. Infiltration of air into the space occurs at a rate of 0.25 air changes per hour Calculate the grand total heat gain in the space How do you reduce this heat gain? What are some ideas?