BCA Section J Energy Efficiency Insert pictures across banner – picture height no greater than 3.5cm

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

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

BCA Hierarchy

We will cover this &….

An Intro to JV3 energy modeling

Intent of BCA section J

To reduce Green House

Gas Emissions

“Buildings have the greatest potential to improve performance”

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

Intent of BCA section J

Intent of BCA section J

Intent of BCA section J

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

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

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

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

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.

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“

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) www.wers.net/commercial/certified-products

or C) calculated.

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.

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.

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.

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

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.

10 July 2010

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 5-star 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

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.

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.

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.

Comparing the Method of Assessment

A – Architecture B – Building Services C – Compliance

JV3 - Energy Modeling

Energy models form the IES-VE software JV3 - Energy Modeling

Results tables 1. Results tables – what is sometimes presented – what should be presented

Annual Energy Consumption (MWh) Time Period

Reference Building

Proposed Building

Jan 78.1803 51.3554 Feb 69.8147 46.2047 Mar 70.0583 43.1365 Apr 59.9688 34.5594 May 54.5476 30.4192 Jun 45.5895 27.8947 Jul 46.0715 28.8246 Aug 49.1038 28.8666 Sep 54.0059 28.61 Oct 62.1816 34.7663 Nov 68.5068 41.5262 Dec 74.6208 46.9102

Total 732.6497 443.0738

Building Baseline Baseline Proposed Services – Mech, Elec Hydra Baseline Proposed Proposed MWh MWh MWh Lighting 1.5222 1.5222 1.5222 Equipment 1.4642 1.4642 1.4642 Heating, cooling, and Ventilation - packaged unit 2.4568 2.4568 2.2892 Lifts 0 0 0 Hot Water 1.3705 1.3705 1.3705 Total - MWh 6.8137 6.8137 6.6461 Conversion to MJ - factor 3.6 3.6 3.6 Total MJ 24.52932 24.52932 23.92596 Conversion to Kg CO2/yr - factor 0.0548 0.0548 0.0548

Kg CO2/yr 1.344 1.344 1.311 Assessed area (m2) 60 60 60 kWh/m2 114 114 111

OR

JV3 - Energy Modeling

Energy Modeling – of building massing

Energy Modeling – of building massing

Energy Modeling – of building massing

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 Co-

efficient 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?

Self learning Exercises

Some Heat load calculations in a Space 1. From the data provide, calculate the grand total heat load in the

room

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?