Transcript
TIPS FOR ENERGY SAVING IN OLD AND NEW HOMES
NOTE: The following information is intended as a rough guide only to improving efficiency of home energy use, and hence to reducing greenhouse gas emissions. Users are advised to obtain professional advice for all renovation and technical tasks in their home, for their own safety and to ensure the structural integrity of buildings.
Ten most cost-effective steps, taken in any order: 1. 2. 3. 4. 5. 6. 7.
Apply passive design principles in siting and later Replace old lights with LEDs Stop draughts Improve insulation Upgrade windows Use energy-efficient appliances Install reverse-cycle air-conditioning, for heating and cooling 8. Use solar or heat-pump systems for water heating 9. Monitor and control energy use 10. Solar panels to generate your electricity. Adapted for Ballarat, from research in Beyond Zero Emissions Buildings Plan - See BZE book: “Energy Freedom House”
– available to purchase from http://bze.org.au/product/energy-freedom-home-book/
Renovators often overlook measures which improve energy efficiency Category Percent missed Energy saving ‘opportunities missed opportunity (%) Insulation
No insulation fitted to suspended floors No insulation fitted to external walls
72 60
Incomplete ceiling insulation (Gaps)
30
No insulation under roof tiles
30
Draught proofing
Door seals missing No dampers on exhaust fans
30 10
Windows
No chimney dampers fitted Areas of unprotected western windows Inefficient new windows/ frames
5 20 15
Inefficient lighting choices
50
Lighting
[But – be sure to check the costs and benefits of each option] From Victorian Household Energy Report 2016. http://www.sustainability.vic.gov.au/-/media/resources/documents/services-andadvice/households/energyefficiency/rse014-households-energy-report_web.pdf?la=en
See also: Australia’s guide to building, buying or renovating a home http://www.yourhome.gov.au/
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Windows • •
• • •
Use closely woven, close-fitting curtains or blinds Ensure there’s a snug fit on both sides of the window and at the top of the curtain to stop warm air from moving down behind the curtain and cooling Install boxed pelmets or solid barriers above the curtain rail, or position the curtain within the window space Use curtain tracks that provide a return of curtain to the wall to create a seal Close curtains or blinds when you have the heating on, especially at night – by leaving curtains or blinds open, you're wasting money and energy
To keep the heat in, consider • • • •
Internal window coverings Double glazing Secondary glazing Material used for window frames
To keep the heat out in summer, consider • •
Shading external windows Glass coatings and films
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Daily behaviour to save energy: 1. Dress for the weather – in winter, wear extra layers inside and lower your heating thermostat. By setting your heating thermostat between 18-20°C, you can decrease your running costs by 10% or more. In summer, wear lighter clothing and keep your air conditioner’s thermostat between 24°C – 26°C. 2. Only heat or cool and light rooms you are using. Where possible, zone your lighting and ducted heating or cooling and close off doors to unoccupied rooms. Set your thermostat with care: With heating, every degree above 18oC adds 10% to your bill; with cooling, every degree below 26oC adds 10% to your bill. 3. By washing your clothes in cold water and drying on a line or rack, you can save up to $100* a year. 4. Compare your electricity suppliers to check you are getting the best deal on your rates at switchon.vic.gov.au.
Appliances - how to save energy 1. Your fridge runs 24 hours a day 365 days a year. This adds up and makes it the most expensive appliance to run. Make sure that the door seal is tight and free from gaps so cold air doesn't escape. If you have a second fridge, give it a winter break - just turn it on when you need it. Reduce fridge contents to a minimum, but keep your freezer full 2. Consider using energy efficient light globes, such as LEDs as an alternative to general lighting and avoid halogen downlights 3. Switch off appliances not in use, at the wall. The cost of appliances which are switched on and not being used (on standby) can add over $100 on your annual power bill. 4. Have a free standby power controller installed to save money and electricity. Standby power controllers automatically cut off power to your electronic devices when you switch them to stand-by mode by pressing the on/off button on your remote control. For a list of accredited installers go to www.veet.vic.gov.au. 5. When buying, get the highest star rating practicable. More information about this: http://www.sustainability.vic.gov.au/services-and-advice/households/energyefficiency/toolbox/how-to/keep-heat-in
Air losses though ceilings can cause high energy bills - so ‘Seal your ceiling‘ Hot air from heaters rises, so any leaks through the ceiling result in heat loss and higher heating costs. Common cause of loss Simple solutions Poor insulation above ceiling Increase thickness to R6 or higher Unsealed exhaust fans Install effective draft stoppers Unsealed down-lights Install LED bulbs and Seal vents Skylights with vents or leaks Seal leaks and double glaze Old air vents that are now not needed Seal old vents Unsealed joints between walls, floor and ceiling Seal and insulate all wall corners
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UNDERSTAND THE HEAT TRANSFER QUALITIES OF ALL YOUR HOUSING MATERIALS
Table of R-values and U-values – For common housing materials/ components R Value is the Thermal Resistance – e.g. used for ceiling Insulation. The higher the R value the better. U Value is Heat Transfer value – e.g. used in window materials. The lower the U value the better.
Wall materials
Floor, roof, ceiling & window materials
R value
U value
Weather board wall Brick veneer wall Brick veneer with 75mm batt Brick veneer w 10mm aerogel blanket Cavity double brick wall Cavity Double brick wall with lose-fill or polyurethane insulation Solid brick wall (230 mm) Solid brick wall (300mm) Solid stone wall (300mm thick) Solid stone wall (300mm thick) with plasterboard & sarking inside Solid concrete wall (200 mm thick)
0.55 0.51 2.0 1.2 0.53 1.4
1.8 1.86 0.5 0.83 1.88 0.71
0.44 1.5 0.4 1.5
2.27 0.66 2.8 0.66
0.30
3.33
Aerated concrete wall (100mm block) Aerated concrete wall (200mm block) Mud brick wall (300mm block) Plaster board 10mm thick Solid wooden door (12 mm thick)
0.78 1.54 0.40 0.06
1.28 0.65 2.5 16.6 3.0
Floorboards (19mm) plus carpet & underlay Sarking with 200mm static airgap Concrete slab 150mm thick Glasswool batts (175mm thick) Aerated blanket (10 mm thick) Tiled roof (tiles alone) Metal roof (alone) Single pane clear glass (3mm) *Single Perspex pane (3mm) Single pane Low E glass Double glazing with 16 mm air gap D-glazed unit with Low E coating D-glazed unit with Low E coating and 16mm argon-filled gap Centre of framed window pane data *Aluminium ‘frame unit’ single pane *Alum. ‘frame unit’ D-glazed 12mm gap *Wood/PVC frame unit single pane *Wood/PVC frame unit D-glazed 12mm
Data mainly from Marsh AD (2001) Sustainability and the old Australian house. * Data from other sources. The U Value is the Inverse of R value. Divide 1 by either the R or U value to convert to the other unit. For instance a substance with an R-Value of 2 has a U-Value of 0.5 = (1 divided by 2)
Heat loss through window (for e.g.) is calculated by: Watts = Area x U value x Temp Difference (diff between outside & inside temperature
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R value
U value
0.12 1.1 0.104 3.5 0.7 0.02 0.01 - 0.18 0.19 0.27 0.38 0.55 0.62 0.14 0.28 0.18 0.4
8.33 0.9 9.6 0.28 1.42 43.4 100 + 5.4 5.2 3.7 2.6 1.6 1.6 7 3.5 5.5 2.5
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