Sorting out a homes cooling system can easily become information overload if you haven’t had time to research the systems that are out there and what might be best for your situation. So here are some things to keep in mind when it comes to keeping cool this summer.
Danielle King is the Founder and Director of Green Moves Australia, a private company created to provide householders with a selection of sustainability services designed to help minimise a home’s running costs while reducing the environmental footprint. Danielle has an MBA, Dip. Management and Certificate IV in Training and Assessment. She is also a fully qualified Home Sustainability Assessor listed with Sustainability Victoria and ABSA, and is BDAV Accredited.
Always use passive cooling systems. They cost nothing to run and when used properly can have a significant effect on keeping a home cool. Passive systems include:
• Using external shading, particularly to north and west windows to keep sun of the windows and walls,
• Opening windows to allow for natural ventilation,
• Using internal reflective blinds (such as renshade or inflector) to reflect the heat back out
• Having heat reflective window films on glazing (such as enerlogic)
• Or using thermally lined close fitting curtains with pelmets or roman blinds to keep the sun out.
Note that external shading and natural ventilation is the most effective. Another way to get cool air into the home is by placing water (eg pools, ponds) near a window on the prevailing breeze side (in Melbourne that’s generally to the north or south).
If you’re renovating or building and have some flexibility, ensure the placement of windows and opening type facilitates catching the cooler southerly breezes in summer and allows for venting hot air out of the home during those hot spells. Casement type windows are great at directing breezes into the home as they can be angled to suit wind direction. Placing a closeable exhaust fan at a high point of the ceiling in the main living space, or at the top of a stair case is also a simple and cost effective method to exhaust hot air from the home.
Then there’s the “Active” systems. Active cooling systems are those that use energy (and cost money) to run. There are several types out there and here’s a brief summary of them, in order of cheapest to run;
Fans – cheapest at around 1.5 cents per hour
Inverter (heat pump) reverse cycle air conditioner’s
Refrigerated air conditioning
Ducted systems (refrigerated) can cost up to $2.50 per hour depending on the system.
Many don’t like the look of ceiling fans, but there are some very cool fans around these days. We particularly like the Aeratron which won a clean tech award earlier this year for being quiet and highly energy efficient. See aeratron.org for more information. There’s also the Haiku from ‘Big Ass Fans’ which is also very nice to look at and efficient. See bigassfans.com for more information on this one. Dyson also has a very trendy (but expensive) range of portable fans.
Whole house systems – If you have, or are going to install a whole home ducted heating or cooling systems, ensure it can be zoned at minimum to living areas and bedroom areas and ensure you can close off those areas when the system is on. Place the thermostat in an appropriate place (not the hallway, in the room most used) and get the most energy efficient model you can.
A note on Ducting. This is often forgotten and the cheapest option is usually installed. However uninsulated and badly sealed ducting can account for up to 50% of the running cost of a ducted system. We recently came across a local company called Coolro Air that had a well insulated and sealed ducting system called Ductair Energy Smart. We were impressed with the independent testing results and the extensive warranty and suggest that anyone looking to replace or install ducted systems to look seriously at this system. It is very energy efficient and has the best warranty we’ve seen.
So if you want to keep cool without blowing the budget this summer, first shade, then turn on the fan, then lastly the air-conditioner. And remember, run your air-conditioner with the fan, it won’t have to work so hard (saving energy) and will keep you cooler!
- A breath of fresh air (buildexpo.wordpress.com)
- Frequently Asked Questions on Portable Air Conditioners (airconditioningspecialist.wordpress.com)
- Make Your Home Energy Efficient To Reduce Your Energy Bills (orlandorealtyconsultants.com)