Archives for February 2011

People who visit our home during hot and cold weather often comment on the comfortable temperature inside it.  Well it is not because we run the air conditioner or heater 24×7, far from it.  It is more like a few small actions that we took and continue to practice each day.

Firstly, we took the time to check our roof insulation levels.  It is paper pulp type insulation and there is lot of it up there.  I made sure that it was level throughout the roof space and that there were no gapes in the coverage.  If it was too high in one area I just moved it with a flat board to another lower area.  Job sorted and at no cost to me.

When we first moved in we changed over the light fittings to more energy efficient ones, and tried to minimize the number of holes that we cut into the ceiling.  Holes mean heat loss on a cold night or heat ingress from the roof cavity during hot days.  We repeated this philosophy when we planned and built our kitchen renovation last year.  We actually eliminated all the holes in the roof in what was 3 separate rooms.  The kitchen is much warmer in winter now, and cooler in summer because of it.  We also fitted ceiling fans at both end for additional air movement and in every other room as well.

Then it was on to weather proofing or draft proofing to ensure that there could be minimal heat loss from our home.  It also prevents heat ingress during summer.  Drafts and gaps around the doors and windows can account for 25-50% of your homes heat loss.  It was quite an easy thing to remedy as the window frames were all in good condition with no gaps and we only needed to consider two of the three outward facing doors as the glass sliding door was already draft proofed.  To close up the gaping spaces between the door jams and the doors, I used foam strips from the hardware store and ran it all around the frame on both doors.  Then I installed a draft stopper at the bottom of each one which eliminates the gap underneath each door as it closes.  Total cost was about $50 for both doors.  I tested each door with the smoke from an incense stick to ensure that there were no drafts.

 With the doors and window gaps taken care of, there was the window glass to consider.    Windows are a bit of a mixed blessing.  You can let a cool breeze flow through at the end of a cool day and it can let out pollutants out.  However, did you know that glass can be the cause of around 10-20% heat loss in winter and around 25-35% heat gain in summer.  Not a very good insulator at all.  Now double or triple glazing is an expensive fix to this problem and prevents most of the heat loss/gain with a pocket of air between two panes of glass, and is well worth the capital expense over the longer term.  However we did not choose to replace every single window with double glazing because there is a cheaper alternative.  As we have sliding windows in an aluminium frame (more heat loss through the frame) I could not place bubble wrap up (acts like a simple double glaze) against the windows as we still wanted to open them.   In summer we pull down heavy canvas awnings to the ground to prevent direct sunlight from entering the house from the north, and the east and westerly windows are underneath verandas.  This stops most of the heat gain.  In winter we roll the awnings all the way up to let in maximum light and heat causing a mini greenhouse effect.

Also with the aid of curtains, we also cover the windows on hot days and cold nights to stop heat transfer either way.  In both seasons we zone the house using internal doors and usually stay in the most comfortable rooms, south in summer and north in winter.  By closing off unoccupied rooms, you avert cooling or heating this extra space.  Why would you heat an empty room?  Kind of like leaving the light on when it is empty, same principle.

We have a ceiling fan in each room to assist with moving the air around in both summer and winter, and in emergencies (days over 35C) we use the air-conditioner for a few hours until the room cools down.  We have a two natural gas wall heaters for winter.

All of these active home management principles help us to maximize our heating/cooling expenditure.  Other things we practice is using only one of the two wall heaters at a time an only for two hours a day in winter and off at bed time.  Extra blankets are a much cheaper alternative than leaving the gas heater on all night.  If anyone is cold during the day, then we tell them to put a jumper (sweater) on to warm up.  With the draft proofing and active home management, our home stays a nice 20-25C in summer and 18-20C in winter with very low energy bills.  All common sense really in a world that seems to be lacking some.

Finally, size really does matter!  Larger, modern homes have a greater internal space which uses more fuel to heat/cool it, with little in the way of internal door to zone areas off from the rest of the home.  They also have to use central heating to keep it warm in winter and big split system air-cons to keep it cool in summer.  Basically they are unbearable without these devices.  The larger the home, the more energy required to control the comfort levels.

So by having a well designed or thoughtfully retrofitted smaller home, and by using passive design or active home management, you can keep your energy bills way, way down.

Behavioral change costs nothing at all!