31 May 2014

Winterise the house

Winter starts tomorrow (although it was cold enough for winter here today). Although our energy-saving efforts have been more directed towards passive cooling in summer, we do a few things to reduce our energy use for heating in winter too. Like wearing warm clothes and ugg boots at home.

That's sheepskin boots all furry on the inside, for those in other parts of the world

May has been the month to roll up the summer shades all around the house. We get so used to them that it has taken several goes, as we kept noticing one or two more we've forgotten. We added even more shades this summer - a big one along the southwest wall (Eva's bedroom) and a much improved one on the eaveless northeast bathroom window. 

Eva & Tyson building the new shade last November

As a result of all our passive cooling efforts, we only turned the airconditioner on for four hours all summer (half of that on the morning when it was already 39°C at 9am).

For winter we lay down an extra carpet to more than double the covered floor space in the living area. This gets morning winter sun and is a lovely place to play. 

We don't have a dryer. We line-dry our clothes outside any day we can, and use an indoor clothes rack on wet days. This gets sat where sun comes inside, or in the bathroom with a pedestal fan blowing on it. 

Our hot water system has its outdoor pipe insulated so that we don't lose so much heat into the cold winter air. I try to use the tap closest to the hot water system (laundry tap) when running warm water for things like wipes, to reduce how much water and gas is wasted getting just a bit of warm for what I need.

When I am working from home, I wear ugg boots and wrap in a blanket rather than having a heater in the office.   

Eva pretending to be me at work - note the full-body blanket wrap, my characteristic work attire

Perth has a mild winter, but can have comparatively cold nights. We often open all the windows during the day to get warm midday air inside. On really nice days, we put the bathroom and kitchen extractor fans on to draw in the warm outdoor air.

Around sunset, we close all the windows and blinds, especially if the oven is on, so we can trap daytime and cooking heat in the house overnight. We pull the heat barrier curtain to separate the laundry from the living spaces we are trying to keep warm. We have weather sealed the front door to keep drafts out. On really cold evenings we sometimes run a heater for a couple of hours after dark. Very occasionally. When its the reverse-cycle air-conditioner we set it to 19°C.

The children take a heat-pack or hot water bottle to bed on cold nights, as well as wearing warm jarmies and socks and having good thick covers. We don't have any heating running overnight.

I've written about most of these measures before, and a lot of them are pretty basic common sense. I recognise that in some colder climates, these measures would not be enough to keep you warm - but they might be a good start. I also acknowledge that I prefer a cooler house, and some of our friends do come to evening events at our home with coats to wear inside. They are quite happy with that arrangement.

Don't let the cold stop you jumping on the trampoline (fully rugged of course)

Initial Time: half hour to take up the summer shades; five minutes laying the winter carpet down

Initial Cost: zero

Ongoing time or cost commitment: five or ten minutes a day opening and closing blinds etc; ten minutes per washing load pegging it out. As our winterising measures save energy, they also save us money.

Impact: We barely use heating in winter. We maybe turn a heater on 10-15 days in the year, and then only for an hour or two. If we were to run our 2.5kW reverse-cycle airconditioner as a heater for 1-2 hours every night through winter (still a lot less than many people in Perth), we would use approximately 230kWhrs of energy (230 'units'). If we turn it on only 15 times, we use approximately 37.5kWhrs. That is a saving of about 158kg of carbon dioxide.

A reasonably efficient clothes dryer uses around 3.5kWhrs per load. A pedestal fan can run for 20 hours before it reaches 1kWhr, but usually about twelve hours is enough to dry a washing load. Even at 20 hours, that's a saving of around 2kg of carbon dioxide per washing load.

[In WA at present, each kWhr of electricity uses 0.82kg of carbon dioxide, down from 0.992 four years ago. NSW & Qld levels are about the same; Vic is much higher (heavy reliance on brown coal), SA is lower (lots of wind farms); Tas is nominal (mostly hydropower)]

For blog readers in the northern hemisphere about to step into summer (bless you, I don't know who you are but apparently lots of you are reading this blog!): here's a bunch of posts about passive cooling measures: recommitting for summer; various temporary measures; pelmets; shading; more shading; shading again; grapevines for shading; shed vents and more shading; heat barrier curtain; bits & pieces;