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;

Recommiting ready for summer

This is the time of year when a number of our water and energy saving measures need to be reinstated for summer. Doing so involves a recommitment to these actions and, for some, a small degree of maintenance.

So our 'action' for November was not a new action but a recommitment to many previous actions, and in some ways it was the hardest 'action' I have committed to in the three and a half years we have been doing this. Here we go again. Does it never end?? I think life at home with two small children may be shaping that reaction! It is more difficult also, in my experience, to do something again, when it is no longer new and interesting. This is particularly so when it is restarting something that I have failed to continue on with as I originally intended.

After a week of that summer heat smell in the air it was time for Tyson to unroll shadecloths around the house. 

So far we have no new ones this year, but are reinstating all of those from previous years.

One of those along the driveway remains furled as it broke its moorings in winter storms and needs a more permanent hook attached to the bricks to keep it secure. The shock cord for another had also worn through and the rear courtyard shade is definitely not still using the original ocky straps from six summers ago! Overall, though, the shades and their fastenings are holding up well.

The grey water wheelie bin has been brought back into service. I discovered that I cannot get it over the laundry threshold (or if I do I spill quite a lot in the effort) so Tyson sourced some grey water hose to create an extension out the door ($20 for ten metres).

The door obviously doesn't lock like this, but a chock to stop it sliding open any further makes us reasonably confident to leave the washing machine running with its outlet pipe through the back door when we go out.

The original tap connection on the bin had also given us grief last summer, periodically leaking or unwinding itself and falling off, so Tyson purchased a new tank outlet connector (about $8). 

This required sanding the hole for the pipe slightly larger to make it fit, but so far has been a very successful adaptation. The hose we attach to the tap got little holes drilled along it some time last summer to create a drip system for better coverage.

We also put the tubs back into our shower and have grey water on hand again for toilet flushing. This stopped not on account of winter bringing rain, but because somewhere midyear, in late pregnancy, a string of minor ailments over three months had me desperate to change anything that might be contributing and grey water standing uncovered in our bathroom seemed a potential source of winter sniffles. And then we had a baby and I couldn't be bothered with even the small additional effort of gathering and flushing grey water.

The basin in our kitchen sink comes and goes. We are making another attempt at it this summer. Periodically we get fed up with it not getting emptied outside, or getting too dirty, and it is abandoned. Hence it was definitely one of the actions for me that was a recommit, not a routine, as we approach summer.

Costs and times for these actions are detailed in the links above to where I wrote about them originally. Aside from fifteen minutes here or there for maintenance, recommitting doesn't add more time than the original commitment. 

It is much easier, though, to continue with actions that are simply ongoing than to pick up these summer-oriented actions at the end of spring each year. Part of me is tired and thinks oh lets just water with a hose/ flush the toilet/ blast the aircon like everyone else. It was 37 degrees here yesterday (Celsius - that's 100 degrees Fahrenheit, for you in other lands - what some here refer to as 'the old hundred') and the heat made me grumpy. I am home full time with a three year old and a four month old. I get grumpy plenty quick enough all on my own - I don't need any extra grumpifiers! But then... the house kept quite cool most of the day, and when we eventually turned the aircon on (we are not ascetics, after all) I was still grumpy about the heat, so I might as well be sustainable and grumpy. When I look at my reaction, it is being trapped inside that bothers me, and aircon or passive cooling both have that same result. Its grey and raining today... some respite for me to think creatively about ways to get outside as much as possible through summer so I don't get that terrible trapped feeling. Any ideas?

What are you needing to recommit to at present?

Just when you think you can't shade anymore...

When I wrote in December about our summer shading system I thought we had shaded everything we could reasonably manage. But as it got hotter we found more exposed areas that could be protected and added:

additional dense (90% block-out) shade cloth to patch a gap in the rear (southwest) courtyard shading,

 

on very hot days, a towel inside the (northeast) bathroom window, which has no eaves,

on very hot days, an old painting canvas inside the (southwest) laundry glass sliding doors, which get blasted with afternoon sun,

 an old woollen wall hanging on the southwest wall outside Eva's bedroom, and

three towels left on the clothesline all summer along the northwest living area wall.

These also make a good cubby.

Initial Time: Shade cloth: fifteen minutes to bend hooks and hang the cloth; wall hanging:five minutes to put a hook in; towels: 30 seconds each to hang; paint canvas: 30 seconds to balance in place on the grey water bin.

Initial Cost:$20 for shade cloth, zero for towels, paint canvas or wall hanging (which was being thrown out by a family member)

Ongoing time or cost commitment: One or two minutes every week or two to readjust the rear shadecloth as it slips a bit in windy weather; 30 seconds each on hot days to put up the inside towel and paint canvas; probably about ten minutes at the end of summer to pack away for cooler weather.

Impact:A southwest facing vertical surface in Perth in summer receives approximately 3kWh of energy per square metre per day. If the surface is unshaded transparent glass, almost all this energy gets inside the house as heat. The additional shading to our rear courtyard gives 90% shading to about 3 square metres of glass, reducing the amount of heat entering our living area in summer by approximately 8.1 kWh per day. We have a 300% efficient reverse cycle air conditioner in the living area which would use 2.7 kWh of energy to remove 8.1 kWh of heat.So, by shading instead of turning on the airconditioner most days, we are saving 2.7 units of electricity per hot day just with this one area of shade cloth. Put another way, we start to get ahead of the $20 spent on shade cloth on the 27th day of not turning on the aircon. (Thanks Tyson for knowing the numbers!)

In less precise terms, I estimate that this summer it has generally been the third day in any heat wave before we turn on the airconditioner, and last summer I think it was more often the second day. I consider a heat wave to be when the temperature stays at the mid thirties or higher for more than one day. Our airconditioner rarely runs on days with temperatures up to the low thirties (celsius!).

Calculations for the towels and wool hanging shading wall areas, and the paint canvas inside vertical blinds, are more difficult, but we notice that these rooms heat up slower. (In terms of impact, one woolen wall hanging also has a new purpose in life and has been saved from landfill, at least for a while.

Our recent power bill for 22 Dec to 24 Feb shows an average electricity usage of 8 units a day (530 units total), a very very small reduction on the same period last year (10 units less over two months). Most of the past year our average usage has been around 6 units a day, so summer is still presenting the biggest challenges for reducing electricity use at our house. It was the fourth hottest summer in Perth ever recorded (since 1897) and I was going to excuse our tiny reduction by pointing to this fact - until I discovered two of the other three hottest summers were 2009-2010 and 2010-2011. (Its hard to deny climate change when three of the four hottest summers here in the last 115 years were the last three consecutive years... the other was 1997-98). So my alternate excuse for our electricity usage not reducing compared with last summer is that this year I am pregnant and feel hot quicker!

To put our usage in some perspective, however, Synergy (our local electricity supplier) estimates the average household electricity use in WA's southwest grid is 6250 kWh per year (over 17 units per day). Our household's 2011 usage was 2452 kWh (6.7 units per day). We are living a perfectly comfortable existence on that amount of energy.

Shading the house for summer

The arrival of summer means time to roll out the window shades all around the house. Three stay up all year, one is stored away, and another is rolled up and tied on the roof through cooler weather.

east corner

west corner

We installed three new shades this year, as necessary pruning in the front yard had left some of our northeast windows too exposed to morning sun. The most significant of these is a shadecloth wrapping the exposed east corner of the house. We can't quite believe how much cooler the whole house is for reducing the morning sun on this east corner.

We also put a large plant outside the piece of southwest wall that is the head of Eva's bed, to cut the baking sun and try and keep her bedroom a little cooler. The plant doesn't like all that sun so we may need to reconsider how we shade that spot through summer.

Initial Time: Installing the threenew shades took about two hours. Rolling out or reinstalling last year's shades took about twenty minutes.

Initial Cost: Tyson spent about $20 on more shadecloth, timber and shade cloth clips.

Ongoing time or cost commitment: Nothing to do until we roll them up again in late April, except for the two smaller ones that blow in the wind and sometimes need to be pulled back off the roof.

Impact: So far no hot days have required the airconditioner, except for one when we were all sick and normal cooling was not enough. The office, now in the east corner of the house following a room shuffle, hasn't even needed a fan yet.

Past blog entries about shading can be found in December 2010 and December 2009. Note that the tarpaulin shown in the 2010 entry tore in half in strong wind as air couldn't escape through it, so we now only use permeable shade cloth to maintain air movement. We've had a couple of questions about how we fasten the shade cloths, so below are a series of photos to illustrate the detail of the operation.

 

timber on the first shade we put up is starting to weather after four years