Along with draught-proofing, improvements in shade solutions offer a significant, low cost, thermal performance improvement for a home. We worked (and continue to work) to introduce new shading to the home. We now have introduced shading to all external surface windows that require additional covering. This means all windows on the western, northern and southern sides of the home. Obviously in a southern Australian environment the shading of deciduous shrubs and trees provide a natural shading option. But we decided not to pursue this option for reasons of space, garden layout (and changes we may want to do to that in future, but are not in a position to do now) and also because weather variability in Melbourne (for example, cool, overcast days in mid-summer) make a heavily foliaged plant (in that example) a fairly inflexible shading solution. Instead we opted for various types of blinds as external shades, introducing them over time according to where we got the most significant benefit and as our budget allowed. The blinds installed included:
• one standard fixed arm awning with high UV factor blockout solar shade, see-through for those standing inside the house. Because of its location and its fixed arm structure holding it out from the window, this blind requires infrequent movement and is not motorised.
• one three metre high, one metre wide motorised and internally controlled roller-shutter for a relatively inaccessible window facing full-west (our most expensive shading option). Because this window is in a concealed area, the roller-shutter option also significantly increased security for that window.
• Six straight drop external blinds with high UV factor blockout solar shade, see-through for those standing inside the house. The straight drop nature of these allow them to fit into tight spaces and reduce cost. Our windows are top-opening awning windows but because of our local climate, we are unlikely to want to open them when we have the blinds drawn (high temperature sunny days). These are not motorised and, for our circumstance, are very easily pulled down when a high temperature day is forecast and retracted when the angle of sunlight has moved appropriately (despite what most blind vendors will tell you about the necessity of energy-drawing, high-cost motorised versions for any application).
These eight shading solutions have made a very significant and very, very noticeable difference to the climatic ambiance of the house.
Next post I will say some brief words about internal shading…..
And here are those caveats once again….
1) whilst there are technical fixes that can contribute to energy reduction, we wanted to make sure that we didn’t concentrate exclusively on them. My gadget-attracted persona is fascinated with new photo-voltaic cell technology or the latest approach to circulating filtered warm ceiling air into the house. We consider these approaches but also try to make sure that lower cost, high impact corrections are prioritised. What good is an extremely expensive solar ventilation system if the house leaks air like a sieve?
2) Related to this point, we are aware of the relative economic capacity we enjoy that allows us to make some of these changes simply.
3) So we want to avoid seeing this as a way we can “proof” our little home against the rest of the world. 90000 litres of localised water storage might be fine if it makes sense in the context of your local rainfall and reasonable water usage. It doesn’t make much sense if it is to safeguard your lifestyle while the rest of the world runs out of water.
4) And part of the reason for adding these thoughts to this blog is to add to the conversation about what is possible and keep us all thinking about ways we can contribute to this kind of work for ALL dwellings, regardless of personal economic capacity.
5) Our efforts are not necessarily particularly remarkable in the scheme of things, but its fun to tell the story, to be encouraged in what you are doing and to encourage others.
I am writing about your caveat (1) - what good is an expensive ventilation system if the whole house leaks like a sieve?
ReplyDeleteWe have a Californian bungalow (c 1915), which has inbuilt vents in all the major rooms, lead lighting, huge cracks under the doors which have shrunk in the last almost 100 years, etc.
We did go for the expensive option of the ventilation system: and it works! We estimate that the internal house temperature varied from 30C+ in summer to about 5C in winter before our ventilation system was installed. Now for the last year our house temperature has ranged from 13C - 26C. Much more liveable temperatures. On hot summer mornings or cool winter mornings we need to check the weather forecast and current temperatures before leaving the house because the outside temperature and inside temperatures are so different. And we have had NO humidity inside. All for the cost of running a light globe.
The ventilation system works so well because the filtered air pushes out air through all the cracks and vents all the time, preventing hot or cold air from directly entering the house.
A leaking house is no reason to not have a ventilation system.... and it is so much cheaper to run than air conditioning.
See my comments on http://www.gift-a-blog.net/2011/02/operation-household-energy-reduction_16.html. I understand that for some it may make sense. For our crcumstnace it does not.
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