[Greenbuilding] simple energy-less home

John Straube jfstraube at uwaterloo.ca
Sat May 25 11:58:13 CDT 2013


BTU and kilowatts are directly connected to a physical event.  You would need to take a physics course to understand how, or do a wiki search on BTU.

I remaining amazed, shocked even, that members of a green building list seems to think dollars measures energy.  I am really trying to understand how.  Perhaps it is because most people dont have experience with travel or time.

A PassivHaus house started this discussion-- based on it using $100 per month or something rather than telling us how much energy.  That $100 is almost useless as measure of energy used, or pollution produced.

Let consider some examples so you might understand my exasperation:
If you are using electricity in Long Island NY, you are paying around 27 cents per kWh for electrical energy (same as many parts of Europe, Japan)
If you are using natural gas in Ontario, you are paying around 3 cents per kWh of energy.  
That is a factor of 9 difference I can pull out of my head based on consulting work. There are wider variations.   So, if someone states "This green building strategy saved $X" these geographical price variations render the previous statement almost useless, as one would not have even a rough estimate of the energy involved. Like we don't have even a rough estimate of the Maine house's energy use.

It gets worse.
Fixed charges may consume more than half the monthly bill in a low-energy building, and ten percent or less in a high-energy building.  This results in a further distortion in the order of a factor of two or three!

And then we look at history (time).
When I look at solar house articles from the 70's and early 80's many articles quote "This approach saved $Y" or "this house used only $Z".  Today that information is useless.  The house articles that quote "The passive solar features of the home reduced heating energy use by 7 million BTU" are still useful and valid.  Because BTU is a measure of energy, and $ is not.  

Dollars are NOT a functionally relevant unit for discussion about energy use in houses.  Except your house from this month to last month.  This year to last year already becomes a suspect use because of inflation and certainly over a period of ten years we are typically already talking factors of 2.  And you can't compare your house energy bill with the low energy house next door because of the fixed charge effect.

Money matters when people are trying to make decisions about …. money.  how much money should I spend versus how much do I need to invest.  Perfectly valid approach if that is your goal.  the information is very regionally specific, and valid for only a short time, but perfectly fine for the goal.  

If the concern is "green building" aka, pollution, resource use, etc. then energy is a pretty darn good (not nearly perfect) metric.  Dollars are essentially useless because, from the above, to say something "saved $X of energy" could be 1 energy units, or 20 Energy units.  
With that low level of precision, there is little to no hope of advocating for green buildings on the broad scale I believe we need.


On 2013-05-25, at 10:44 AM, Steve Satow <naturalbuilding at shaw.ca>
 wrote:

> 
> On 2013-05-25, at 7:27 AM, Topher (and various others) wrote:
> 
>>> Dollars are not a measure of energy use.
>> 
> Well, given that kWs or Btus or litres or degrees or minutes and just about every other form of measurement not associated with a natural event (such as the rotation of the earth or circling of the Sun) are arbitrary concepts invented by some person or persons for convenience at some time in the past, I don't see why it isn't just as valid for the majority of the population to adopt dollars as a unit of measurement for energy?
> 
> It may not be as accurate and therefore as useful for scientific purposes, but no less functional.
> 
> Just a thought! :)
> 
> Steve.
> 
> 
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Prof. John F Straube, P.Eng.
www.BuildingScience.com







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