[Greenbuilding] PassivHaus and NZE comparison

[jfstraube]

Sheesh Gordon, not sure what you meant by the "the company of facts and knowledge" but I would say there is quite a bit of that on this list.  Sounds kind of derogatory, and yet Ross is one of the "good guys" (eg he is willing to have a rational conversation) and I basically said what you said.  
Most of the "facts" you provided are available to anyone surfing the web and/or talking to CMHC folks.  All of them were built into my commentary.

However, it is not true that NZE homes meet the PH standard.  That is my point.
I attach a table of 5 of the houses I compared recently at the bottom of this message.
According to CMHC, the Riverdale Duplex (eg one wall less than a single family house to loose heat) uses 33 kWh/m2/yr.  This is over twice the PH standard, eg no where near the target.  I think the Riverdale house is a exemplary cold climate home, a real step forward.  And that is my point: you met the 0.5, but not the 15 heating target and yet use less energy than a PH by about 120 kWh/m2/yr. The Ottawa ecoHome fails the 0.6 test and the 15 test, and the GreenDream meets the 7 and fails the 0.6.  (Note the Kamloops gets this low by using a ground source heat pump and using a COP = 5.1, which is crazy, and reality will certainly be closer to COP=3.5).
The 120 primary target is an arbitrary but sensible target. By beef is the 15 and 0.6 numbers, and the lack of climate response and renewable energy sources.


Avalon	Riverdale	ecohome	GreenDream	Now
Location		Red Deer Alta	Edmonton	Ottawa	Kamploops BC	Toronto
HDD (18C)		5500	5600	4600	3650	4000
Floor Area (heated m2)	240	234	310	284	139
Total Site Energy (ekWh)	13094	14391	20646	11031	13475
Heat Energy (kWh/m2)	23.9	33.7	40.2	7	23.1
Roof (R)		87	100	60	60	36
Wall		70	56	44	44	40
Window		5	7.3/10	5.7	4.5	5.7
Basement walls	none	54	40	44	25
Slab		60	24	15	20	25
ACH at 50		0.5	0.5	0.65	0.68	2.6
PV Installed (kWp)	8.6	5.6	6.2	6.8	2.7
SHW produced (kWh)	3886	1907	6665	2099	1824
PV produced (kWh/yr)	9569	6224	8184	9963	2800
Notes			Duplex			Not NZE

On 2011-01-26, at 12:22 PM, Gordon Howell -- Howell Mayhew Engineering wrote:

> Hello Ross and John:
> 
> May I recommend that comments on solar PV on NZE homes be made in the company of facts and knowledge.
> 
> The first NZE home in Edmonton cost $110k more than standard construction, see < www.riverdalenetzero.ca>.  If we built it as standard construction, it would have cost $250k for the solar PV system (in 2008) and have been 205 m2 in area.  No-one in their right mind would do something like this ... instead we added energy efficiency measures (envelope and appliances) until the incremental capacity cost ($/kWh/year) of energy efficiency was roughly equal to the incremental capacity cost of PV at the time.  Then because energy efficiency is so vastly cheaper than PV (even now) then the incremental cost of the house was reduced to about $25k for energy efficiency and $35k for solar thermal, and $50k for solar PV.
> 
> The next two NZE homes, Mill Creek < www.greenedmonton.ca> and Belgravia, are in around the $70k incremental cost... why?  Same energy efficiency measures, more passive solar (south windows), very simple solar thermal (on Mill Creek) and zero solar thermal (on Belgravia) and price of PV continues to plummet.  Add to this that the Alberta government provides a $10k incentive for EGH 86 houses and the incremental cost to the homeowner is around $60k.
> 
> So I wish PH people would get off the pot on their comments about "The Net Zero homes use exorbitantly expensive renewable energy systems to push them to zero"... we only put on solar PV when the ultra energy efficiency measures are in place... and these measures roughly equal the PH standard.
> 
>> 


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