PassivHaus

[Mikesolar]

So, it seems that the American people who promote the PassiveHouse name (either PassivHaus or other) promote products or techniques that don't meet the specs of the international PassivHaus organization.

Therefore, I am told, that if you want to get a house certified it may take some work to find out who to go to. Here in Canada we can use the European requirements so it isn't an issue here. There are builders certified to the US standards but I don't know if they meet the European standard.

Just wondering what anyone else has heard?

[SDMCF]

Have you seen this article?

I don't really understand the PassivHaus standard. They have a Specific Primary Energy Demand of ≤ 120 kWh/m2. Yr which seems to me very generous. Even my house - built in the 1890s- easily meets that. They also have a Specific Heating Demand of ≤ 15 kWh/m2. yr which seems comparatively strict, at least in our climate. My house is nowhere near that. I can't relate the 2 measures. In many climates the energy required for heating is far and away the biggest requirement, but it is a fairly small portion of the allowed total. I must be misunderstanding something I guess.

[Mikesolar]

No one I have talked to pays attention to the 120kwh/m2 only to the 15kw/m2 and if you can get to this level, the biggest load in the house becomes DHW.

I brought this up because I am working on a 3 floor, 380m2 passivHaus and we are struggling to select the heating system. The owners are leaning towards radiant tubing and 40mm of thermal over pour (gypcrete) even though it is a high cost for very little heat output. It does, however, make the heat very even and has other benefits (sound and fire).

The option to this is at least 6 heads of ductless (although we have gas on the street, we are not having gas in the house) and an ERV made by Air Pahoda, currently the most efficient one on the market. The ERV was delivered a couple days ago.

As we know multi head units are not as efficient as single head units so if we went this route, there would be a lot of infrastructure. so the option is to have one larger heat pump heating a water tank for both DHW and the floors. Total heat and cooling loss is estimated at 7kw (24Mbtu).

[AC_Hacker]

Originally Posted by Mikesolar

...cooling loss is estimated at 7kw (24Mbtu).

Check your math??

-AC

[AC_Hacker]

Originally Posted by SDMCF

...They have a Specific Primary Energy Demand of ≤ 120 kWh/m2. Yr which seems to me very generous. Even my house - built in the 1890s- easily meets that...

As I understand this statement, The Specific Energy Demand (total yearly energy consumption) is <= 120 kWh/m2 per year (total).

So if your 1890 house is 75 m2 (total wild guess), then your total annual energy use would be 75 * 120 = 900 kWh for the year.

Or about 75 kWh per month (total), on average. Of course, there would be seasonal variations.

So, your 1890s house has the ability to perform this well?

I live in a far less climatically challenging area (Portland Oregon, USA) that you do (Finland), and I am struggling to get my 1890s house any where close to 75kWh per month. In fact, in my least-use months, I'm still using 6 times as much, even after all my work.

You must tell me your secrets!

-AC_Hacker

[Mikesolar]

7.000 x 3412btu=23884 btu or, 23.8Mbtu (I know M should be K but look at any boiler spec and it is in Mbtu and this is what I am used to)

[AC_Hacker]

Originally Posted by Mikesolar

7.000 x 3412btu=23884 btu or, 23.8Mbtu (I know M should be K but look at any boiler spec and it is in Mbtu and this is what I am used to)

So how would you express 23,884,000 BTU?

is 23884 BTU = 23.8 Mbtu a metric thing?

I was under the impression that in metric:

1,000,000 = 1,000 K = 1 M

That's the way it is in the world of electric phenomenon, and all other physical phenomenon that I know of.

-AC

[Mikesolar]

Originally Posted by AC_Hacker

So how would you express 23,884,000 BTU?

-AC

Usually 23,884Mbtu. I know, it's dumb but it is the convention.

[AC_Hacker]

Originally Posted by Mikesolar

Usually 23,884Mbtu. I know, it's dumb but it is the convention.

How broadly is the convention accepted?

Is this a convention that is only seen in the Canadian boiler industry?

Is the US boiler industry also using this convention?

Have you ever seen it anyplace else?

I mean, if it is confined to the Canadian boiler industry, and since this forum is regularly read by a world-wide audience, maybe referencing your frame of reference would be useful in avoiding confusion.

Maybe something like:

7kWh x 3.412btu = 23.8Kbtu or, 23.8Mbtu CBS (CanadianBoilerSpeak)

Just a suggestion to avoid any intercontinental confusion.

-AC

[SDMCF]

Originally Posted by AC_Hacker

So if your 1890 house is 75 m2 (total wild guess), then your total annual energy use would be 75 * 120 = 900 kWh for the year.

Oh, you do your arithmetic a little differently over that side of the pond. When I went to school 75 * 120 was 9 000 not 900. Or 750 per month.

I am struggling to get my 1890s house any where close to 75kWh per month. In fact, in my least-use months, I'm still using 6 times as much, even after all my work.

6*75=450 which is well under 750.

You must tell me your secrets!

No real secrets, just:

- some ability at basic arithmetic

- economies of scale (my house is 724 sq m, not 75, so the PassivHaus target is 7 240 kWh per month; not exactly stringent)

- additional wall insulation, inside and out

- good attic insulation

- well-insulated hot water storage

- GSHP for heating

- 5 x 20 tube solar collectors

There is still much more I can/should/will do to reduce my energy consumption. My approach is for slow but constant improvement.