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Old 06-08-14, 04:32 PM   #104
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Originally Posted by stevehull View Post
...If an HRV (or ERV) were constantly used, then the elevated CO2 would not be an issue...
Which is the whole point of my CO2 controller for an HRV.

No HRV is 100% efficient when it runs... there is a constant heat loss during it's operation, even with the best of them.

A CO2 controller can optimize the air exchange rate of the HRV, and run the HRV at the volumetric rate required to suit the occasion, thus minimizing the heat loss.

You don't have to choose between a CO2 controller and a HRV, it is a short-sighted and limiting point of view.

You combine them to get the optimum benefit.

Be aware that he has a very small home and he has sealed it almost like a boat. In his case, about 1 home in a million (or less), he does get elevated CO2 levels frequently.
This is all true, I actually am trying to apply the rigor of Passive House construction in retrofitting my 1892 house... it ain't easy as a retrofit. It would be much easier and more effective employing these techniques during construction, as BBP has the opportunity for. But at any stage, it is the way of the future. Be mindful that ALL passive houses require mechanical ventilation, and the efficiency of these HRVs is specified to be 85% minimum.

If I also lived in Oklahoma (as S.Hull does), a state that discourages solar installations (through energy taxes that are tantamount to a tax), and also has one of the lowest natural gas price levels on the planet (which minimizes the incentive to opt for efficient and other earth-friendly alternatives) , I'd be likely to advise a casual attitude toward energy conservation, too.

Thankfully I don't, I live in a state that has a very progressive attitude regarding energy, and that has informed my thinking.

I'm not an HVAC technician. In fact, I'm barely even a hacker...

Last edited by AC_Hacker; 06-09-14 at 01:01 PM..
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