Re: Passive House - energy efficiency
From: Norman Gauss (
Date: Tue, 23 Aug 2011 22:23:30 -0700 (PDT)

I live in a condo complex built in 2004 on the Central Coast in California.
We are far enough away from the ocean to have freezing temperatures in
winter and triple-digit temperatures in summer.  Our homes were built with
air-tight windows and doors, yet none of them have HRV's.  None of the homes
have HVAC systems that provide air-exchange, either.  In winter and summer,
unless we open a window, we breathe stale air.   Is California code out of
date or do you suppose it has been improved since 2004?

Norm Gauss

-----Original Message-----
From: James Kacki [mailto:jimkacki [at]] 
Sent: Tuesday, August 23, 2011 9:46 PM
To: Cohousing-L
Subject: Re: [C-L]_ Passive House - energy efficiency

Reply to Norm's question:
Air exchange is a Code requirement now and it is most often accomplished by
an HRV (Heat Recovery Ventilator). Indoor air is blown out through the HRV
and outdoor air is sucked in through the HRV.  The air is passed through
many adjacent fins so that the heat is exchanged  for energy efficiency.
The best ones are, I believe, about 80% efficient James

On 23-Aug-11, at 4:01 PM, Norman Gauss wrote:

> How do these tight thermal envelopes solve the problem of indoor air 
> quality?  Unless some fresh air is exchanged for stale indoor air, 
> indoor air quality is likely to become very unhealthful.
> Norm Gauss
> -----Original Message-----
> From: Fred H Olson [mailto:fholson [at]]
> Sent: Tuesday, August 23, 2011 1:04 PM
> To: Cohousing-L mailing list
> Subject: [C-L]_ Passive House - energy efficiency
> In her message "Lancaster update, and ..."
> On 19 Aug 2011 Fiona Frank wrote:
>> Lancaster Cohousing is building 34 passivhaus houses and a common 
>> house at Forge Bank on the banks of the Lune River 3 miles outside of 
>> the small north western UK city of Lancaster
> "passivhaus houses" caught my attention since in recent months I have 
> become interested in this very high standard or energy efficiency. In 
> the US the phrase "passive house" is used widely instead but this term 
> is easily confused with the term passive solar building design.  The 
> two terms are different.  To further confuse things passive house 
> designs often incorporate passive solar.
> The passive house standard was mentioned briefly on cohousing-L 
> previously 
> but warrants more coverage.  IMHO any new construction should take the 
> standard into consideration.
> Excerpt from
>  The term passive house (Passivhaus in German) refers to the rigorous, 
> voluntary, Passivhaus standard for energy efficiency in a building, 
> reducing its ecological footprint.  It results in ultra-low energy 
> buildings that require little energy for space heating or cooling.
> Key to achiving the standard is super insulation and a very carefully 
> and tightly constructed thermal envelope.
> This and other features result in a conventional central heating 
> system is not being necessary.  A typical statement is that a passive 
> house can be heated with the equivalent of a hair dryer.
> Passive houses are up to 14% more expensive upfront than conventional 
> buildings but this is quickly recouped from energy use savings.
> Retrofitting a house to meet passive house standardds is possible but 
> much more difficult than with new construction.
> We had a passive house architect evaluate our house and concluded with 
> him that it is not reasonable to retrofit our house to the standard.
> Fred
> --
> Fred H. Olson  Minneapolis,MN 55411  USA        (near north Mpls)
>      Email:        fholson at      612-588-9532
> My Link Pg:         My org:
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