re: problem with winter dryness
25 nov 2004
gary r. lloyd wrote:
>>>what are the pros and cons of tighter construction with forced
>>>ventilation versus passive ventilation (leakage), assuming they both
>>>result in roughly the same amount of ventilation?
>>here's my opinion:
>> advantages disadvantages
>>a) natural leakage lower first cost higher fuel consumption
>> more reliable in winter and summer
>> possibly better iaq: can't use hrv
>> co, co2, h20 often lower rh in winter
>> diluted with a wet insulation and drywall
>> large flow of possible wood rot, mold,
>> fresh air and mildew inside walls
>> ***no ventilation at all
>> on still mild days***
>>b) positive ventilation more uniform fresh air
>> and temp distribution
>> around the house
>> it's always easier to
>> bring air in than to
>> keep it out, turning
>> b) into a) if needed...
>in case you haven't noticed, what i've been trying to do here is to
>get you to present a case for your strategy that is based upon why
>this is good for the homeowner, rather than why it is good for your
>political agenda. i remain unconvinced.
pity. btw, i'd call the information above unbiased, albeit my opinion,
and that of many others. how would you change it?
>at the very least, there should be enough *passive* introduction of
>outdoor air, be it through leakage or controlled flow, to keep people
>from passing out (over 5 cfm per person), and then pump in the rest.
sounds good to me, on the coldest day. airtightness costs money. why
overdo it? those few cracks and crevices can be bidirectional air-air
heat exchangers with a bidirectional fan in an indoor partition wall.
btw, extra air leakage also increases ac bills.
>and i am also not convinced that people outside of acclimated desert
>dwellers are comfortable and/or healthy at 20% humidity.
pity. you might look at the ashrae 55-2004 standard.
>gary r. lloyd cms
>hvacr troubleshooting books/software
with these "credentials," it's darkly amusing that you know so little about
building science :-) i'm only one of thousands of engineers and architects
around the world who recommend reducing air leakage in houses. you might
correct your lonely arrogant ego-filled ignorance by taking an ashrae short
course on ventilation or joining the society of building science educators
(sbse). they have a nice web site.