[Ferro List] 3 questions for Walter

[Walter Jeffries]

On Feb 27, 2008, at 3:50 AM, Janoahsh wrote:
> Ahh here we go again.  Thank you for asking this question Keith,
> Condensation Buildup.
> I think this problem comes and goes with temperature extremes and  
> interior
> use.

One thing that may be helping us is we have a lot of air circulation.  
We draw in fresh air through earth air tubes which are pumped via  
chimney effect from the rise up the mountain and then past the back  
of the wood stove. Additional tubes rise from the floor to ceiling  
past the back of the wood stove. The wood stove exhausts a lot of  
air. The result is we have a lot of air circulation and incoming  
fresh dry air from outside all winter.

The bathroom is at the end of the air cycle having a vent that takes  
the moist air out through a chimney of its own. This removes the  
moist air. The kitchen also has a vent but more importantly is right  
next to the bathroom so air flows into the bathroom and out of the  
house.

In the design of the cottage I spent a lot of time figuring out the  
air flows. It was worth it. When we turned on the interior  
circulating vertical pipes (opened their bottoms) we went from having  
a 10°F difference between floor and ceiling to having a 1°F  
difference. It worked even better than I had expected. I have things  
setup so that I could have added a large circulating fan in the  
cathedral ceiling and a muffin fan at the top of each of the three  
vertical air tubes but that has proved to be unnecessary. I like that  
as I prefer not having the noise, electrical usage, mechanical system  
to maintain, etc. Passive is best.

As mentioned in the other post, we are sealing the interior on a high  
cement parge so that should also help. I have wondered about waxing  
the entire interior surface but don't think it is necessary. I have  
yet to actually do any waxing so I may change my mind after we've  
done that on the bathtub, kitchen counters and the library desk.

Another factor may be that we keep our home fairly cool thus there is  
less differential.

Temperatures do get down to -45°F in the winter here and we get a lot  
of wind. -20°F has been our low for the past two years so it has been  
considerably warmer. Snow depth is about 4' of pack and that helps.

Janosh, where are you located in Alaska? I lived in Fairbanks, Kenai  
and Anchorage at various times.

One thing you've made me wonder is if outside along the eaves I  
should put ventilation for the insulating roof lightweight concrete  
much like conventional construction has. That would let moisture vent  
if it did get into that layer. Something to ponder.

> I also plan to incorporate vented tubes in the walls that will  
> supply warm
> dry air if needed to dry them out.

I wouldn't put the vent tubes in the walls based on my experience  
with them in our old farm house. I didn't do that but I did measure  
the temperature with probes in lots of places. The air tubes can  
create cool spots if you do it that way. Instead, on the new tiny  
cottage I brought all the air in along the floor at the base of  
walls. We also have outgoing air tubes that drain away the coldest  
air in the cottage from the lowest points. This lets the cottage  
breath. Our cottage is so tight that it is hard to open and close the  
door if you have all the vents closed. The vents are necessary,  
otherwise when you open and close the door the wood stove will puff  
back - ick!


Cheers,

Walter Jeffries
Sugar Mountain Farm LLC
Orange, Vermont
Pastured Pigs & Sheep
http://SugarMtnFarm.com/blog
http://HollyGraphicArt.com
http://NoNAIS.org

Print to pass out: http://NoNAIS.org/handout
Print to hang up: http://NoNAIS.org/poster
Print for people offline: http://NoNAIS.org/printout
Stickers with NoNAISewe Logo: http://NoNAIS.org/stickers
Ad copy is available here: http://NoNAIS.org/ads