Lacustral wrote:
I've been told that getting my roof ventilated is probably the most
important thing to do for passive cooling. The ventilation is pretty
poor now.

The basic building code asks for 1 sq foot of NFA (net free area) of
ventilation per 300 sq. feet of attic space. And 1/150 if you have
insulation in there without a vapor barrier, which i do.

Does more ventilation than that cool down the attic and the rest of
the house better? It's not really a lot of ventilation.

Yes, but maybe not all that much. If you have insulation the specified
amount is OK. If you are given the opportunity to add more at a low cost
then do it. It is hard to have too much.


It seems like intake ventilation is easier to get than exhaust
ventilation. People have suggested ventilation plans to me that give
far more intake than exhaust ventilation. Do you get any extra
cooling from adding intake ventilation over the amount of exhaust
ventilation?

Not all that a good design. It will work based on the lowest common
denominator and in that design it would be the exhaust. What comes in (cool
air) must go out. You don't want a lot more exhaust however as that may
draw conditioned air from your living spaces.


For exhaust ventilation, people have suggested ridge vents and
louvers. I might need both to get enough ventilation, the ridge is
very short.

Either or both is fine. I now have both as I took a new roofing job as
a opportunity to upgrade.


Laura

--
Joseph Meehan

Dia duit