Attic-fan (PAV) suggestions - unvented soffit

[Shawn]

I live in a condo, and have major limits on the types of improvements that I can make. I have an end unit, with a finished loft that is unbearably hot. If it wasn't for the loft, I'd barely run my air conditioner throughout the summer. The rest of the condo (first floor) stays pretty mild with the exception of just a few days in the summer.

In an attempt to find solutions to the problem I've researched exactly what is installed. There are no soffit vents - it's just solid siding-like material with no perforations or venting at all. There are no gable vents, of course on the one side due to a firewall, and the outside wall doesn't have one. There is a ridge vent. The rafters are 2x8, with what looks like about R-19 installed, and I can see some sytrofoam baffles in some of the cavities.

I'm giving serious consideration to a powered attic ventilator, although I understand the issues with them and negative pressures. That seems to be my only option at this point given the fact that I can't install soffit venting or gable vents.

If anyone has another suggestion that might be more effective I'd love to hear about it. Thanks.

Shawn Elkton, MD

[<natebrazil]

What are the "negative pressure" issues with attic ventilators? I have one and would like to know if there is a detrimental effect with using it.

Thanks, Nate

[RBM]

I would first check with the condo association to see if they&#39;ll let you cut the roof. I put one in for a condo customer some years ago and they made him take it out and patch the roof

[Shawn]

[Shawn]

[RBM]

[Buck Turgidson]

Ceiling fan?

[Bob]

Without soffit vents, the powered ventilator will "short-circuit" the ridge vent. You really should have vents low and high, of about equal area, to get natural ventilation through the whole area.

If you don&#39;t need the air conditioning, you could put a "whole house fan" into your unit, exhausting the inside air through the attic, thus ventilating your unit and cooling the attic. You might need some way to close and insulate the fan opening during the winter. I have a 1 foot "attic gable exhaust" fan I place in the attic access opening for the summer which does a very good job of cooling the house. I control it using an X10 remote control. Just opening the access hatch gets some ventilation going.

Bob

[Phil Scott]

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Rule 1 in the plumin&#39; bidness... &#39;what doesnt come in, cant be sucked out&#39;

Accordingly what ya needs is two vents...near the ridge.... one of them powered... about 100 sq inchs each per every 500 sqaure feet of attic being vented. The vents should be widely separated ...or the passive vent should be ducted down about 3&#39;.

Phil Scott

[Bobby_M]

It&#39;s ridiculous that the company that did the roof (and ridge vent) did not tell the association that the ridge vent is absolutely useless without a low vent to allow air in. As wind flows over the ridge, it creates a negative pressure to draw attic air out. Without a way for new air to get in, the air just sits in the attic. I would seek out a professional to draft a position letter that you can send to the association to have them consider retrofitting gable end vents. If they don&#39;t consider doing it in all the units, at least you can make a better case for allowing YOU to have it done near your own unit.

Bobby

[ds549]

bottom line is ,,you need eve vents . lucas

[CWatters]

For example...

"a Colorado family of three who died from carbon monoxide poisoning when an attic ventilator caused the furnace to backdraft"

[JR-jred]

I don&#39;t know how old the condo is but if it&#39;s less than 5 years or so, your association should be looking to the developer to remedy what is a significant construction defect.

Otherwise, they should fix the problem themselves. Whatever it costs to put in soffit vents and baffles in each unit now will be small potatoes compared to replacing the roof including shingles, sheathing and likely a few structural members in a few years, and at the same time, installing the soffiit vents which should have been there in the first place.

If you&#39;re planning on being in that condo more than a year or three, you might want to start making some noise on this right away or you could be in for a serious special assessment to repair the inevitable damage.

Ounce of prevention/pound of cure, etc.