Whole House Fans w/out attic

Old 05-09-01, 11:11 AM
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As a follow-on question to woman in SoCal... I live in SF Bay Area - same problem - rolling blackouts, soaring electrical bills. Need help cooling.

Our house is a two-story townhouse with reverse design - bedrooms downstairs, living/kitchen upstairs. The upstairs has vaulted ceilings and sky lights, two ceiling fans (which are totally useless...), open floor plan (no way to close off individual rooms), no attic. The house was built without a/c and is very efficient holding in heat. When temps outside are in the 80s, house heats up to over 90. We have double-pane windows and a/c installed last year. We are looking for some way to vent the hot air out of the ceiling and am trying to get information about fans in the roof.

I'd like to know if I can use an attic fan in a house without an attic or do I look for "whole house fan". Is there a difference? The volume to be vented is large - upstairs is about 900 square feet of floor space - add to that two story ceilings in the whole upstairs.

Old 05-16-01, 08:23 PM
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I'd like to know too

Sorry I don't have an answer for you, but I have a similar situation with my english tudor house in Chicago. The upstairs has vaulted ceilings and no attic. I'm not how much if any insulation there is, but it gets super hot up there around 4 pm when the sun hits the roof outside directly. What can I do to get the hot air out? The central ac doesn't get up there too well plus the thermostat is downstairs which stays pretty cool unless its like 100 out.

Old 05-17-01, 03:03 PM
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I will try to help

Hopefully others key in.Restaurants use a "mushroom" exhaust fan to remove heat and combustion gases from cooking equipment.They have alot of different applications.They can be mounted on a side wall,pitched roof, or flat roof.The CFM or air flow you wish to move comes in a bunch of different patterns.Duct work may have to be added and a thermostat should be installed to cycle fan on and off.These "EXHAUST" fans are a low maintence,low power consuming item compared to running mechanical refrigeration.PDF
Old 05-17-01, 04:05 PM
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You mentioned you have skylights...How about refitting them with the type that open? Open a window downstairs and the skylight, and presto, whole house venting.

Another opion: do you have a garage connected to the house? What about installing a whole house fan (in a wall if necessary)to vent the garage? Open the connecting door and windows in the house to allow the air flow.

I have a similar problem with my house. I've even thought about putting a whole house fan inside a bay window. The vent path would be in the shape of an upside down "U". The holes would be facing down both inside and outside. Have not tried it yet, just in the planning stages.

Good luck.
Old 05-21-01, 01:04 PM
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Venting w/o attic

I have been watching this posting with great interest to see if anyone could recommend a house fan for homes without attics. Seeing none so far, I'd have to agree with the idea of an opening skylight. That seems the most logical. Plus, if properly installed, they are very attractive and would add value to your home for their looks as well as their cooling function. It certainly seems conceivable that a forced-air system could work, but I've never seen or heard of one other than the restaurant-style units already mentioned. I'd be wary of those if you live in a cold climate. They are basically a big hole in your roof with a cap to keep the rain out. I used to run a youth camp and we had to plug ours up with insulation (and disable the switch) all winter due to the cold air drafting in so badly. By comparison, whole-house attic fans have a gravity-based louver that closes automatically when the fan is off. Unfortunately, that also means they probably won't work upside down, but I'm guessing. Maybe it could be rigged.

Also, if you're "lucky" enough to need roof replacement soon, this is a great time to put in those skylights and be sure to choose a light colored shingle to reflect a lot of that heat away. That can make a big difference and easily outweighs the benefit of holding heat in winter months.

This is a tricky one!
Old 05-30-02, 09:21 AM
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Bringing this old thread back to life!

It's that time of the year again - it's warm and my 2nd floor is miserable!!

Anyone have a guess as to what a small A/C system might cost for an upstairs? I would really prefer a forced air system of some kind that can be controlled via a wall mounted thermostat. I would essentially block off the ducts from the first floor/basement existing furnance system and use the new one for just the upstairs. The upstairs is cold in the winter too so I'd probably want something that could be used to heat as well (electric system to avoid running a gas line upsairs I think).
Old 05-31-02, 09:35 AM
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I'm not quite sure if you're looking for options for cooling rooms without attics, like cathedral ceilings, or a way to supplement the heating and cooling in your home for this room. Besides the skylight, which I don't like, some solutions would be a cold roof, ducted whole house fan, ceiling fan or a ducted recirculator.

I'm going to answer the last post. The solution to your problem is to supplement your present system with a ductless heat pump. You can go to http://www.mrslim.com and they show you the different type of units they have. They have units that recess in the wall or ceiling, remote control and programmable. These units are geared for smart house technology, so if you have the program in your computer, you can control it to meet your needs, turn it on and off remotely, like from your car, voice recognition, etc..
Old 05-31-02, 12:02 PM
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Thanks for the referral! The Mr. Slim product might be exactly what I need. I also have a problem wiht it being a little too cold in the winter time and this product would solve that problem as well.

Thanks again.

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