Waaay OT: Any HVAC experts out there?

[Wayne77]

Just moved into a new home. It's a rambler with a "bonus room" above the garage. Right now I've got my home theater up there but the AC kinda sucks in that room - all the hot air settles up there with no where to go. Everywhere else in the house the central air system works great. I put a floor standing fan in the room but it's loud and doesn't do much. What else can be done do get better cold air flow up there? I don't want to put one of those ugly window mounted ac units in the only window in the room since it's on the front of the house. Is there a way to install a fan in the ceiling that sucks the hot air into the attic? Or is there a decently priced compact ac unit that I can stick in the corner somewhere? Maybe a ceiling fan?

To keep this bike related, I'd like to have a nice comfy room to watch the Tour. Thanks!

[JasonF]

Funny you should mention this Wayne...I have the same setup, it's our home office/tv room above the garage. It's a pretty big room and the a/c just doesn't have the horsepower to cool the room effectively. Add that to the fact that our house faces the south and gets about 10 hours of direct sunlight in the summer, and it gets awfully hot up there. We have installed a ceiling fan, and while it helps, it's not enough.

As you alluded, your next best choice is a window unit. I also agree that I'm not crazy about the aesthetics. With that in mind, you could pick up a floor-standing air conditioner. You will still have to vent it to the outside, but at least it won't hang over a window.

If you don't want to spend the money, you can follow the advice given to me by a Texan: open everything up at night to cool the room. During the day, keep the garage doors closed and use some dark shades to keep heat and light out. When we follow this advice, it's good for 5-10 degrees of lower temperatures. Good luck!

[mike p]

A whole house fan installs in ceiling and has louvers. Sucks air from whatever windows you have open and blows into the attic. Attic must be well ventilated. I'm not sure how it would work with ac as you would have no windows open.

Mike

[Smiley]

Free worthless advice , you should :
install an attic fan to suck that traped air in the attic out of the space.
install boster fans in the ducts that delver air to this space, bear in mind that this will ROB air from other rooms in the house
better yet install a Sanyo split A/C system in this space and like my brother keno says Forget about it !!!

These Sanyo systems are attractive and will do the job with minimal intrustion of your space and they are quite. Not the cheapest fix but they work great. I assume your garage is not cooled either and your issues are compounded when you drive your warm car into the garage below. I have a A/C garage and two rooms above this space thats 24 by 24 and I have 2 tons of cooling dedicated to this area , mainly the rooms above with only 2 bleed registers to temper the garage if that helps you any.

Yes I am a professional engineer and i work in the HVAC field .

[JasonF]

A whole house fan installs in ceiling and has louvers. Sucks air from whatever windows you have open and blows into the attic. Attic must be well ventilated. I'm not sure how it would work with ac as you would have no windows open.

Mike

I forgot about that Mike...I used to live in a condo with a whole house fan. It was incredible. The louvers would open when the fan was turned on and would suck all the air out of the condo. The fan was so powerful that it would blow out our pilot light if we didn't open any windows for cross ventilation. I'm not sure how much it would cost to install such a fan. I do know that portable air conditioners run about $400.

[Wayne77]

Yup, my house is South facing too. Its great for the back yard during the summer but not so great for the front facing rooms.. Thanks for the advice!

Funny you should mention this Wayne...I have the same setup, it's our home office/tv room above the garage. It's a pretty big room and the a/c just doesn't have the horsepower to cool the room effectively. Add that to the fact that our house faces the south and gets about 10 hours of direct sunlight in the summer, and it gets awfully hot up there. We have installed a ceiling fan, and while it helps, it's not enough.

As you alluded, your next best choice is a window unit. I also agree that I'm not crazy about the aesthetics. With that in mind, you could pick up a floor-standing air conditioner. You will still have to vent it to the outside, but at least it won't hang over a window.

If you don't want to spend the money, you can follow the advice given to me by a Texan: open everything up at night to cool the room. During the day, keep the garage doors closed and use some dark shades to keep heat and light out. When we follow this advice, it's good for 5-10 degrees of lower temperatures. Good luck!

[Wayne77]

Thanks for the info - very helpful. Any idea how much these Sanyo split air systems run?

Maybe the booster fan idea would work as the rest of the house is cooled very effectively (most of the windows are on the back, North side of the house and I would be willing to give up a little of the cool air in the lower levels to cool the bonus room). I'll look into it.

Free worthless advice , you should :
install an attic fan to suck that traped air in the attic out of the space.
install boster fans in the ducts that delver air to this space, bear in mind that this will ROB air from other rooms in the house
better yet install a Sanyo split A/C system in this space and like my brother keno says Forget about it !!!

These Sanyo systems are attractive and will do the job with minimal intrustion of your space and they are quite. Not the cheapest fix but they work great. I assume your garage is not cooled either and your issues are compounded when you drive your warm car into the garage below. I have a A/C garage and two rooms above this space thats 24 by 24 and I have 2 tons of cooling dedicated to this area , mainly the rooms above with only 2 bleed registers to temper the garage if that helps you any.

Yes I am a professional engineer and i work in the HVAC field .

[Smiley]

any HVAC supply house as well home depot sell in line round duct boster fans , you can transition these round ducts to retangualr sheet metal openings , you can power these fans up with 120 volt line current like a light bulb. I'd try this fix first since your other rooms are fairly cool, have you tried re-balancing the dampers/registers to each room to allow more air to the hot zone if this has not worked then the fans will do the trick . Smiley

[Ken Robb]

When one has a hot space the obvious first thought is to increase the cooling thereto. Less obvious is to reduce the heat load. Are your attic above and garage below insulated? How about the ceiling/floor between garage and tv room? If it's HOT outside and you want to cool this room in the afternoon a whole-house fan isn't going to help much.

[Wayne77]

When one has a hot space the obvious first thought is to increase the cooling thereto. Less obvious is to reduce the heat load. Are your attic above and garage below insulated? How about the ceiling/floor between garage and tv room? If it's HOT outside and you want to cool this room in the afternoon a whole-house fan isn't going to help much.

The exterior garage walls are not insulated but the floor between garage and tv room is. The attic above is insulated as well. I think the problem is more that the hot air is rising to the highest point in the house (or forced there by the incoming cool air from vents lower in the house) with no where to go. There are air return vents in this room but they are placed along the baseboards by the floor so I don't think they are efficiently sucking the hot air out of the room which is closer to the ceiling. You can literally sit down on the couch and then standup and feel the hotter air about 4-5' off the floor.

Interestingly enough, the problem is worse in the evening when the lower part of the house doesn't need as much ac so the ac isn't running at all. I can crank it up in the evening but then the rest of the house is an icebox. In the afternoon when its hot outside and the ac is running the tv room isn't as hot.

I'm going to try adjusting vents elsewhere in the house then the vent booster fan idea and then possibly the Sanyo dual zone thing. If that is too cost-prohibitive I'll wait until next year when I can finish off the basement for a REAL home theater room...

Thanks for the ideas everyone!

[Ken Robb]

return grills near the floor are good for heating and that's more important in most areas so that's why they are put there. You may be able to get better balanced temps through the house by partially closing the ducts in the rooms that get too cold when you are happiest upstairs. Ceiling fans can help a lot curing the stratified temps in your tv room.

[davep]

I had a similar problem when I moved into my house four years ago. I ended up getting a mini-split system. Not Sanyo, but it works pretty well. Its called a Goodman, and it is probably a Sanyo, Mitsubishi or something similar under the cover. The remote control is rather flaky, but it does cool the room. I believe I paid about $1,500 installed, and that included installing a new 110v circuit. Its a pretty good sized unit so it's not that inobtrusive, but it is pretty quite.