Ceiling fans needed?

[Burl]

Does anyone use ceiling fans with radiant heat? My garage is 30' X 32', 12' ceiling, (will be) R13 in the walls and ceiling, R17 in the doors (2). I'm just mapping out my electrical stuff, should I include a couple runs for ceiling fans? I know that radiant heat "heats" objects, but will the "heat" rise to the ceiling, as in other systems, and stay there? They'll be no A/C, so any fan wouldn't be used in warm weather.

 

[drivinhard]

I think in my shop (12' 4" ceiling) a high mounted fan would push some heat down. The heat really takes off to the top. This is great in the summer, as the work area stays really cool with the AC on.

I had to hang some banners yesterday and was up on a 12' ladder, it was chilly, I had the heat on, it was 60 down on the floor, and felt like 90 up at the top of the ladder. I was pouring sweat. Anything to help push that down has gotta help...

 

[Stuart in MN]

With infloor radiant heat you shouldn't have a problem. As you mentioned, it heats the objects in the room and not the air, so it really should be cooler up at ceiling level.

 

[kbs2244]

Put them in.
Infloor radiant does heat "objects"
That object is the floor.
The floor heats the air and warm air goes up.
At the celing radiant heats objects also.
And they radiate that heat into the air.
Put fans on low speed, blowing up, and never turn them off.
They will even out the heat and help dry off the cars.

 

[Stuart in MN]

Think about how radiant heat works. It doesn't heat the air, it heats the objects in the room. If you have a hot stove, it's hotter the closer you are to the stove, and when you move away it gets cooler. Same thing with infloor radiant heat; the floor is the warmest part of the room, and as you get closer to the ceiling the air temperature goes down. A fan won't be needed for heating purposes, although it would be nice for the summertime and/or to help dry off cars as mentioned.

 

[Charles (in GA)]

Ceiling fan thread you might find of some use.

http://www.garagejournal.com/forum/showthread.php?t=11627

Personally, I prefer that fans blow down all year. In the summer, both ends of my building (steel building) are open and the fans blowing down bring down trapped heat from near the roof, and the wind carries it out, plus I get a breeze from the fans. In the winter, the fans can grab hot air from up high, and push it down to the floor. This seems to work much better than expecting a fan mounted 15 ft high to somehow **** cold air up from the floor and displace the hot air. The blow up theory might be functional in a regular 8ft house ceiling and rooms, but not in a high shop, or one with open trusses and no ceiling.

Charles

 

[Oldram__Newram]

I have hydronic radiant with a 14’ ceiling height. I have a storage loft in one corner so I go up to ceiling height often and the temp feels amazingly even all the time. I also have ceiling fans, when I run the fans on low the room temp is consistently about 4 deg. closer to the slab temp, but due to the breeze it actually feels cooler with them running. Lately the only time I turn them on is when I have the auxiliary propane heater running to blow the hot air back down. I think the fans will be very nice on the hot summer days.

For the minimal cost of wiring and a few electrical boxes, just plan for them now. You can always add them easily afterwards if you decide they are needed.

 

[kbs2244]

My argument for having them blow up is that the air flow goes across the ceiling and down the walls.
You do not get the local strong air movement.
You get a more spread out movement.
This will make sure you have circulation around anything stored against the walls.
That keeps the stuff dry and mold free.
Having the doors open will mess up that circulation.
But even the most heavily used shop will spend more hours closed up that opened up.
And the air path re-establishes itself in about an hour.
But this only works with flat ceilings.
With vaulted or open trusses I go with blowing down.