# cieling fans with radiant heat ?



## woodsmaster (May 2, 2010)

Hi, I'm building a shop with in floore radiant heat and 14' ceilings. I would like opinions on if cieling fans will help with heating efficency and the amount of insulation to put in attick. I usually go R-60 in an attik but wasn't sure if that much was nessasary with floore heat. It will be 2 x 6 construction. Tried posting this in green room but got no response.
                                                                                                      Thanks J.T.


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## webie (May 2, 2010)

I have radiant in my sun room with a cathedral ceiling and I only see a need for a ceiling fan when I run other forms of heat I have wall heaters and a pellet stove in there also . I find I usually turn off the ceiling fan when just using the radiant as it actually makes it feel drafty , Its kinda hard to explain so I hope you understand . 
 On the flip side I still would put them in just for use in the summer if not the winter . Ceiling fans are really pretty cheap and you can get them with remotes  for operating ease.

Webie


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## stee6043 (May 2, 2010)

A typical radiant in-floor setup should only be heating roughly 6-8' above the floor.  It technically isn't heating the air so the ceiling fan likely will not "help".  Ceiling fans are great in the summer, however.

There are lots of theories on how much insulation is best.  At some point you reach the point of spending more money than you gain.  I haven't heard of too many people in the R-60+ ballpark...


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## heaterman (May 3, 2010)

I don't see the need for ceiling fans unless you install some high velocity types for summer cooling. Ceiling temps will run at or below the wall temps on my infra red thermometer. R-60 would be plenty in the ceiling. Pay attention to door and window seals in that type structure. Air infiltration will cost you more btu's than R-40 vs R-60 in the ceiling.


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## Sorghum (May 3, 2010)

A friend has in floor radiant heat in his shop. Ceilings are probably 12-16 high. I got a few cheap thermometers. I put one on the floor, one about thermostat height, one near the ceiling, and I think one more somewhere in between top & bottom. There was not more than 2-3 degrees difference. I don't recall where it was warmest though.  This was over the course of a few day's in February when they were out of town, so the garage doors would have been closed the entire time. No ceiling fans.


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## woodsmaster (May 3, 2010)

heaterman said:
			
		

> I don't see the need for ceiling fans unless you install some high velocity types for summer cooling. Ceiling temps will run at or below the wall temps on my infra red thermometer. R-60 would be plenty in the ceiling. Pay attention to door and window seals in that type structure. Air infiltration will cost you more btu's than R-40 vs R-60 in the ceiling.



I'm sure the overhead doors will be the weak point in the heat loss. Is there some type of barrior to put in the cement under the door to keep the heat from radiating under the doors ?


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## jimdeq (May 4, 2010)

When you are setting up your concrete floor you could install a vertical piece of styrene insulation across the OH door opening.  Put the styrene on the outside edge of where your infloor tubes stop and hold it down so you can pour at least 3 or inches over the top of it.  This way the tubes will be up against a thermal break.  I would make this at least 10 inches because if your pouring a grade on beam slab you will have a thickened edge anyway.


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## ISeeDeadBTUs (May 4, 2010)

One of my ceilings is~20'. During the heating season, the ceiling fan feels like it cools you instead of driving any warm air down. But maybe the fan is just too fast.

I don't like it hot - like this past w/e. But I usually find that when it's hot enought inside to attempt cooling with a ceiling fan, the air is so humid that the air moving across you skin does not evaporate sweat. I guess in my view ceiling fans are for swinging from only.


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## Der Fuirmeister (May 8, 2010)

Our shop has radiant floor and 24' ceilings.  This past January I shot the temps at the floor, ceiling and areas in between with an Infrared Laser Thermometer.  The concrete floor ranged from 60-62.  The surfaces at roughly 5' high were around 58, and the steel beams at the ceiling were 56.  We have large fans which were used with the forced air heat prior to getting the radiant floor system running.  Now we leave them off.


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## heaterman (May 8, 2010)

woodsmaster said:
			
		

> heaterman said:
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I've seen it done various ways but I have to say i don't recommend a lot of them. Foam underneath cement in a doorway will nearly always lead to a failure of the cement above it from what I have seen. One person laid a 6x6 treated post down in the doorway to act as a thermal break and that seemed to work pretty well. It will be easily replaceable if the need ever arises also. 
It depends on the application but we typically just keep the tube away from the opening several feet to avoid heat loss under the door and ice buildup outside. Very rarely do we come across a situation that needs every last sq ft of floor tubed to provide adequate heat. Keeping the tube back allows the heat to bleed out of the cement before it reaches the door opening.


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