Radiant heat

[Volta]

Anyone familiar with these types of heaters?

http://www.radiantsystemsinc.com/

Warm air rises, but these heaters are installed high on the walls and should radiate out and down.

Are they good enough to suggest using in a roughly 20 x 20' room (I think, haven't seen it yet), lots of big windows, over a porch (exposed on 5 sides)?

It is office space, with exposed sprinkler pipes. It gets cold there, pipes may have frozen once.

Better ideas?

 

[bpk]

They are fairly common in my area. I have installed a few, the compartment to make your connections is usually very small so if you can keep just one wire to each heater it makes it easier. They have worked very well from what I have seen and I live in a pretty cold area.

 

[kwired]

radiant heat heats objects in the room which in turn eventually heats the air.

you mention the room has lots of windows, although I prefer radiant heaters over say a baseboard heater there is a problem with using this type of heater if the heater is going to radiate the heat at the windows. The radiant heat does not stop at the glass it will travel right through and heat the outdoors. This is no different than the radiant heat from the sun traveling through the glass from outside.

 

[ohm]

radiant heat heats objects in the room which in turn eventually heats the air.

you mention the room has lots of windows, although I prefer radiant heaters over say a baseboard heater there is a problem with using this type of heater if the heater is going to radiate the heat at the windows. The radiant heat does not stop at the glass it will travel right through and heat the outdoors. This is no different than the radiant heat from the sun traveling through the glass from outside.

There are three ways to heat things: Conduction like a soldering iron; convection like a hair dryer; and radiation like the heater by Infrared light.

Combinations of them are also possible.

Radiant heaters are good if what you want to heat is: 1) line of sight 2) dark colors (white reflects the heat).

It sounds like a good application and the height should not matter. Sensitive electronics should be shielded from the IR heat.

 

[rfwells]

There are three ways to heat things: Conduction like a soldering iron; convection like a hair dryer; and radiation like the heater by Infrared light.

Combinations of them are also possible.

Radiant heaters are good if what you want to heat is: 1) line of sight 2) dark colors (white reflects the heat).

It sounds like a good application and the height should not matter. Sensitive electronics should be shielded from the IR heat.

The "white reflects heat" thing is somewhat an urban legend. What appears white does so because it reflects light in the visible spectrum. Visible spectrum is not IR, and you can't generalize from what your VSR's (visual spectrum radiometers, aka eyes) pick up.

I have vintage 1964 electric radiant ceilings, which is a heating cable snaked across the ceiling every 4.5" in a 1/2" drywall sandwich and a toadload of blown in on top. It works beautifully - noiseless and maintenance free, warm surfaces, no fear of blocking a vent. But. No can lights.

 

[Volta]

Looked at the place today, still feel that the heaters will work for the occupant, but the sprinkler line is not exposed, rather it is above acousical tile, above insulation, above gypsum board, and no heat in sight.

I talked to the structural (sprinkler) inspector, and decided / read that while heat tape is legal, it must be listed for the application (fire protection branch) and supervised by the FA system. That will bring the cost up.

They can gain some heat retention with new weatherizing, but if we can find some other heater safe to use in the tight space, not in contact with the pipe, it can save them a chunk of money.

Any other ideas? One section (the coldest) may only have 8" or so vertical clearance.

 

[winnie]

Dry sprinklers?

This is a sprinkler system that is filled with air. If a sprinkler head opens, then the air pressure drop causes a valve to open, and water flows through the system. This is a standard solution for freezing sprinkler systems.

-Jon

 

[Volta]

Dry pipes

Dry pipes

Might be best, and they do have them in the building. In fact I did leave a voice mail today saying that might be the best move, not the cheapest, maybe, but might be the best. They would have to pay for engineered drawings, $500 for permit, then the work itself.

Even with a tight budget though, it may be their best option, in the long run.

Even some other heat I install doesn't have to be supervised per code, if the heat is needed, it still should be.

Thanks.

 

[ohm]

The "white reflects heat" thing is somewhat an urban legend. What appears white does so because it reflects light in the visible spectrum. Visible spectrum is not IR, and you can't generalize from what your VSR's (visual spectrum radiometers, aka eyes) pick up.

I have vintage 1964 electric radiant ceilings, which is a heating cable snaked across the ceiling every 4.5" in a 1/2" drywall sandwich and a toadload of blown in on top. It works beautifully - noiseless and maintenance free, warm surfaces, no fear of blocking a vent. But. No can lights.

I was refering to Black Body Radiation where the emissivity of of an object approaches 1.0 This is the point where an object (blacK) becomes a perfect absorber and emitter of radiation. A good explaination is found at:
http://www.electro-optical.com/bb_rad/bb_rad.htm

 

[ptonsparky]

As with any type of heat the room needs to be insulated well. Lots of windows mean lots of cold air currents from the windows even if they don't leak. Shaded areas under desks will be colder although the top of your head will be toasty.

 

[ohm]

Looked at the place today, still feel that the heaters will work for the occupant, but the sprinkler line is not exposed, rather it is above acousical tile, above insulation, above gypsum board, and no heat in sight.

I talked to the structural (sprinkler) inspector, and decided / read that while heat tape is legal, it must be listed for the application (fire protection branch) and supervised by the FA system. That will bring the cost up.

They can gain some heat retention with new weatherizing, but if we can find some other heater safe to use in the tight space, not in contact with the pipe, it can save them a chunk of money.

Any other ideas? One section (the coldest) may only have 8" or so vertical clearance.

Can the insulation be cut where the sprinkler lines are run to allow heat from the room to keep them from freezing? A few ceiling mounted vents could be cut into the ceiling tile if need be. Pick a cold day to measure if enough heat is escaping the room by taping a thermometer to the pipe.

 

[Volta]

Can the insulation be cut where the sprinkler lines are run to allow heat from the room to keep them from freezing? A few ceiling mounted vents could be cut into the ceiling tile if need be. Pick a cold day to measure if enough heat is escaping the room by taping a thermometer to the pipe.

Maybe. Some plenum return tiles might help a lot, with removing the gypsum.
They put the insulation there 'cause the occupant was cold, but the radiant or other room heaters could make up for the difference.

They had a probe on it when I got there, ranged from 57 to 63 deg. F. That wasn't the coldest section, the adjacent was more like the 40's with tiles open and heaters on the floor. Definite cold air movement, they need to recaulk and insulate.
That may be a good solution if it can look good enough.