Radiant heat questions

[SteveU]

Gas fired Radiant tube heat questions

How long does it take to get things warmed up with a gas fired radiant tube heater? I have a 40x48x14' barn with insulated sidewalls & ceiling but no insulation in the slab. Is it better to run these all the time to maintain temp or can they be fired up when you want to do something out there? How many tubes would I need to install for the 40' width? What is the operating cost of these compared to oil or propane forced air? Do these raise your insurance on the building? Is it necessary to install ceiling fans like with hot air type heaters? What is the longevity on these systems? Is installation a do it yourself operation assuming fairly proficient person or is it a professional only operation? I have installed gas water heaters so it isn't more difficult or technical than that is it? One of the problems I have is in the spring when the slab & everything else is cold & the warm moist air comes in making everything sweat, would these help with this?

 

[5wndwcpe]

Boy Steve you ask alot of questions... first off, you say the slab isn't insulated. So am I to assume you're proposing to lay your tubing and pour a thin slab over your existing floor ? In any event, the link below will provide you with the Zurn radiant heating design manual. It's long but it contains all of the relevent information you need to know in order to design an efficient heating system.

http://www.zurn.com/images/pdf/ZPM02101.pdf

 

[GaryRoushkolb]

I've had floor heating in my shop for about 4 years now and love it. I leave the thermostat set at 57 degrees about 30 inches from the floor. The system is always on and when it's summer the water just circulates. The most important thing is lots of wall and ceiling insuulation , I have R30 or 8" on both the walls and ceiling. it's so good that you can't hear rain on my metal roof. I use a boiler for my heating source but a large water heater will work great also. The best part it only comes on about every 2 hours and then for only about 10 minutes. This if the best thing Ive ever done to make the shop workable all year round. Just set it a little cool when you first get there and in about 10 minutes your ready to get down to a t-shirt. I have a 10 foot ceiling and a loft in the front to clear my lift and I put a ceiling fan there and leave it run all the time also. No floor sweat in the spring and fall also and I use a dehumidifier in the summer to knock down the dampness of our climate.

 

[SteveU]

I was thinking more of the gas fired tube heaters that go on the ceiling, not the in floor type. Sorry for any confusion.

 

[5wndwcpe]

Duh, after re-reading your o.p. it makes sense now.

 

[Franz©]

The tube will reach operational heat in seconds, burner end around 1500° and remaining tube depending on length will be radiating 15 seconds later.

Using them in the only when you're there situation you'll be warm but everything you touch will be cold for a few hours, metal warms up slowly and the heavier the metal is the slower it warms.

Installing, well, contractors use 18 year old pimple faced kids to do it, so if you're smarter than the average kid you can install it. CoolRayVac tends to be a bit snotty about selling their product to anyone not a dealer but there are at least 4 other makers. If you can read a level and an instruction sheet you should be able to install.

Insurance, the units carry UL approval, so insurance shouldn't be an issue.

The units DO require maintainence in shops, especially if they are drawing combustion air inside of a dusty shop.

NO, it won't hepl your condensation situation. What will help that is a small exhaust fan near the roof sized to keep a constant flow of air thru the building. You will also need to have a sourse of makeup air so the building doesn't go negitive pressure. Fortunately, that combines nicely with radiant tube heat and minimizes heat loss.