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SMO
12-02-2010, 10:40 AM
I have purchased a property that has a ~1,000 square foot shop (12 foot ceiling). It has natural gas to the building but no furnace. I am waffling between going with an overhead forced air furnace or using radiant tubes hung from the ceiling. Cost of either system is about $1,000.

I am leaning toward the radiant tubes, but some folks tell me I will not be happy with these because they don't warm up the air. Can anyone with experience with the radiant tubes give me any guidance?

I want to keep the shop temperature at ~60 F minium year round, it can get to -25 F in the winter.

rocketbob
12-02-2010, 10:53 AM
If the shop is insulated well, go with a furnace. If its not insulated, go with radiant.

Paul K
12-02-2010, 11:01 AM
I have a very well insulated building, 10" blown in the walls and 24" blown in the ceiling, and have radiant tube heat. Even on a cold Michigan winter night, I can work in a T-shirt and over a 3 hour period, it may run for 5 minutes, once!

I found the tube system used from the paint line at an old autoparts plant, got it free!

CZ75shooter
12-02-2010, 11:54 AM
I live in Georgia, so cold for me is 30 degrees. I have a 1600 sq. ft' insulated shop and heat with one radiant tube heater. The way the heater guy explained it to me was the radiant heat is like standing by a campfire. You can feel the heat but it doesn't heat the air between you and the fire. So the rediant heater heats the floor, you, the tools, and your project. The objects in the shop then heats the air. When you open the door you may lose less heat to air loss and through leaks I really like mine, have you ever bumped your cold stiff hand on a cold piece of metal with a cold wrench?
Larry

Mitch757
12-02-2010, 11:58 AM
I have a 44' by 40' insulated hangar and use a Space Ray natural gas tube heater. It is 75k BTU and will bring the temperature up to a working temp (from 30 degrees or so) in about an hour or so.

Now I just keep the temp set at 50 and it is comfortable very quickly.

My only caution would be if you had a fabric airplane placed near the radiant pattern. I would be concerned about the local heating then since it heats "objects", not air.

I am very pleased, especially since I got an energy rebate, making the cost around $600.

Mitch

RV4 flying

Andrew M
12-02-2010, 12:00 PM
I really like my shop/garage with radiant heat. I built the house myself, and installed 2" of blue board insulation under the slab. Adding radiant by pouring on top is doable, however the local contractors up here recomend adding the insulation under the pour to minimize the amount of heat lost to the ground. We typically see zero to 10 below with occasional cold snaps to 40 below. The air stays plenty warm as cold air falls and is heated, where "blower"' type systems will leave alot of the heat near the ceiling without a fan. Plus warm feet makes for real comfort.

David Paule
12-02-2010, 12:09 PM
It's a no-brainer: go with the radiant heat. You'll be MUCH more comfortable.

Good insulation is another issue. Make sure the walls and ceiling are very well insulated, foam is worth the money (it stops tiny leaks). Out here it costs about $.85 a board foot so it's a bit pricey. My shop has batt insulation in the walls, foam in the roof (no ceiling) and is quite comfortable. The hangar, with only batt insulation is decent but not as good.

The hangar, incidentally, has forced air heating - much less comfortable than the radiant heat in the shop.

Noel Simmons
12-02-2010, 02:13 PM
I have tubes in the floor, LOVE the radiant heat.

1000 seems a little light by twice.

N8RV
12-02-2010, 02:50 PM
I have a huge GFA prehistoric monster (the nameplate says "Bedrock Smoke and Fire Company, Ltd.") that belches out 200,000 btu to heat my 30' x 44' hangar. The hangar is insulated, but not as well as I'd like. I keep it set at 40* from late November till spring, and it seems to work well. When that sucker kicks on, it's loud and blows a lot of nice, warm air. Only takes a few minutes for the temp to get toasty. And the clicking sound from the gas meter as the hands whirl around has a beat you can dance to.

However, because I'm sure it has an efficiency rating of something like 5%, I've contemplated replacing it with a more efficient, modern unit. I hadn't considered radiant tube heating.

Since it heats objects instead of the air, I'm wondering ... are there any deleterious effects of radiant heat directly over a canopy?

Doug Lewis
12-02-2010, 05:20 PM
A friend who owns an HVAC company insists radiant tube is the only way to go in most shops for efficency and effectiveness. The installed price is nearly identical. I have forced air in the current shop which works fine, but when the other side's done it'll be tube.

L.Adamson
12-02-2010, 05:26 PM
I'm in the heating & A/C trade. Have been for 40 years. Last year, we removed the radiant tube from a friends large hangar, and installed a hanging forced air unit heater. It heats a lot quicker, and he likes it better.
He also runs the double fans in the summer to move air. Time to heat, using the radiant tube.........was his main complaint.

L.Adamson --- RV6A

pat
12-02-2010, 06:45 PM
I have a 42 x 42 well insulated hanger. I have a radiant tube running about 12 feet from the side wall running the length. I have the project placed underneath and my other toys on the other side of the hanger. while working I can easily work in a T-shirt during any cold winter day (michigan). I would quess a 15 degree difference on the other side of hanger but still very comfortable. Heats quickly and no dust blown around. 14 foot ceiling. hope this helps.

AlexPeterson
12-02-2010, 08:56 PM
A guy here rolled his RV4 from the cold outside into a hangar with the ceiling radiant heater running. Canopy cracked as the radiant heat probably heated it too fast. Maybe that is very unusual, but would scare me off. To each their own.

GrayHawk
12-02-2010, 09:58 PM
Recently I was looking into what type of heating for my hangar at 5060' elevation, Colorado winters.

This is very second hand, word of mouth rumor, cannot provide any data:
Some hangar owners with mainly 'glass' planes install electric convection style heat as radiant and 'glass' do not mix??

I have natural gas available but am looking at a heat pump system.

L.Adamson
12-03-2010, 01:48 AM
I have natural gas available but am looking at a heat pump system.

Heat pumps don't work well, when the temps drop (30 degrees F & below)..........and rely on backup, whether it's natural gas or electric resistance. Unless electricity is real cheap compared to gas..........they are not the way to go, for cold winter installations.

L.Adamson --- RV6A

Bob Martin
12-03-2010, 05:25 AM
This is very second hand, word of mouth rumor, cannot provide any data:
Some hangar owners with mainly 'glass' planes install electric convection style heat as radiant and 'glass' do not mix??

If you look close at the "tube" type radiant heaters install info, they have a paragraph on "aircraft hangars". They show a minimum clearance of 10' vertical from the tallest part of the airplane. I called the manufacturer about this and they were very serious about that spacing and said the radiant heat could discolor paint, etc.
I have a 42x42 steel hangar and could not get 10' clearance above a high wing airplane. Even trying to install it between the steel trusses in the peak.
Our FBO shop is huge and uses the tube type, but they are very high!

N8RV
12-03-2010, 07:42 AM
If you look close at the "tube" type radiant heaters install info, they have a paragraph on "aircraft hangars". They show a minimum clearance of 10' vertical from the tallest part of the airplane. I called the manufacturer about this and they were very serious about that spacing and said the radiant heat could discolor paint, etc.
I have a 42x42 steel hangar and could not get 10' clearance above a high wing airplane. Even trying to install it between the steel trusses in the peak.
Our FBO shop is huge and uses the tube type, but they are very high!

That's what I was wondering, Bob. Good info. My hangar ceiling is probably only about 12 feet (I'd have to measure it to be sure), so obviously putting a tube near the ceiling would not give the required clearance between it and a canopy.

I would imagine that a more efficient GFA furnace would be a good replacement for Ol' Blowtorch when his final day comes. Unfortunately, my local heating/cooling/pilot guy quoted me something like $2500 for one. I can buy a lot of gas for that ...

GrayHawk
12-03-2010, 07:59 AM
Heat pumps don't work well, when the temps drop (30 degrees F & below)..........and rely on backup, whether it's natural gas or electric resistance. Unless electricity is real cheap compared to gas..........they are not the way to go, for cold winter installations.

L.Adamson --- RV6A
Depends on the type of heat pump (ground source, air source), its efficiency, insulation, and how much heating/cooling you want. Also there are many other considerations: no combustion, no roof penetrations (exhaust), less danger, one utility bill-not two, ease of install, ease of UN-install, etc... the list goes on & on.

Would not have a backup as I have nothing right now, .... but then as I said, I am just looking at it.

Steve N.
12-03-2010, 08:22 AM
I installed a Reznor 100,000 btu gas heater (82% efficiency) in my 45' x 56' well insulated hangar. The walls are 6" S.I.P.'s (structual insulated panels) with a metal ceiling and 12" of blown in cellulose. I keep it at 55* then raise the temp to 65* when I enter. It takes about 5 minutes to warm up then runs only occasionally throughout the day. Temps here in north central TN this time of year typically drop to below freezing, sometimes in the teens, then warm up during the day. I like the ability to be able to raise the temp quickly and have very little variation in temp at any location in the hangar. The unit is installed in the back corner just below the ceiling above the restroom, so it does not get in the way if you have something tall to move around.

jaybell
12-03-2010, 03:25 PM
I have had three systems, forced air which I liked the least, heated floor which I like the best for performance, and radiant tube which I like the best for combined performance and low cost installation.

The radiant tubes heat objects such as people and airplanes, not air, which is the whole point. I found the forced air unit blew too much dust around, especially when I was welding a tube and fabric plane.

You can try the radiant tubes before you buy for free by taking in a hockey game at the local arena.

Jay

SMO
12-03-2010, 03:52 PM
Glad to get all the comments on this. For clarity, the shop is well insulated and the radiant tubes I am talking about are the ones that hang from the ceiling. If I were building a new shop I would use in floor heating even though that option is more expensive. But I already have a good cement floor and I am not about to jack hammer it out, and I am not inclined to add more inches elevation to it.

Reading along I was just about convinced to go with the tubes, but the comments regarding the proximity of the tubes to the canopy has me concerned enough I will probably go with forced air despite its drawbacks.

L.Adamson
12-03-2010, 06:30 PM
Depends on the type of heat pump (ground source, air source), its efficiency, insulation, and how much heating/cooling you want. Also there are many other considerations: no combustion, no roof penetrations (exhaust), less danger, one utility bill-not two, ease of install, ease of UN-install, etc... the list goes on & on.

Would not have a backup as I have nothing right now, .... but then as I said, I am just looking at it.

Very true. A ground source system has a much better chance of working during those cold days. However, in most cases, it will also be awful expensive. Far more than a radiant tube or forced air unit heater. More to go wrong....too.

As to ---in the floor...........it's very nice. But it's also expensive for the boiler, pumps, manifold system, and water heater if desired. And while a hanging unit heater will only take a short time to heat the shop from 50 to a comfortable 68 degrees, a boiler operated floor system would take much longer.

That's something one must consider. Do you want to maintain higher temps all day long, or just boost them higher when you go to the hangar to work on the airplane. Setback t-stats can also be considered if you know when you'll be there, and when you won't. Otherwise, a forced air gas heater, is the fastest of them all, when it comes to heating quicker.

Note: heat pumps are also slower for recovery. The outlet temps are lower than gas fired. But you do get air conditioning with it. And that brings up another question. Do you want use refrigerated A/C for the whole hangar? Nice, but it can cost a lot to operate, especially with large doors opening and closing a lot.

L.Adamson ---- RV6A

TroyBranch
12-03-2010, 08:56 PM
Your ceilings are to low to make radiant heat the better option. You will feel like you are baking under them. I have radiant in the hanger that are 18ft up in the air and still gets quite warm if you are working under them. The higher the better. Forced air will be a bit louder but you will not have to worry about cooking your canopy or fiberglass that could get to close to the radiant heater. My garage is 1100sqft with 16ft ceilings and the 60k btu forced air keeps it plenty warm even during a cold Alberta winter.

RWoodard
12-03-2010, 09:32 PM
For what it's worth...

I've got a 75,000 Btu forced air heater in my 950 sq. ft. T-hangar. I've lowered the ceilings to 10 feet using a combination of acoustic tile hanging ceiling in the front half of the hangar and a sheetrock ceiling in the back part of the hangar. All the walls are also drywalled and everything has R-13 insulation. I even insulated the bi-fold door with R-13.

I keep the hangar at 40 degrees all winter when I'm not there and then kick it up to 60-63 degrees when I'm working. I like to keep it a bit cool because I'm usually working in a sweatshirt. (Heck, I keep my house at 65 degrees--yes, I'm single!) The highest bill I had last winter when I was working 30+ hours a week at the hangar was about $70. That's pretty reasonable as far as I'm concerned when we're battling some pretty chilly daytime high temps in January and February.

I'm very happy with my Modine "Hot Dawg" heater. It requires very little clearance from combustibles. I ordered it online and paid somewhere around $500 for it (6 years ago). I installed it myself using 4" double-walled exhaust pipe straight out the top of the hangar. I had a "professional" run the natural gas line. Wish I would have done that myself, too, after seeing the quality of the work!

Happy heating!