radiant tube heaters

[scottj owen]

I noticed in a forum that a poster said to stay away from radiant tube heaters because they caused shrinkage. I was just thinking of putting one in my shop, has anyone else had these same problems. I thought they would be great because the have a fresh air intake and wouldn't blow dust around the shop. They are also alot more efficient than a furnace. Thanks.

[scottj owen]

Just wanted to clarify that I have read all the previous forums on this topic, but am looking for experience involving the effects on equipment and materials. Thanks again.

[Jim Becker]

The only heat in my shop is radiant...and I mean overhead, although small electric units. The only concern I would have relative to the big gas-fired units is that you have at least the minimum ceiling height for the particular product you are considering. I can't imagine it hurting equipment and materials if it's not too close and I suspect it would be physically uncomfortable for "you" if it were too close, too. Now, I'm speculating here, but again, if installed properly I'd not be personally too concerned.

[Jim Andrew]

A friend of mine has the gas fired radiant tube heater. His shop has a high ceiling and not a lot of insulation, it's concrete wall panels, but he likes it fine. If you are talking about wood shrinking, it is probably getting dry because of the heat. Jim

[Wayne Watling]

Scott,

I installed a radiant gas heater just prior to last winter and the heat from these units is beautiful. I've read that some woodworkers can find the heat uncomfortable but I've yet to experience that and I do work close to the heater at times. It has a thermostat which is set to around 10 deg C and gets notched up to around 15 when I enter the shop, so the shop is really cosy whenever I'm in there and the heater doesn't stay on for long to get the room up to 15. I think the reason why is that the shop is well insulated and everything stays warm and retains the heat. Actually come to think of it, its not that often that the heater starts up when I'm in the shop and I'm sometimes in there for 3-4 hours at a time, so the key is good insulation which leads to good heat retention.

Being a hobbyist woodworker I don't do near as many projects as a pro but I've yet to experience any problems related to wood shrinkage but just to be sure I always try to store any current projects away from the direct rays of the heater. If you store all the wood for any one project or parts thereof together in the shop they would probably expand and contract at near the same amount anyway (all things being equal and depending on type of wood and thickness etc). My shop has 9' ceilings and the heater is right at the minimum hight from the ceiling required by the manufacturer.

Best,
Wayne

http://i97.photobucket.com/albums/l227/woodworkingpics/Radiant%20Heater/DSC01919.jpg

[Doug Swanson]

Wayne,
Thanks for the info. I have a similar unit hanging in my garage (space ray 50k btu)...I'm waiting on my plumber to pressure test the gas line and vent it...I am glad to hear you find this heater to be a great choice...I went back and forth on what type of heater to get (since I couldn't do radiant floor heat)...and settled on the gas tube heater...can't wait to get it hooked up...it's cold and snowy in MN right now..

Doug

[Al Willits]

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They are also alot more efficient than a furnace
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I'd be interested in what your figures on that are?

Al

[Rick Christopherson]

These radiant tube heaters are great in a garage. The problem with using them in a woodshop is if your lumber pile is in direct line of sight to them. The heater will heat up the surface of the wood and cause it to dry out. This can cause some of the wood to get excessively or unevenly dry.

[Wayne Watling]

These radiant tube heaters are great in a garage. The problem with using them in a woodshop is if your lumber pile is in direct line of sight to them. The heater will heat up the surface of the wood and cause it to dry out. This can cause some of the wood to get excessively or unevenly dry.

I suspected that something like this could happen and tend to keep the wood at the side or end of the shop while milling or assembling in particular, again I've yet to actually see any problems. The heater itself rarely comes on while I'm in the shop and when it does its only for 10-15mins at a time, I'm not sure this would have much of an effect on the project I'm working on. Before leaving the shop I make sure any projects are placed away from direct view of the rays. Wouldn't you get a simular effect if hot air was blowing onto the bare wood surfaces?

The total cost of gas from the beginning of last winter until now is CAD $689, the tank is currently 35% full.
The shop is 21 x 23 x 9'
Insulated with R21 walls and R31 in ceiling
Wooden floor with insulation around the sides that back onto external walls.
Garage door is uninsulated, there are small gaps under 1 door that leads to a mud room and there are a few small gaps around the garage door itself.
Location: Slightly north of Toronto, ON Canada.

[Rick Christopherson]

Wouldn't you get a simular effect if hot air was blowing onto the bare wood surfaces?
No. A convection heater heats the air, so the air will be whatever temperature you set the heater for. A radiant heater heats the objects in a room, which in turn heats the air. As a result, the objects need to be hotter than the air in order for them to heat the air.

Next time you turn on the heater to begin working, lay a piece of wood out on your saw and feel the temperature of it when the heater turns back off. You should notice that it is quite warm.

I don't know that there would be a risk to your projects because it is short term. The primary concern is a lumber storage rack that gets direct heating over a long period of time.

[Wayne Watling]

[quote=Rick Christopherson;728812]No. A convection heater heats the air, so the air will be whatever temperature you set the heater for. /quote]

The fact that the radiant heater heats the actual objects is what helps everthing (the big iron) stay warm for so long which in turn helps with efficency, a bit like a heat sink effect. If possible locate your rack off to the side of the heater, none of my supply ever gets overly warm, I doubt it would have any effect unless the wood rack was located directly in front of the heater rays.
I'd have to say I dont get why this would not happen if you place the same wood rack in front of a hot air blower, the hot air would dry one face of the wood and cause the same problem.

[David G Baker]

If you have a concrete floor the radiant heater will also heat the concrete and help hold the heat in your work space.
I have a 75 K Modine Hot Dawg ceiling mounted forced air heater. I keep my 30'x40'x10' pole barn at 50 degrees in the cold months and turn the heat up to 65 while working in the building. The difference in the two types of heat really shows up when handling metal. Metal items in my building will cause my hands to hurt from the cold. If I had radiant heat, every thing in the building would be comfortably warm if the heat was left on 24-7 and probably would not cost any more to run than my heater.
Another advantage that the radiant heaters have over my forced air heater is the use of out side air for the air source. My shop smells pretty bad after not using it for a few day.
Insulation is the key to efficient heating and cooling.