Please Educate Me on Infrared Heat (LPG)

[MisterMike]

My situation: Our second home will hopefully become our primary residence in the next couple of years. It's located in SW Wisconsin.

We have a 30x48x14 pole shed that's very well insulated with closed cell foam. The walls are finished, but it's open to the trusses (roof is also insulated). We use it for storage of equipment, a garage, and a party space for an occasional hootenanny. For reasons known only to the gods, in winter the interior temperature hovers around 25-30 degrees above the outside ambient temperature (it's completely draft-free, and I'm guessing that the thermal mass of the concrete, gravel base and ground, combined with excellent insulation, help moderate the temperature).

We're on LPG. Natural gas is not an option and our electrical rates are pretty high. I'm not interested in keeping the building heated 24/7, only having the ability to heat it when I'm working out there or gathering with family and friends on a cold day. It seems to me that LPG-fueled infrared heat is the right answer for my situation.

Is this sound reasoning? If so, what type of equipment should I consider, and what design attributes should I be looking for?

The tube heaters seem to me as though they'd be a good solution for this type of application, a la this type of design:

Or, would I be better off with a two or three units like this:

Good brands? Bad brands? What else am I missing?

Thanks in advance.

 

[gungatim]

GordonRay makes a good commercial unit. they are not cheap. I have one I bought as a used take-out from a shop but had the pipe cut off and missing. replacement aluminized steel or stainless pipe and reflectors would put me in the $800-$1k range, completely eliminating the awesome deal on the unit to begin with...

but they are nice, they heat people/objects not the air, so it will get you warm quick if you are not running it 24/7...lots of shops/warehouses use them for heat where heating a huge expanse of air is not needed/cost prohibitive...they are also extremely customizable. hang the unit, then snake the pipe wherever you want it, straight, L, U, etc.

 

[MisterMike]

I believe(and refused to believe before I did the math) that a pound of propanr burned produces 8 pounds(might be six, gasoline is 8) of water.

Good info. Certainly something to factor into the decision. I don't know that it would be a problem with my contemplated level of usage, but I'll have to noodle this over.

 

[MisterMike]

Propane is 1.65 lbs of water per pound of propane burned.
Sorry.
I had the gasoline numbers....

Gotcha. Thanks!

 

[Fueler]

What is with the water scare?
To the OP. My pole barn is similar and I use the Tube style on propane. Works very well.

 

[Bruce Amacker]

Open burner (non-vented) units give off tons of water vapor which condenses on your nice clean motor/tools and rusts them. OK in a warehouse/loading dock situation where the rollup doors are open a lot, bad in a closed shop environment.

Tubular vented works well but must be about 15' up- I have one right now that's 11' up and will burn/melt paint if an SUV or van is left under it. I experimented and put a piece of Vette FG under it at about 4' up and it blistered the paint on it when left on high. Go with a power vented unit. I built heat deflectors for mine to prevent damage to cars.

Personally I like gas forced air best, I put two new ones in lately. One shop has both GFA and tubular, I only run the tubular occasionally. I bought two GFA lately off of CL for $100-200 each in excellent condition. If you don't know what to look for, go by the build date and check the heat exchanger for age/cracks/rust with a flashlight.

Good Luck!

 

[Tim C]

We have the Dayton units at my work in NC. They are on natural gas but the LPG should heat similar. There are 6 total heaters in a 100' x 30' shop which has five bays. A roughly 30-40 x 30 section of the shop has no bays but is used to store equipment and stock such as oil filters. Each of the five bays has a 30000 btu Dayton like your bottom picture centered in front of it opposite the bay door. Each of us mechanics has our toolbox and workbench under one. Granted it doesn't get cold in NC like other parts of the country but we can come in on a mid teen morning and the building will be in the high 40s. We usually run four units for about two hours. After an hour run time the building is warm enough I usually pull off my jacket and work in short sleeves. After two hours we usually turn off two or three of the units. One guy is cold natured an runs his all day long. Mines off after two to three hours and I'll occasionally flip it back on of someone has opened a door for a long period of time. If the morning low is between 30-40 degrees we only run one or two heaters initially. Ours are about 6' in front of the bumper of a car if its lifted. I've never seen a car damaged by the heat nor noticed any rust on my tools not that I doubt the above posters advice. We did have a guy that hangs out every afternoon sit under one for three hours on a stool one day and his hair started smoking LOL

Sent from my XT1254 using Tapatalk

 

[Fueler]

I just don't have any humidity problems created by the tube heater. I have a lot of machining equipment with exposed tables that I take pride in. IF I had an issue there I would certainly be all over the net decrying that propane is bad thing.

I just checked. 67.6 degree, 33.8% humidity. Actually too darn dry for my tastes. I don't know where others are getting this rusty equipment issue but it is not coming from my tube heater.

If there is a humidity issue it would have to be with the exposed square grid type. I just don't see it with the enclosed tube setup.

Come to think of it that would be correct.
I installed one of those grid type propane wall heaters in the basement of my home. Does a good job but it did indeed raise the humidity so the dehumidifier earns it's keep down there and levels it out. I do believe the instruction sheet even mentioned the humidity issue.

Reveberay brand on my tubes if that means anything.

How hot is it?
I do have a 2 stage system. The high stage only comes on if I leave the big door open for a long time on a cold day like today with the wind blowing. The high side does put out some serious heat but it is supposed to.

Perhaps the 2 stage helps with the blistering issue. I have a hoist and one of the tubes is very near the hoist. I have not had any issues with burning paint on my vehicles when forced to work on them. That is on the low stage to be clear. If for some reason the high side comes on when the big door is open by the time I get the vehicle in and positioned it is back on the low side before I raise it.

Shoot ....if I don't open the big door the unit may fire on the low stage only twice a day.

 

[Bruce Amacker]

Tube heaters don't cause moisture problems, it's the non-vented radiant heaters like this that make lots of steam:

 

[Rockcam]

I am installing a tube heater in my 24' x 45' garage right now.

Tube heaters are a good alternative to in floor radiant heat, as they are far lower installed cost, and obviously don't require tubing in the slab. As stated above, they heat objects like your slab via radiant heat transfer, much like the sun. Go to a Home Depot and you can feel heat from a tube heater at the cash registers.

I bought a tube heater for two reasons. First, I have a 20' cathedral ceiling in my garage, and did not want the heat to just collect up there, while leaving me cold at floor level. Since tube heaters heat the slab, the heat collects at the floor, not the ceiling. In my experience, forced air heaters still leave a cold slab, which leaves you feeling cold no matter the air temperature.

The other reason is I did not want all the heat to escape when we open our garage doors. Because they heat objects vs. the air, recovery is much faster after doors are closed again.

Tube heaters come in both high intensity and low intensity versions. Low intensity versions by manufacturers such as Detroit Radiant allow mounting as low as 8' from the floor, depending on the BTU output. Bruce clearly has a high intensity unit, which may not be the best option for a garage or barn where ceiling height is somewhat limited.

Mine is a two stage unit, and fires at 40K when needed, and 28K BTU when possible. Lots of great posts here explaining more - search "tube heater." You may find you can get a far smaller tube heater (BTU) than you will need for forced air, and be comfortable with a lower set point temperature.

Check out detroitradiant.com. Installed prices were really high ($5K), but I bought mine online at h-macsystems.com for less than a third of that.

Good luck.