Radiant heat vs Electric Heat

[Chris Damato]

Hello,

I am looking for some advice on heating my garage shop. I just had the garage walls and ceiling insulated with a "blown in" insulation. Just the insulation has made a difference in increasing the shop temp. I still need to get a heater, and am torn between a radiant natural gas model or going with an electric model. I am leaning toward the radiant heat, and am wondering if anyone else has this in their shop and how do they like it?

Thanks,

Chris

http://www.heatershop.com/garage_heater_mh25ng.html

[Marcus Ward]

Check the price of nat gas in your area before deciding on a gas heater. I have an older natural gas radiant heater in my shop space and with the price of gas lately I can't afford to run it. Electric would be cheaper.

[Dan Racette]

There are many options. If you are heating a big area, electrical was too expensive for me for a couple of options. After wiring for all the tools and such, I would have lost too much for the heater. would have had to run new lines, or deal with all the lights flickering every time the heater kicked in. Not good for running tools.

Looked into the following.

pellet stove
outdoor furnace
waste oil heater
corn furnace
LP
electric

Besides LP and electric. the other stoves were either too expensive, or I couldn't handle or get a good supply of raw materials. Installation was $$ and I had to get a new LP tank and that was $$.

Went with a 'hot dawg'. but my shop is 30 x 30.

Just be careful with electric. make sure your wiring can take it.

[Gary Curtis]

My entire home is heated with radiant panels on the wall. These work with circulating hot water from a boiler fired with natural gas. This is the second home I've had with this set up. I installed everything (except the boiler) myself.

Heat is heat. That is all that can be said about the matter. Cost is determined by how many btu's you pump into a given space, no matter how you do it. Energy sources differ by cost.

There is one big difference in how heat feels. Radiant heat more or less "caresses your cheeks". And it makes everything warm to the touch, especially 400 lb table saws. It travels around corners, so there are no cold spots. With forced air heating, the typical drawback is "hot head, cold feet."
That is because warm air rises. With radiant, you aren't heating the air.

Because it is a small space, I chose to heat my garage shop with a 220v portable electric heater. It is a cheap solution, and a bit more safe. Local Electric rates are one-half those of a big city. That's another reason.

If you are in bottled-up garage, with lots of sawdust around, you need to worry about air and fire danger above all. Now, I've seen those round tube heaters that are suspended from the ceiling, and which vent to the outside. That seems like a great nat. gas or propane solution. They also come in electric models. And they are relatively cheap. Do a google search for 'radiant shop heat'.

Gary Curtis :)

[Dan Racette]

Oh gosh, I am really agreeing with that "caresses your cheeks" line!!! Plus warm tools, yeah, that's why I am regretful, not to have that!!! I took classes in a radiant heat shop and you really hit the nail on the head there! comfort plus!

d

[Frank Hagan]

Hello,

I am looking for some advice on heating my garage shop. I just had the garage walls and ceiling insulated with a "blown in" insulation. Just the insulation has made a difference in increasing the shop temp. I still need to get a heater, and am torn between a radiant natural gas model or going with an electric model. I am leaning toward the radiant heat, and am wondering if anyone else has this in their shop and how do they like it?

Thanks,

Chris

http://www.heatershop.com/garage_heater_mh25ng.html

Sorry for the long response on this ... occupational hazard, I guess.

I checked the link, and those are neat heaters! They are very similar to the kind of heaters in our warehouse at work. I notice that for a garage installation, you don't need to provide any make-up air. I assume that means that the normal "loose construction" of a garage door and other areas of air infiltration provide enough ventilation and combustion air. If you have sealed off the garage door and other areas where air gets into the garage, you might check with them about fresh air requirements. If you haven't sealed it off, it is probably cheaper to install that kind of heater than an equivalent-sized electric heater.

25,000 BTU/hr is a lot of heat; the conversion factor to watts is .29, so that's equal to about 7,250 watts or just over 7KW, if I'm remembering my conversion factors correctly. That will help you compare the costs of electric heaters to this one. I think a 115V, 20 amp circuit is limited to about 2000 watts (AMPS x VOLTS = WATTS, but you have to size the branch circuit a bit larger than the load; usually people use 90% of anticipated load). Check with an electrician, but I think to install a comparable electric heater providing 7250 watts of heat you would need a 40 amp 230v circuit. If you have a 1/2" natural gas line available within about 50', the installation of the gas heater is pretty easy and might be cheaper than installing the electric circuit.

To compare energy costs, look at your electric bill and your gas bill. For the sake of argument, lets say you will need 25,000 BTU/hr to heat the space, or 7,250 watts, every hour.

For electricity, that's 7.3 Kilowatt hours x the rate on your electric bill if its in KWH like mine is. At .08 per KWH, that heater will cost .59 per hour to run.

For natural gas, there are two ways I know the utilities bill. One is by cubic foot, the other by therm. Natural gas supplies vary a bit in btu content, but generally there are 100,000 btu per therm, and 1,000 btu per cubic foot. I pay about .87 per therm in Southern California, so the math is .87 * .25 = .22 to run the heater for an hour.

The only concern I have is that they say no electricity is required; that might mean its a standing pilot unit. You might check with them to see; if you spray oil-based varnish or paint in that space, the normal precaution of making sure the heaters are off may not protect you from a fire or explosion. They may have a piezo ignition system that you start manually.

[Barry O'Mahony]

Those cheap radiant gas heater are always characterized as "garage heaters" because they exhaust right into the garage airspace, and the air supply is the garage itself. They put CO and water vapor into the air; if you seal up your garage well they could be a problem.

the next step up are those "Hot Dawg" type heaters that power-vent to the outside, but still draw their combustion air supply from the garage itself. if the garage is well-sealed you have to be careful that the venting is working OK, especially if you do something like have a DC in a shed outside, and the DC is already sucking out air. More expensive gas heaters draw in their air supply from the outside.

Plug-connected 120V electric heaters are limited to 1500W, no matter what their design. Direct-wired ones are limited to using 80% of the branch circuit they are on; e.g., I have two of these 5000W heaters, each on their own 240V 30A cricuit: http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&productId=595&R=595

[Jim DeLaney]

Hello,

...am wondering if anyone else has this in their shop and how do they like it?

Chris

http://www.heatershop.com/garage_heater_mh25ng.html


I have a heater very similar to that one (30K btu) in my 26 X 32 shop. 10 foot ceiling, fully insulated. This is the first year for heating with it, and it looks like it'll be costing me about $45.00 per month to keep the shop at 65° from 8:00 am til 8:00 pm, and 50° overnight. (Automatic setback thermostat) My current, contracted, gas price is $12.80 per mcf, by the way.

I like the heater. It does a very good job of keeping the temp steady, even when it was 7° outside a couple weeks ago.

Last winter, I used two kerosene heaters, and only used them when I was actually in the shop - I'd start them up about an hour or so before I wanted to use the shop, and turn them off when I left. It averaged about $2.50 per day for the kerosene at last year's price of about $1.99/gal. This year, kerosene is running between $2.59 and $2.99 per gallon, so the cost would be more like $3.50 per day, so the gas is actually much cheaper.

[Ron Jones near Indy]

Chris,
I have one that appears to be just like that one shown in your link. It is in a 24 x 24 shop that is well insulated and sealed. Some winter weather in Indiana features low humidity and temps below zero. I have had my heater for 4 or 5 years and have had no problems. I go into the shop, bump up the thermostat and putter under the heater or go back into the house for 30 minutes. That's about all the time it takes to get comfortable temps in the shop. When I leave the shop for the day, I turn it back to about 40 degrees.

Since I don't spray lacquer and similiar finishes I have not had a problem with the open flame and pilot. Yea, I like it--I would buy it again. The Hot Dawg heaters are nice but were at least twice the price when I got mine.

[Peter Pedisich]

Chris,

I'm not sure what gas costs here but my monthly electric rates with LIPA and central a/c could buy me a GMC 2500HD crew cab w/leather and satellite radio.

I would stay away from heating with electric on Long Island.

Pete

[Chris Damato]

Thanks for the advice.

Pete...it is true, we run our central AC June - Sept and the electric from LIPA is far more brutally priced than the natural gas rates from keyspan, although alot closer this year than previous years.

I really am leaning towards the natural gas radiant, but my main concern now is fumes. I used to use a portable propane and the the fumes were horrific.

[Ken Fitzgerald]

Chris....I don't know what type of natural gas heater you're considering. I just installed a Lennox 75,000 btu natural gas heater in my shop last month. It's set to keep the shop at 63 degrees and we've had temps as low as 15 degrees recently. The furnace uses inside air for combustion and does have a forced air exhaust. I've had no fumes in my shop excluding the initial ones incurred while burning the oil off the heat tubes. Good luck with your decision!

[Ron Jones near Indy]

Chris,
I have not had a problem with fumes since the initial burning. Which ever you pick--there is nothing like a warm shop.

[Gary Curtis]

Here's a link I was searching for when the thread started:
http://www.easyradiantworks.com/ezdoz.htm

The details of this product really impressed me. Particularly the ventilation. Two dangers exist in unvented heaters. Pouring dangerous exhaust products (carbon monoxide) into a small space. Consuming breathable oxygen to support the flame. There's actually a third-- danger of fumes from paints and finishes coming in contact with the flame, resulting in an explosion.

I have radiant heat in my current home. Garage versions are available as gas-fired (propane or natural) or electric. My new home is done in 2 weeks and I went with electric for the house and shop because the rates (6.3 cents/kwh) is 1/2 the rate in Los Angeles. There is no natural gas in the region, and propane is about 60 percent higher. And climbing.

Gary Curtis

[Frank Hagan]

Thanks for the advice.

Pete...it is true, we run our central AC June - Sept and the electric from LIPA is far more brutally priced than the natural gas rates from keyspan, although alot closer this year than previous years.

I really am leaning towards the natural gas radiant, but my main concern now is fumes. I used to use a portable propane and the the fumes were horrific.

There's one good thing about those smells ... they at least let you know you're breathing bad stuff! The catalytic natural gas heaters really don't produce any fumes you can smell, but do add carbon monoxide gas into the room instead of up and out the flue. So you are wise to be careful about it.

If your garage is not sealed up like Ron Jones' shop, you should be OK. (Ron, you scare the heck out of me! You aren't getting headaches or flue symptoms are you?)

One way to check is to go into the shop after everything has been off and the air is still, light a match and blow it out and watch the smoke. Or, if you smoke, take a drag and let the smoke out without dispersing it by blowing it out. Watch the smoke, and if it wafts toward the garage door, and out the top or bottom where there's a crack, you may have enough ventilation to operate the ventless heater safely.

You could also buy a CO detector and install it in the shop. I've had nuisance trips with sawdust with them, but the newer ones are said to be better, and have a readout on them, so you can see the PPM rating. They aren't dead-on accurate, but if you have it on to establish a baseline before you switch on the heater, then heat the space, you'll get an idea of the exposure. The most stringent standards now in place say not to exceed 9 PPM for an 8 hour period for children; the state of Michigan has a standard that is 35 or 40 PPM, and the old OSHA standard for workplaces was 50 PPM for 8 hours (some standards are 35 PPM for the 8 hours). You don't want to be much above that 50 PPM for long exposure.

[Ron Jones near Indy]

Thanks for your concern Frank but I'm sure I'm getting along ok. No headaches or flu like symptoms. Seems like I'm never in there for more than 2 consecutive hours. Even then I hear the neighbor's dog bark and I stick my head out the door to see if I have a visitor. Like everyone else, I hate suprises when I'm using a machine. My CO monitor has never indicated a problem.

[Frank Hagan]

Thanks for your concern Frank but I'm sure I'm getting along ok. No headaches or flu like symptoms. Seems like I'm never in there for more than 2 consecutive hours. Even then I hear the neighbor's dog bark and I stick my head out the door to see if I have a visitor. Like everyone else, I hate suprises when I'm using a machine. My CO monitor has never indicated a problem.

I think I called it an "occupational hazard" before ... I talk to the survivors and the families of the not-so-lucky once or twice a year, so I'm a little bit of a nut on this issue. 200+ deaths a year due to CO poisoning is too much for me.