Technical Winter shop heat

I finished a new small (1000) sq ft) shop last fall with 12.6 ceilings. New construction, well insulated and to keep it at 70 days and 50 nights on propane it cost me between 50 and 75 dollars a month thru the 7 winter months here in Nebraska. The contractor installed a Hot Dawg hanging unit and so far it's worked great. I cool it in the summer with a 25,000 btu wall air conditioner and it did the job for about 50 dollars a month set at 72. Hate the heat but hate to be cold even more

 

Gerahead, I hope you were kiddin.That's my living room.lol.Bruce.

 

Thanks guy's. This is a lot of good info.

 

Not a clue, Brother..........What does the PDF read?

It gives no guidelines on placement?

 

Propane Furnace in the attic of the garage. Just set the thermostat. I keep it at 50 and kick it up when I am working. Garage is 2x6 walls well insulated.

 

plus THREE 32 fords hold some heat.

 

The 40K btu unit would be big enough for the space, but I doubt it would provide a satisfactory heating solution.

You would have to mount it at an angle to get any coverage to speak of. Radiant heaters heat objects rather than heating air, and radiant heat transfer varies inversely as the square of the distance from the radiant source. What this means is that you'd have a real significant temperature difference from one side of the shop to the other. You'd also have a zone within a few feet of the face of the heater where it would be too hot to work comfortably if the heater is running.

Because radiant heat is line of sight, anything in the path of the heater will further reduce the heat available at the far side of the shop. To further explain "inversely as the square of the distance", lets say you hang the heater at an angle and 2 feet off the 28 ft long wall. Now measure the available heat at 7, 14, 21, and 28 feet from the heater. At 14 ft you'll have 1/4 as much heat as at 7 feet. At 21 ft you'll have 1/8 as much as at 7, and at 28 ft, which would be the far wall, you'd have 1/16 as much heat as you have at 7 ft. And, as mentioned above, any large obstruction standing between the heater and any point where you measure the available heat will reduce the available heat even more.

Don't mistake what I'm saying as coming from someone who doesn't like radiant tube heaters. My shop where I make a living is 60x150 ft and it has them. Best shop heat you can have from both a comfort and operation cost standpoint, but only if the ceiling height is adequate to allow the heaters to be hung horizontally and high enough to allow the radiation to spread. The heaters in my shop are medium intensity ones, hanging at about 16-17 ft above the floor. Because they heat objects rather than heating air, your body doesn't radiate heat to cold surrounding objects like it does with other types of heat. As a result, if you're doing any sort of normal physical work in the shop, 60* is plenty warm to work comfortably.

Since you've already got the heater, there's no big cost in trying it to see how it works for your shop. Just don't be surprised if it doesn't work out too good. Radiant tube heaters are expensive, and Roberts Gordon is one of the best brands on the market. If yours are in good operating condition, you could likely sell them for enough to buy something else new, like one of the Reznor heaters mentioned up above, or a similar product, that would work a lot better for your application

If you go to the home page of the Roberts Gordon website, and click on products, you can then go to any model of heater they make and download the installation instructions that will give all the necessary clearances to combustibles, minimum mounting heights, etc..

 

Here in the Arctic of Minnesota I did use a 100k BTU hanging furnace in my 4 car shop. Last week I ripped it out and replaced it with a new 80k house furnace that is 96% efficient. The BEST thing I ever did. $1500 furnace, got the good guy deal for $900... and then got a $400 rebate from the gas company !

 

My Hot Dawg heater is worth every penny!!Last year I never heard a word about the gas bill.As far as a gas heater, these are the nuts

 

Thanks so much for the reply. I was kinda thinking that they would not work all that well due to the low ceiling height. Bugger! Now I presume gas is the way to go and not electric, correct? Maybe I'll try the smaller of the two units and see how bad it is. Another question, I have a small 220v box size construction heater that are fairly common. However it only heats up a small area in front of it. Can I change the plug so it will connect to my 220 welding extension cord so I can have it where I need it when I need it?

 

Yes,, change the plug on heater, welder, etc . Get outlets and plugs all in sync.

 

my garage is 20x25 with 10' ceiling. insulated walls, door and ceiling. luckily, i had a 30-amp line for the compressor, so i used that for a 230 volt ceiling mount heater. keeps it in the 70s on single-digit days. if you go that route, get a heater with front-mounted controls. by the way, i ran a 12 ga. wire to run the compressor on 20 amps!

 

I use this type of heater.
It works like a reversed ac.
Im usally start it in october-november and
stop it mars-april depending on weather.

 

So the style of plug has no relationship to othe amperage? If not then why in hell do they have different plugs?

 

How many watts is you electric heater and how is the electric bill?

 

To piss you off,,,you can buy a combination plug. You can move the plugs on them to suit the receptacle.
http://www.ebay.com/itm/50-Amp-Male...hash=item33ae787f04:m:m3CdGI46Gb2leUsocQu0v-Q

 

I hope you don't think I was questioning you. I question the powers that be most days. One plug for my mig, another for my arc welder, another for my little heater, another for stoves,..... Why are they not all the same?

 

I have an outdoor wood burner by Central Boiler. I heat 2 homes & my shop all about 1200 square feet each. Works great.

 

I have a hangin heater that runs on natural gas. It was new when installed. My garage is 24x30,this is where I make my livin. Every month, the power company sends me reports on my consumption of gas and electric for the house and shop. It runs from 92 to 98% compared to similar homes. With 1% being the most efficient. Even in the summer time too.

 

When I added a 36x36 addition to my 2 car garage I spoiled myself and installed (8) 150' loops within the slab, powered by an on demand NG water heater. Radiant heat is where it's at, even when it hit -24* last winter the thermostat was set at 65* and that's where it stayed at.

 

Fortunateson, I believe they put different plugs on the 220 volt appliances so you don't plug your clothes dryer or your welder into the stove outlet etc. Each appliance draws different current than the other so if you put an appliance with a large current draw into the receptacle of a lower current circuit, bad things could happen.
I use one of those portable construction box heaters (4800 watts) in my shop (24' x 24') and it just keeps up in cold weather around freezing. After half an hour I feel comfortable.. I changed the plug on it to fit my welder receptacle and it works just fine. These days I don't go out to the shop so much when it is cold.

 

I know it;s been mentioned earlier in this post but let me remind all you guys using open flame heaters be it propane, kerosene, wood or whatever that's not directly vented outdoors that you are risking your lives big time. Whenever an open flame occurs it is using up the available oxygen in the air and replacing it with deadly colorless, odorless, carbon monoxide gas that kills people every day without their knowing it's happening. take it from my 29 years experience as a firefighter that it's serious stuff. Be warm but be safe. My own 30x30 garage is heated using a warm air oil fired furnace and duct work to distribute to heat to all4 corners. I am Ralphie

 

Why did you switch from water boiler to forced air? I've built barrel stoves in the past but feel uneasy leaving the shop while they are burning. I thought about building an outside forced air unit but then there is still the risk of burn through and blowing sparks inside. At least that's the line an insurance company would take and possibly a fire Inspector. Right now I'm thinking of building a two barrel long stove outdoors and circulating propolyne glycol mix through a motorhome radiator I have that would be mounted on the inside with a 120v box fan behind it.

 

a farmer friend has an outdoor furnace to heat his house, he is in the process of routing a hot water line to his shop and mounting a gutted whole house air cond. unit to the ceiling. he left the cooling radiator intact, plumbed the water to it and mounted a fan.

 

I went to see my buddy a couple years ago. An 80 year old transplant from Louisiana after the big Hurricane. He was using Kerosene heaters. For some odd reason, he was shivering. I asked another guy (Jerry) who happened to stop by too. Have you ever seen him cold. So we asked him if he was okay. Long story short, We called the ambulance when he couldn`t walk. Two hours in an oxegon bubble at the local hospital and then was sent to the city for 3 days in a oxegon bubble. I told Jerry to go down to his place and throw them dang Kerosene heaters in the garbage. He told us later that he had trouble stating one of them. The Doc said that most people would of died because his oxegon level was so low.

 

When I built my 27 x 40 shop a few years ago I ran a natural gas line and installed a mobile home furnace, it worked very well, then started having issues and got tired of having to work on the furnace all the time. So I ripped it out and installed a pellet stove in it's place. Works very well I use a pellet stove insert in my house so the pellets are already here and it can run all day keep the shop at 58- 60 for $5.00 a day. Best most economical heat I have used in a garage/shop. My old shop I had a heat pump it worked well but not nearly as economical as the pellet stove. The flame is inside a sealed door. I get no fire smell it is quiet, you get the site of the fire behind the glass it's easy to fill easy to clean. Easy to install I vented it through the old furnace flue pipe upgraded to pellet stove specs. You can vent a pellet stove right through a side wall if you wish very easy to maintain. Joe

 

I heated my 1,200 sq. ft. shop with wood for the first 5 years of having it. I had heated my house with wood in the past and liked it. But since I wasn't living in the shop, I didn't want to leave a fire going overnight. That meant that on some mornings when I got to the shop, it was 32 degrees inside. I would build a fire and stand over the stove for an hour or so trying to stay warm while the shop warmed up. I was wasting a lot of time that way. I asked our heat/air guy whether he had a used gas furnace he could sell me. He did, and he charged me $125 for a reconditioned furnace and installed it for $200. I have a small excavator, so I dug the trench and installed a gas line to the building. Presto! Warm shop! I set the thermostat at 45 degrees on cold nights, and it's 45 or more when I go there. (45 is a lot different from 32!) I turn the thermostat up to 63 degrees and can go right to work. The shop is warm in about half an hour. It's the best $325 I've spent equipping my shop. If running a natural gas line is totally out of the question, you could always get a big propane tank and have it filled once or twice a year.

 

Love your heater John great idea and If your neighbors ever give you any crap you can throw them in there too.

 

Not bad really. The shop is over insulated so retains heat really well. I think I paid $1100 each for them. Takes a little time before they really start to work efficiently, once the shop is at optimum temp, the cycle times are spread out further= less gas usage.

 

My original first design was a lot like what you are thinking. It took several revisions to get a system that worked well. There is more to it than you would first think. I had to experiment to find the correct boiler, the flow rate of the fluid, the size of the heat exchanger, and the amount of air movement for the heat exchanger. All of these variables effect the efficiency of the system. I like my shop to be 70 degrees when it is below zero outside.

If your air plenum is pressurized there should be less chance that you could pull a spark into the plenum. I am using a very heavy walled firebox and I plan to inspect it frequently.

I think the forced air system will be easier to operate.

John