OWB fed Garage Heater - Forced Air or Radiant?

[colson04]

So, for the folks with OWB, how are you heating your garages or shops? I have a 20'x24' attached and insulated garage that I want to heat, but I'm not sure which way to go. My dad suggested an old furnace with a radiator plumbed into my OWB which would be easy enough to do. Another route I thought about was getting a couple large, cast iron radiators from an old house and plumbing those in on their own zone. Garage already has a concrete floor so radiant in floor heating is out.


What are you guys doing? Is the old furnace w/radiator the best route? Any other suggestions?

 

[Guswhit]

I have a buddy who is a heating guy and he salvaged a blower unit off an old furnace. I bought a small cheap exchanger off fleabay and he then fabbed up a small shroud that we pop riveted the two together. I used a 110 thermostat to activate the blower and it worked great. I had to add some deflectors to the front later because I mounted it up so high in the garage to get the airflow going down more. I needed the downward flow more to get my snow plow truck thawed out overnight. Wife bitched up a storm about me spending the money on the owb until that first snow storm she drove home in. The next morning when her car was thawed out and warm to get into, I turned into the biggest hero ever!

 

[upsnake]

I did the same thing as Guswhits setup, small blower motor 100 dollar hx from ebay, bent some stainless to join them together and a 110 thermostat.

I don't keep the garage heated all the time, so it is nice when you want to quickly warm it up.
If you were heating it all the time radiant might be nicer b/c no electricity usage in the blower.

 

[legg28]

Here's what i got it is a central boiler hanging heater and works good . Or like Guswhit said you could make one like it out of old furnace parts. My garage is 24 x24 and insulated pretty good and this thing will heat it up quick ! Keeps the temp at 45 or 50 without the fan even running .

 

[upsnake]

Here is my set up.
I ran the 110 thermostat after the pics were taken. I got sick of plugging it in and unplugging it.

 

[colson04]

Well, I think that pretty much settles it. I'll just go find an extra blower for a furnace and get me a hx somewhere and hang it up near the ceiling out of the way. Maybe that will be tomorrow's project.

 

[wndwlkr]

I use this for my shop, as others have said, you could build one pretty easy. Mine is built by Trane & It's pretty old but it keeps my shop whatever temp i set my thermostat. good luck whatever you decide.

 

[colson04]

wow... wndwlkr's system looks quite a bit more complex than what I have going on over here...

 

[legg28]

wow... wndwlkr's system looks quite a bit more complex than what I have going on over here...

You got that right !!

 

[Johnny Yooper]

I use an OWB to heat the house and hot water and a 24x36 shop with 10' ceiling; I made a hx about 24" square from left over radiator pieces when we built the house; was going to put in floor in when building the shop, but time and money were being directed to the house (did install in floor heat in the basement, and damn glad I did that). Mounted the unit on the wall about a foot below the ceiling and angling downwards. I bought an elcheapo 20" box fan and mounted that behind the hx, don't look as pretty as those in the pics, but at -15F, I can get the shop to 65F. I installed unions and shut off valves on the supply and return lines to make it real easy to remove/repair/reinstall in case something were to go sour with the hx.

 

[ash man]

I got 2 old cast iron radiators free from a buddy of mine and that's what I use to heat my 2 1/2 car garage. I have a way to bypass it and adjust the flow to the radiators depending on how cold it iz outside. I would have gone the forced air route if the cast ones we're not free.

 

[Butch(OH)]

I built a wall "unit" which is a rectangular box built from plywood that is two feet wide and one foot out from the wall. Starting at the bottom there is a two foot high opening that a box fan just fits inside of and a standard furnace filter is in front of. Above it at head height is another opening with a car radiator fitted. In operation the fan draws in air from the floor and it goes up the box and out past the radiator. Temp is controlled with a line voltage thermostat. Less than $100 in it and been heating the shop for now 7 years. If pinched for room the same thing could be built between 16" studs with the correct fan and radiator. If anyone would like pics I will take some, its not a work of art but very functional.

 

[colson04]

I built a wall "unit" which is a rectangular box built from plywood that is two feet wide and one foot out from the wall. Starting at the bottom there is a two foot high opening that a box fan just fits inside of and a standard furnace filter is in front of. Above it at head height is another opening with a car radiator fitted. In operation the fan draws in air from the floor and it goes up the box and out past the radiator. Temp is controlled with a line voltage thermostat. Less than $100 in it and been heating the shop for now 7 years. If pinched for room the same thing could be built between 16" studs with the correct fan and radiator. If anyone would like pics I will take some, its not a work of art but very functional.

I would like to see that Butch, if you have time to post some pics. I like the idea of building in a cold air return, plus the cost seems very reasonable.

 

[blackdogon57]

Forced air gives an instant blast 0f heat. I often use my garage heater when I am working outside and want to warm up or fix stuff without changing out of my dirty work cloths. Very handy with the recent cold weather. The bigger the rad the better. My blower doesn't even kick on that much. The rad and the pipes keep things pretty warm. Insulated doors are a must.

 

[upsnake]

Blackdog, what kind of fan do you have behind it? is it something you built yourself? Also is that just think sheetmetal to direct the air?

 

[04titanse]

How do you guys avoid having pipes freeze when your not heating the shop? Since I don't plan on keeping my shop heated all the time I would be worried about pipes freezing. I am thinking I may just throw a wood stove in there.

 

[colson04]

The water is always circulating in these systems, that's why they don't freeze.

I'm planning on doing a similar system w/radiator and fan, but I'll probably insulate my lines to reduce radiant heat loss.

 

[upsnake]

Yup water is always moving, (and it is hot ).
I was going to insulate them, but I figured a little radiant heat loss in the garage would warm it up a little with out having to run the fan.
(The heater is just in my attached 2 car garage, so a little warmer in there, is only going help the house, and getting into a warmer car in the morning is not a bad thing either).

 

[danl]

My Hardy doesn't circulate water all the time, so I have a thermostat that goes down to I think 40 so I set as low as it will go. I don't want it to ever get below freezing. Have expensive cattle meds, paint etc that doesn't need frozen.

 

[04titanse]

Ok that makes sense, thanks.