Garage heating advice?

[redairrdstr]

Hello,

I am laying out the plans for my new garage this spring with a contractor. All along I have been thinking I would try to put in a radiant floor heat system, but the more I look and think about it, I am not sure if this would be the best set-up for me. My main goal is efficient heating.

Heat fuel sources: Propane or Electric

Garage details:
36' by 42'
10 foot walls, 2x6 stick framed and insulated.

Garage use:
Hobby workshop for old cars, motorcycles, and maintenance, and various other things I find interesting.

I am in Central Illinois so are temps widely vary. I would like to keep the garage heated throughout winter, maintaining 50 to 60 degrees and possibly a little warmer when working.

Realistically, I will probably work in the garage a couple of days per week in the winter since it is a hoppy shop...

Until we built our current house, I have always had the luxury of well priced Natural gas, and our house is on a geothermal system. The idea of heating the garage with LP/Electric worries me cost wise.

I started poking around at different heat sources and am now completely unsure of what to do.

Some system options I've come across:
Radiant with electric or LP microboiler
Modine LP Hot Dawg
Mini-split which offer AC also


So what do you guys think the best option for my application would be?? Also, open to other system suggestions, these are just a few I came across.

Any help would be appreciated

 

[Bondo]

Hello,

I am laying out the plans for my new garage this spring with a contractor. All along I have been thinking I would try to put in a radiant floor heat system, but the more I look and think about it, I am not sure if this would be the best set-up for me. My main goal is efficient heating.

Heat fuel sources: Propane or Electric

Garage details:
36' by 42'
10 foot walls, 2x6 stick framed and insulated.

Garage use:
Hobby workshop for old cars, motorcycles, and maintenance, and various other things I find interesting.

I am in Central Illinois so are temps widely vary. I would like to keep the garage heated throughout winter, maintaining 50 to 60 degrees and possibly a little warmer when working.

Realistically, I will probably work in the garage a couple of days per week in the winter since it is a hoppy shop...

Until we built our current house, I have always had the luxury of well priced Natural gas, and our house is on a geothermal system. The idea of heating the garage with LP/Electric worries me cost wise.

I started poking around at different heat sources and am now completely unsure of what to do.

Some system options I've come across:
Radiant with electric or LP microboiler
Modine LP Hot Dawg
Mini-split which offer AC also


So what do you guys think the best option for my application would be?? Also, open to other system suggestions, these are just a few I came across.

Any help would be appreciated

Ayuh,.... If ya don't put radiant tubin' in the floor, with insulation,...

You'll be kickin' yer own ****, til the day ya die,....

How 'bout runnin' the radiant, Off yer house's Geothermal,..??

Most geothermal pumps put out excess hot water don't they,..??

 

[finn]

Radiant works well if you want to maintain a steady temperature, but doesn't respond quickly if you want to increase the temperature on demand. The thermal mass makes it impractical for that.

There is probably no reason to increase the temperature above 60 degrees to work in the shop if you elect to maintain the shop at 60 though, as all the contents, including tools will be at a comfortable 60 degrees, and the floor will be significantly warmer.

I generally keep my shop at 49 degrees, and the floor is in the low 60s. This week the outside temp is in the teens during the day and low single digits to a little below zero at night. I dropped the thermostat as low as it will go to save on the fuel bill. The thermometer on the wall now says 43.6 degrees and the floor is 55 degrees. Perhaps a little cool to spend the day working in the shop, but not undoable.

If you are serious about heating the shop full time, radiant is the way to go. Some sort of air heater is better for intermittent heating.

 

[sixty4]

When I put up my 40x30 garage I did the radiant heat (I had planned on a peerless purefire and fan coil unit). However as time went by, I thought about the amount of time I really was going to spend during the week out there (its a detached). I am on propane as well. I ended up putting a hot air furnace and ac system in (Rudd with no regrets). I drain the water from the building when the sprinklers are shut down anyway so no worries about a pipe bursting or freezing. Yes I am aware they make anti-freeze for hw systems. For me it was a better choice.

 

[PAToyota]

At least put the tubing in the floor - it’s fairly cheap and then you can make up your mind later. If you don’t do it, then you don’t have the option.

That you want to keep it heated continuously lends itself well to radiant. Radiant is a poor choice if you only want to work for a few afternoons a month - you’d pretty much have to turn it on the day before to let it warm up enough to work. For infrequent use, something like a suspended radiant heater would be much better.

The other thing is that with radiant you can keep the overall temperature lower. Like Finn says, the air temperature can be cooler than the floor and you’ll still feel warm. If you keep it at 50℉ I doubt you’ll feel the need to “warm it up” when you’re out there. I’d say you could probably even drop it lower than that - particularly when you’re not out there.

 

[Adk Mike]

I use a Hot Dawg. Works real good. My shop also a hobby shop. I leave the heat off during the week. I turn it on for the weekends. If drying paint it may be on for ten days or so. Most shops like yours a couple hundred gallons of propane a year. Set a 500 Gallon tank and fill it only in the summer.

 

[jimindm]

A friend built his garage a few years ago. He put all of the runs in the slab for in floor heat. This fall he set out to hook it up and get it running for winter. He said there is now a switch in most heating units that will detect raw fuel. When it triggers it shuts the unit down, until a circuit board can be replaced.

Not sure if your boiler system would have it, but he said the hot water heater he had planned on using had one, as with most full size furnaces. Eventually he just bought a hanging furnace from Northern Tools. He did not see that it had the safety switch on it, but he figured if is was on the ceiling no gas fumes would get that high.

I have had a reznor for many years. In central Iowa we have the temperature changes all winter. This weekend it has been in the upper forties, and by the middle of the week they are predicting single digits.

I have been in many shops with different heating sources. In floor heat is ok. Like others have said it takes a long time to change the air temp. I have found it is ok if your are doing anything on the floor. It just has that cold feeling if you are working on like a workbench for a while.

Ceiling radiant heat is about the same way. Nice if you are under it, in the open. Not so much laying under, or in a vehicle.

My forced air reznor has worked great for me. Before I started working full time in the garage, I could come home after work and turn it up. By the time supper was ate it was warm enough to go work in it. It did not take long to just set the thermostat and leave it.

Remember everything else that may be contributing to your heat. I have a 24x30 with 12 four tube florescent light fixtures. They are the old style. Once the lights are on many times the furnace seldom runs. It will if the overhead is opened, or a cold car is pulled in.

This many lights also makes it very warm in the dog days of summer. I used to have all of my lights on two switches. Last year I installed a switch on every light that I could turn each fixture on or off. Now in the summer I have just a few light running, I suppose it would be like task lighting.

I would say do your best at insulating and making the garage tight. Any kind of heat will work better. We are on natural gas, and you did not mention that as an option. I guess you would have to look at the costs with the fuels that you have a available and determine what is best. I like my forced air hung unit.

 

[rburke65]

I installed the tubing but as of yet I have no boiler but most folks on this site like their radiant heat.

 

[CNGsaves]

Since OP is in Illinois, plenty cold and quite a few snow storms so far this winter.

Update GJ Profile with location.

In the short-term, +1 that hanging garage heater (propane) would be best solution until you later implement your radiant floor heat which will be ultimately your winner. Hanging heater would give you quick warm-up and COULD handle fumes from painting if you went with Separate Combustion heater like Reznor UDAS . . . . the "S" stands for separate combustion where outside air is brought in with separate flue, in addition to exhaust flue.

Spend the money/effort at SEALING up garage . . . and . . INSULATING. No use trying to heat the outside !!

Also, your decoder ring to decipher posts by Bondo . . . ie the Ayuh (means Yes). . . is look up Maine speak, or just add all the letters he left out of post and re-read it a second time !!

 

[sberry]

I like he is going 36 wide, every bit helps in a building this size, 40 is better but,,, I am all for low level continuous heat, wish I had it in the floor. A well insulated building this size is easy to heat above freezing and if I was going to be in it much at all would keep it 40 or better if I was there a lot. I don't want my house to freeze and wouldn't want my workshop to either. Its in the door its safe in cold weather.
I have a floor drain, de ice and dry and warm park in extremely cold weather especially if we are early traveling in 0 weather.
36 and 42, you wont regret the extra 2 from a cookie cutter 30x40 either. Most of the expense and at this size a little heat is in the 4 corners and roof peak. You would never regret to going 40x44 either especially if you tend to be busy. The sq foot never gets any cheaper than it does at this stage

 

[sberry]

I installed the tubing but as of yet I have no boiler but oust folks on this site like their radiant heat.

You could go over to the heating forum but you could probably use a common gas water heater for a modest insulated garage.

 

[chruler]

There is absolutely nothing like radiant heat in the floor! It's the bomb! But only if you use it often enough to make it worthwhile.

 

[theoldwizard1]

The idea of heating the garage with LP/Electric worries me cost wise.

Some system options I've come across:
Radiant with electric or LP microboiler
Modine LP Hot Dawg
Mini-split which offer AC also

With those 2 fuel choice the solution is simple: mini-split heat pump. Not the cheapest to install, but it will pay for it sell and you get A/C !

For a garage that big (36'x42') you are going to need 2 air handlers and probably a couple of ceiling fans. Most mini-split heat pumps handle 3 or 4 air handlers.

Do your research. You MUST purchase a min-split heat pump that has GOOD cold weather capabilities ! Some will maintain 100% efficiency down to 0F.

View media item 43975
Proper underfloor insulation and vapor barrier are still important even if you do not do radiant floor heat.


Radiant floor heat IS still possible with a mini-split. One zone (output) off the compressor would run to a hot water tank/refrigerant-to-water heat exchanger and then on to the manifold for the floor. I would seriously consider this in any area that you will be working (as opposed to storage areas) in addition to the air handlers.

 

[redairrdstr]

Thanks for all the replies so far.

Natural gas is not available to me.

I am not really familiar with the hanging furnaces (Reznor/Hot dawg), so bear with me...

Are they thermostatically controlled?

Could you run them to maintain a steady temperature through winter?

Also, is my understanding that gas fumes/paint fumes are heavier than air, so it would be safe to run these furnaces in a shop with such things going on?

thanks again

 

[theoldwizard1]

I am not really familiar with the hanging furnaces (Reznor/Hot dawg), so bear with me...

Are they thermostatically controlled?

Yes

Don't pass over the mini-split without further investigation ! It will save you money in the long run !!

There is absolutely nothing like radiant heat in the floor! It's the bomb! But only if you use it often enough to make it worthwhile.

I agree 100%. Although the combination of a heat pump and radiant heated floors is not common in the US, it is common in other parts of the world.

 

[danski0224]

Thanks for all the replies so far.

Natural gas is not available to me.

I am not really familiar with the hanging furnaces (Reznor/Hot dawg), so bear with me...

Are they thermostatically controlled?

Could you run them to maintain a steady temperature through winter?

Also, is my understanding that gas fumes/paint fumes are heavier than air, so it would be safe to run these furnaces in a shop with such things going on?

thanks again

Thermostat- yes

Run all winter- yes

Gas/paint- I suppose that depends on local codes. Water heaters are allowed as long as the burner is 18" above the floor in my area, for example. I would suggest, at a minimum, getting a sealed combustion unit heater with an outdoor fresh air intake. If you plan on doing lots of painting/finishing, then that is another can of worms.

 

[redairrdstr]

Yes

Don't pass over the mini-split without further investigation ! It will save you money in the long run !!

Im definitely not passing this over, I was just typing my other response when you posted up. I'm glad someone chimed in on them, cause until recently I was completely ignorant of them. Still, don't know much, but I am researching each idea as they come and will hopefully come up with the best way to go from there...

 

[roscoe2000]

If is is not a dollar issue (installation cost), a radiate floor heat is the way to go. As your floor slab acts as a heat sink, then that heat radiates upwards naturally. Water (your transfer medium) is more efficient to heat than air as in forced air. You will be able to maintain a lower set point cause the lowest point in your area is providing the heat. Unlike forced air, once the leaves the duct work it will try to rise to the ceiling...leaving the a blanket of cold air at floor level. Installation cost is the killer.....but over the long run it would be cheaper to run.

 

[tipsy]

My two cents. I live in Morton, IL. I am a handyman and I have a customer who has a fairly new home, three car garage with radiant floor heat. Keeps it comfortable in our winters. Garage is attached to house and radiant system is supplied by a separate water heater that they fire up in the fall.

 

[redairrdstr]

Thermostat- yes

Run all winter- yes

Gas/paint- I suppose that depends on local codes. Water heaters are allowed as long as the burner is 18" above the floor in my area, for example. I would suggest, at a minimum, getting a sealed combustion unit heater with an outdoor fresh air intake. If you plan on doing lots of painting/finishing, then that is another can of worms.

Not a ton of full on car painting, but I do a lot of parts painting when working on my old cars and I have an old truck that I plan on painting myself

If is is not a dollar issue (installation cost), a radiate floor heat is the way to go. As your floor slab acts as a heat sink, then that heat radiates upwards naturally. Water (your transfer medium) is more efficient to heat than air as in forced air. You will be able to maintain a lower set point cause the lowest point in your area is providing the heat. Unlike forced air, once the leaves the duct work it will try to rise to the ceiling...leaving the a blanket of cold air at floor level. Installation cost is the killer.....but over the long run it would be cheaper to run.

I don't mind spending more money up front if it will save me in the end, I'm looking at the long haul as we plan on staying in this home indefinitely, but I don't want to spend a premium for install/equipment if it won't be anymore efficient at keeping a consistent temperature than other options.

My two cents. I live in Morton, IL. I am a handyman and I have a customer who has a fairly new home, three car garage with radiant floor heat. Keeps it comfortable in our winters. Garage is attached to house and radiant system is supplied by a separate water heater that they fire up in the fall.

Nice to see another local on here! I have heard of people doing these systems with hot water heaters, but I wouldn't think a hot water heater would be sufficient for my size shop as a heat source?

 

[finn]

Most of the hanging heaters seem to be in the ~80% efficiency range, while boilers are in the ~95% efficiency range. That helps offset the higher installed cost over time, but you are constrained to 24/7 operation, unless you move to antifreeze as a medium, which has directionally worse heat transfer characteristics than water, and is relatively expensive.

In floor heat is a pretty big commitment.

 

[danski0224]

I don't mind spending more money up front if it will save me in the end, I'm looking at the long haul as we plan on staying in this home indefinitely, but I don't want to spend a premium for install/equipment if it won't be anymore efficient at keeping a consistent temperature than other options.

You are on your own to research system costs.

That said, it will be far less expensive in the long run to use infrared radiant tube heaters vs a forced air unit-style heater, if a tube heater can be installed in your space.

There are plenty of testimonials/feedback online.

Note on heating equipment "efficiency": AFUE is a rating created with smoke and mirrors, it is in no way connected to actual combustion efficiency.

 

[redairrdstr]

You are on your own to research system costs.

That said, it will be far less expensive in the long run to use infrared radiant tube heaters vs a forced air unit-style heater, if a tube heater can be installed in your space.

There are plenty of testimonials/feedback online.

Note on heating equipment "efficiency": AFUE is a rating created with smoke and mirrors, it is in no way connected to actual combustion efficiency.

Interesting, I have not considered this, I'm assuming you are referring to the Propane tube heaters that hand from the ceiling? Can you suggest a manufacturer to check into? Do they have to run the length of the building to supply heat? I forgot to mention one end of my shop will have scissor trusses for a lift...

Man I did not think it would be this difficult to choose a heat source, just reading through the responses to my post there are several "best ways", maybe I am just overthinking it

 

[mechanic217]

My shop is 1200 square feet , 10 foot ceilings stick built in the early 80's, heat is a Rinnai propane heater ,I do not heat the whole space , some is just storage, this summer more insulation is planned and solar hot air panels to help keep the propane costs down, looking back and forward insulation gives the most bang for the buck, the actual heat source is secondary, but with a new shop definitely put the radiant tubing in.YMMV

 

[mygarageone]

Unless you have every had or worked on a radiant floor , you'll never fully appreciate them.
I have installed every kind of heating system you can install and I installed radiant floor heating for my place.
The next best thing is a radiant tube unit at the ceiling . Forced air which I also install can not and never has been even close to as comfortable system as radiant floor or radiant tube at the ceiling.
Short of the A/c with forced air , I don't know anyone who does heating systems , who wouldn't have a radiant floor system. And it's not expensive to operate .
So when it's in the idle non use mode , let's say at 45 degree's. And you know you'll be in there the next day , turn it up and you'll have what you want .
If you can , at least do the prep for the future floor heat , it's amazing how things change and what we thought we wouldn't be doing , we now do and wish we had done that thing differant yrs before.

Hid sight is worth a million bucks , forsight is worth 2 million.

 

[danski0224]

Interesting, I have not considered this, I'm assuming you are referring to the Propane tube heaters that hand from the ceiling? Can you suggest a manufacturer to check into? Do they have to run the length of the building to supply heat? I forgot to mention one end of my shop will have scissor trusses for a lift...

I'd start with google...

There is one or two outfits making the tube heaters specifically for low ceiling spaces like a garage instead of a warehouse.

For the best system, you will want the manufacturer (if they sell direct) or the distributor to design the system from your approved plans. The parts add up quick.

 

[michael.a.lilley.9]

I have a 30x40 pole barn that I put radiant floor heat in. Well, the pex anyway. I haven't had time to insulate yet but it cost me right at $1/ Sq foot. You can't add the pipe after the concrete is poured so if you got the money I'd do it now if I was you.

 

[stout]

I use a mini split heat pump in north eastern wi on my 24x24 detached garage. It is insulated pretty good and the heat pump has worked great so far. For a reference during the month of January when it was super cold here, like minus forty with the windchill, my monthly bill was $110 and I had it running most of the time. It wasn't seventy in there but you could still work.

 

[2slow]

As many have said, if you are going to heat to 60 all winter, radiant floor heat is by far the best way to go. Not sure if you are going to want to heat a hobby shop year round on propane though... If you end up wanting to change temp quickly radiant floor heat is not your friend, it is slow to respond.

My friend has radiant floor that he keeps at 40 all winter and a hanging hot air unit he turns on when he wants to work in the shop. Best of both worlds, but high initial investment.

In your case, I think you should go with the radiant floor heat since you plan on leaving it on all the time. If you change your mind it is easy to add a hanging heater later.

-Joe

 

[pcarter275]

Love my radiant!