Shop Heat

[Mark Blatter]

I started my shop a little over two years ago. I had it mostly completed by June or so of last year, but was busy and just didn't the heating system completed. All last winter I used a space heater, burning through I don't know how many tanks of propane. All the time, the on-demand water heater and the manifold was installed on the wall. All I needed to do was put up the thermostats and control box, then fill the system with water. I swore I would get it done this past summer.

Suddenly I realized it was October and getting colder and my shop was getting a bit cool during the night so first thing in the morning I was wearing a jacket. I kicked myself in the behind and a week ago took the time to get things put up. It took all of about 90 minutes to install the thermostats. Then last Friday I started filling the system with water. I have a single zone, with four loops of tubing, and it took me about 3 hours to get it all filled using just at 14 gallons of water. I used distilled though not sure I needed to. I did not put in any antifreeze as I don't intend on letting the place freeze. I may change that at some point, but for now it is just clean H2O.

I fired up the water heater on Saturday afternoon and thought it would take 4-5 days to get the floor warmed up. I went out on Sunday morning to check it and wonderfully the place was a nice 68 degrees or so. I had to turn down the thermostat because it was actually too warm. I fought the cold all last winter, making trips to the propane depot half a dozen times with 4 - 6 bottles, endured the smell of the burned propane, all because I didn't take the 5 hours to get the system finished. I ask myself at times, How dumb are you to not just get it done?

I can now say that it is incredible to have radiant heating up and running. Had to have the overhead door open for about 90 minutes loading some cabinets into a trailer and when I closed the door, the shop still felt nice and warm.

If anyone ever is considering radiant heat, don't think, just do it.

[Bruce Page]

I would love to have radiant heating. I used kerosene heat for years in my garage shop before installing an overhead hotdog type heater. I wish I would have installed it years earlier.

[Ken Fitzgerald]

Mark, I am envious! I wanted what you have but the city code required I have a water source in the building or a special protection circuit in case of a leak which the only quote I got was beyond my means. Thus I have a Lennox hanging space heater which works well but I'm sure not as efficient or economical as the radiant floor heat!

[Lisa Starr]

For Ken and others considering radiant floor heat without a source of makeup water. You only have to install a low water cutoff to meet code in most jurisdictions. My particular boiler recommends one even when connected to a water supply. They cost from $200 to $600 depending on the design. The idea is that if the system is low on water, the cutoff prevents the system from firing.

[Frank Pratt]

Radiant heat is nice, but not optimal for my situation where I keep the shop (garage) at about 5 degrees when not using it. When I work out there, I want to heat it up in a hurry. My shop is heated with a 60,000 BTU residential forced air furnace with ducts ran to the floor level at the far corners on either side of the OH door. This brings the shop up to a comfortable working temperature in a short time and it's very even heat floor to ceiling. But it wasn't cheap having all that installed.

[Jim Becker]

I don't have radiant, but I'm "more than pleased" that I invested in HVAC for my shop for four season comfort. I don't make it "cold" in the summer and "hot" in the winter...it's just plain comfortable to spend a lot of time out there now. Of course, being fully insulated now also factors in. I went mini-split for my installation and it barely blips our energy bill, unlike the resistance heat I used to use.

[Jack Frederick]

Most of the gas fired wall hung boilers have an electronic low water cut-off built in. When I built my 30x34 shop I considered radiant. I have been in the business most of my life and can buy wholesale, get the boiler for free and install it all myself. I chose not to do it for cost reasons, but most importantly the way I use the shop. My use is intermittent. Therefore, it was best, for me, to go with the Rinnai DV wall furnace. Radiant is great if you are maintaining temp all the time. It doesn't really do will with set-backs. Radiant is wonderful heat but I'm happy that I did not do it in the shop.

[Kris Cook]

Am envious especially this morning as it is 10 degrees outside. I have a 1,500 watt heater going in the uninsulated shop/garage to try and keep some of the chill off. It was 28 degrees in there this morning, so doing a little good. I am going through the propane thing right now and am sitting here messing around on the computer waiting for the shop to warm up. Radiant heat sounds nice although wouldn't have worked for me. Planning to get the wood stove going this week so I can work out there when I have time.

Enjoy your warm shop.

[Mark Blatter]

Am envious especially this morning as it is 10 degrees outside. I have a 1,500 watt heater going in the uninsulated shop/garage to try and keep some of the chill off. It was 28 degrees in there this morning, so doing a little good. I am going through the propane thing right now and am sitting here messing around on the computer waiting for the shop to warm up. Radiant heat sounds nice although wouldn't have worked for me. Planning to get the wood stove going this week so I can work out there when I have time.

Enjoy your warm shop.

Hey Kris - I know what you mean. I lived in Helena for many years and had a big unattached garage that wasn't heated. My father pulled a pellet fireplace out of his house and gave it to me. I installed that in my garage and it was so nice, but I ran through bags and bags of pellets. There is nothing like a cool fall day in Montana.

[Kris Cook]

There is nothing like a cool fall day in Montana.

Ha.

Seems more like January right now.

Supposed to be back up in the 40's by the end of the week.

[Bill Carey]

I have a mini split system as well in the second floor office over my shop. During the summer I keep the door open with a box fan blowing cold air downstairs and it keeps the shop nice and cool. I have an electric ceiling mounted heater in the shop that is VERY expensive to run, so I'm in the process of installing some duct work and a used blower to take the hot air off the ceiling of the office and blow it down to the shop floor. Hopefully that'll help some in keeping the elec bill down. It'll cause the split system to run more but it is much cheaper than the ceiling mounted unit to run.

[Kris Cook]

Bill - I also have a second floor office above my shop (still trying to get completed). If you had it do do again would you have sized your system to allow a second air-handler from the mini split in the shop downstairs? That is what I am planning to do and am curious what your thoughts are.

I will also have a wood stove in the shop below the office.

[Bill Carey]

Hey Kris - when we bought the house the shop/office was done, so I didn't get a choice. But were I doing the work now, I think I would go with a high efficiency HVAC system. The nature of the work means there is very little duct work, and natural gas is the best option here. And it would save a 220 circuit for the shop - always nice to have. Wood stoves I have no experience with but they make me nervous. Wood shop and fire are not words that should be in the same sentence. IMHO.

[Thomas Eustis]

I am just finishing up a stick built 28x40 shop with 10’ ceilings (should have the CO in a few days). I kind of went all out with 7” concrete floors, in-floor radiant heating powered off of a super efficient natural gas on-demand hot water heater (Takagi), bathroom, a small office, and an 8/12 pitch so the attic is huge. Also added 10 8’ LED fixtures (88k lumens) and a 8x12 R19 garage door, and finished it with board and batten. Looks awesome. BTW, I went WAY over budget...

I still have not cranked up the floor heat (waiting on CO) but if you are pouring a slab it makes sense to get the tubing in the slab. You’re only going to pour the slab once. For my shop the 1000’ of 7/8” tubing was only about $1k. I used a system designed by The Radiant Floor Company in Vermont.

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[Lisa Starr]

Thomas - go easy when you turn the heat on in the new shop. If you warm the concrete up too quickly, it is much more likely to crack. Also, depending on how it is set-up, consider lowering the supply water temperature while you are first warming it up.