Need this groups help. I am having an addition built on to my shop (addition = 21'x60'). The addition will probably be subdivided into half rec room (billiard table & pinball collection) and half metal hobby shop.
Now would be my chance to install radiant heating into the new cement slab. Any comments on doing this. My concerns are as follows:
Is it expensive to operate? (I have electricity and propane available)
Is it the right technology if, say for instance, I am going to my shop for only a few hours at a time.
I am in the Portland, OR area. Any comments from users of radiant heat would be really appreciated.
Radiant heat can be more efficient than convection or forced air, but you have to figure out the fuel cost per BTU- usually electric is highest, followed by propane. Even an efficient heating system can be overwhelmed/negated by an expensive fuel source.
It will take some time to heat up the mass of concrete. If you want to keep it at some low level all winter it would probably be ideal since the machines will stay warm and it will be comfortable at a lower temperature than if you are using forced air. If you're going to turn it off altogether while you're not in the shop it won't be appropriate.
Put the tubing into the pour even if you think right now that you'll use something else for the heat - the tubing alone does not cost much, and it's much harder to do later if you change your mind.
Put a propane water heater on it, unless electricity is very cheap (perhaps with an off-hour (night rate) water heater, it might be - usually it's not). If you have a night-rate heater, I'd use a programmable thermostat to run up the heat in the floor overnight, then let it coast over the day. I suspect running cost depends more on overall building insulation than radiant or not.
Yes and no - keep the radiant set at 45 or 50 to keep the shop dry, use something else for quick heat (if needed) - response time is fairly slow, as you need to heat the slab, which is massive. 45 or 50 is fine working conditions when outside is cold, IME, but DWYL. If you know in advance when your few hours will probably be, you could have a programmable thermostat get it up to whatever you like to work in.
I got tubing from
- seem alright, have pretty good information available for download, just a happy customer. Shop around and see what you can find - your local plumbing and heating supply probably has some tubing as well. Bigger tubing pumps easier than smaller tubing, especially if you are using antifreeze.
larry g wrote: (clip) Don't discount solar heat here. If you are out of the trees and get even moderate sun your heat will cost pennies. ^^^^^^^^^^^^ This is an important suggestion. Since the operating cost will be near zero, you will be willing to keep the shop warm even when you're not using it. In a situation with large thermal mass this is important, because if you have to go out and work for several hours in a cold shop while the heating system tries to "catch up," you won't be happy. Also, in order to keep the shop dry, you will need the heat on even when you're not there.
My guess is if you do a cost analysis, the system will pay out in a few years.
I bought a house with a detached garage, all concrete block, 2+1 bays. That is, the garage, not the house. It never had a concrete floor poured. I am excited about putting in new floors plumbed for hydronic radiant heat. I've talked to people who have it, and they seem absolutely thrilled with it. I worked in our family machine shop for 15 years with forced air heat. Anyone from this group who has worked in this environment during below freezing temps know how miserable it is when your feet get cold. Early last winter we installed a gas fired ceiling radiant heat system we bought second hand, and WHAT a difference.
The plan for the garage is to plumb the floor for water, then immediately install a gas hot water heater and recirculating pump. I also have the gas fired 90%+ efficiency forced air furnace from my previous home. (yeah, the furnace was much nicer than the house, but that is a whole other discussion) As time permits, I plan to develop multiple boilers, wood, waste oil, and maybe tinker with direct solar as well. If I can come up with a feasible, reliable boiler, I'd also like to supply heat to the house and supplemental heat to the upcoming hottub.