Another in-floor heat question

[Herkster5]

Needing to pour cement in my 540sq ft detached garage and am thinking that while I have the opportunity, I might as well put a drain and in floor heat in it as well.

What is the best route to go? I have options of hooking up to the cities LP (yes, you read that right, my little town runs on LP and not Natural Gas) or using electrical.

This garage is going to be more of a work space than just a place where I park a vehicle, so the constant temp would probably be kept near 60. Living in Iowa, we will run into real temps under -10, windchill quite a bit lower.

Assuming LP is the best route, but I'm more curious of how big of a boiler would be required? I've read and read but sometimes it is easier to start a conversation about exactly what I'm looking for and see what people ideas are.

Thanks!

 

[theoldwizard1]

WOW ! Slow down !! Lets talk insulation first.

You need at least 2" of foam board in the floor, 4" would be better. That foam board need to run down the inside of the footer.

Minimum of 4" of fiberglass or cellulose or mineral wool in the wall. Better yet, build the walls with 2x6, spray foam 2" to the inside of the sheathing and then install the rest of the insulation.

Ceiling should be 12" of blown in fiberglass or cellulose.

I have no idea what LP costs. I know in many locations, where people have their own tanks, the cost goes up and down a lot depending on the time of the year. I hope your town gets a better rate. Natural gas is almost always cheaper than electricity, so I have to assume the same is true for LP.

 

[Jackfre]

Don’t want to rain on the radiant parade, but you could go with a Rinnai EX22 direct vent wall furnace, be very comfortable and spend about two hours installing it. You will be very comfortable.

 

[Herkster5]

WOW ! Slow down !! Lets talk insulation first.

You need at least 2" of foam board in the floor, 4" would be better. That foam board need to run down the inside of the footer.

Minimum of 4" of fiberglass or cellulose or mineral wool in the wall. Better yet, build the walls with 2x6, spray foam 2" to the inside of the sheathing and then install the rest of the insulation.

Ceiling should be 12" of blown in fiberglass or cellulose.

I have no idea what LP costs. I know in many locations, where people have their own tanks, the cost goes up and down a lot depending on the time of the year. I hope your town gets a better rate. Natural gas is almost always cheaper than electricity, so I have to assume the same is true for LP.

We'll have insulating under and around the slab before the cement is poured. Our LP is at a better rate due to the city buying it in bulk vs a normal 500 or 1000g fill in a tank that an individual would own.

And yes, LP is going to be a cheaper heat source than electric.

 

[PNWguy]

If budget is a concern, you could probably get away with a LP water heater. You're not heating much of a space - assuming your wall & ceiling insulation is good.