PEX in floor, loops and lengths

[robg222]

900 sq. ft. With 12 ft. ceilings, 1 10x10 overhead door and one man door, no windows. Im in NE PA, temps down to 0° from time to time. Don’t have an insulation plan yet, but will be well insulated. New to all this, want to get started and get tubes in foundation regardless of other variables if possible. I understand a foot of 1/2” PEX per sq. ft. Floor area, but not much more than that at this point.

Would there be anything wrong with laying 3 300’ loops (approximately)? I know some say loops should be less than 200’ or so, but have also read that this is not true.

Been lurking here a long time, any help would be greatly appreciated.

 

[86turbodsl]

This has been covered many many times, but in a nutshell, to make your life easy, keep all your loops the same length, and definitely 300' max. You'll have a pretty decent delta T by the time you get through 300'. 1/2" pex, 4 loops of 225' would be what i would do, so your floor is all consistent temp. Pump will be cheaper too. If you aren't heating full time, make sure you use an antifreeze.

 

[thoyer]

900 sq. ft. With 12 ft. ceilings, 1 10x10 overhead door and one man door, no windows. Im in NE PA, temps down to 0° from time to time. Don’t have an insulation plan yet, but will be well insulated. New to all this, want to get started and get tubes in foundation regardless of other variables if possible. I understand a foot of 1/2” PEX per sq. ft. Floor area, but not much more than that at this point.

Would there be anything wrong with laying 3 300’ loops (approximately)? I know some say loops should be less than 200’ or so, but have also read that this is not true.

Been lurking here a long time, any help would be greatly appreciated.

About ready to do the same thing 950 sq ft in NE PA. Expecting to break ground in a few weeks after 2 years of planning, variances and permits.

The company I'm buying my radiant floor heating system from provided me with all of the info I need for the layout and installation. You might want to ask your supplier.

Tom

 

[yeldogt]

Radiant is a factor of building load. Building load is size/ insulation/ outside and inside temps. Don't use general rules -- figure out what BTU you need per square foot .. and deliver it. Remember -- insulation under slab is needed to get BTU upward.

Loops match output ... longer loops will have colder water at the end of the loop at start up. Loops further apart will be transferring heat to the slab at a lower rate. long loops and/or wide spaced loops = higher water temps.

The cost to install 3 loops of 300' vs 4 loops of 225' is the tiny extra cost of the manifold -- nothing.

I like to use much more pipe -- lower temps ... faster response .... uniform heat output

 

[robg222]

About ready to do the same thing 950 sq ft in NE PA. Expecting to break ground in a few weeks after 2 years of planning, variances and permits.

The company I'm buying my radiant floor heating system from provided me with all of the info I need for the layout and installation. You might want to ask your supplier.

Tom

Who is your supplier Tom, I will call them, Thanks