Staple up Radiant advice

If you do use plates you may be able to get by with a lower water temp.
Some of the benefits with lower water temp are.

1. Water storage lasts longer bigger temp range.
2. If you have a gas mod/condensing boiler more condensing better efficiency.
3. Easier to use solar if your temp requirement is lower.
4. Regular oil/gas boiler will run a little more efficient at a lower temp.

Ethan

I have radiant on the first floor of my colonial with large family room attached. My plumber who did an excellent job just stapled it up (not PEX either) he used the rubber with metal core, I think it was a Goodyear product but not sure. Then placed foil faced insulation between the floor joists to create a 4" air pocket for the heat. He ran 2 runs in each bay, and doubled up a bit near large windows. Tied it in with a Tasco maniford/ mixing block with its' own circulator. Works well. Not sure how the plates work or how much better though, just know what I have. I have pictures if you want me to send them to you.

Kevin

I have many succesful staple up applications running in my climate ( zero degree design oat) most without supplemental heat. We use a lot of 3/8 pex tubing and FF R-19. We do take extra precautions to seal up band joists etc. In one instance where the computer said it would work but in reality it didn't we installed extruded platesand that helped trmendously. This wa a bathroom with not much surface area, but 2 exposed exterior walls. It can definitely be done, but the plates definitely make a better job.
Good luck

Yes, a recent job was 22 btu/ sq ft. Our installs are typically 8" oc and we try and keep our loops a180' or less. HR says that the reflective value of the FF insulation will be lost once dust accumulates, andI believe this to be true.
Chris

Siegenthaler says to put 10 times more R value below the tubes than above the tubes: real long term R value, not miracle foil values. As much as this hurts down where my wallet lives I am going to follow that rule for my install because it sounds like the long term best thing to do.

I have 2 layers of 2" polyiso under my suspended tube. First layer at required distance from fins second layer applied perpendicular to first with 3/4" air gap. Spendy but worth it for the long run.
Will

I have seen my local builder use stuff called Polar Rap it is sold at the local lumber yard, it is an insulation used to go on before vinyl siding installation. The stuff is incredible It comes in an accordion about 4 feet by 40 feet long, you just rip it down on your table saw for the with you need. It is foil on one side and plastic on the other side with Styrofoam in the center. It can bent, beat up and forced into place in your floor joists without breaking. 1/4 inch has a R factor of 1, and they do make larger sizes. Just put the foil side up and away you go.

Bob