Staple up conversion

redwing

I am a contractor and I hired a plumbing contractor to convert base board heat to staple up in floor for a customer of mine. The plumber unhooked from the old base board and tied into the loop for the in-floor and called it good. I have been led to believe that a mix valve and manifold system should have been installed. I would like to hear opinions on proper hook ups please. Thanks in advance.

Gordan

Describe the staple-up

Stapled directly to the subfloor, or suspended tube, or were heat transfer plates used (and which ones - stamped or extruded.) Also, what's the heat source, and what supply temperature is it set for?

redwing

Staple up conversion

Thanks . Its pex tubing stapled right against floor with r-38 foil insulation over. burnham boiler water supply temp is 180  I believe.

Gordan

Some more questions...

What spacing? What tubing - what size, does it have an oxygen diffusion barrier, what are the loop lengths? What flooring is on top?



In short, you've got cause for concern. Uneven floor heating and thermal expansion noises are a possibility, and so is flooring damage. In addition, the output of this kind of system is typically limited. Have you tried to use this yet?

redwing

more specs

Thanks Gordon for answering. Its half inch red pex spaced approx. 10 inches apart. Two zones one is 300ft long and the other 320ft. Subfloor is 3/4 t&g osb with carpet.

redwing

more

Sorry Gordan , There isn't any oxygen diffusion barrier. The plumber told the home owner he could save himself some money by handling the staple up portion himself. Home owner had worked briefly for a plumber years ago so was not completely inexperienced. He did not staple the ends of the runs up where the loops are as he thought that might cause noises from expanding and contracting.

redwing

more

Gordan , The pex that was used does have an oxygen diffusion barrier. Sorry for the confusion

Gordan

The fact that the homeowner stapled the tubing is not in itself a problem

I'm a homeowner, and I not only ran the tubing, but installed my entire space and domestic water heating system - but I designed the system before installing it. That means that the boiler, the tubing, the circulator and the radiant panels are all chosen and configured to work with each other, and the whole kit and kaboodle is designed to meet the heat loss in each room. Was a heat loss calculation ever done? What were the results? What is the boiler rated output?



This probably feels like I'm asking a lot of questions and providing few answers, but... TYPICALLY, for staple-up, transfer plates are used unless not very much heat output per square foot is required (that also addresses heat striping, where the floor directly above the tubes is much hotter than the area in between)  AND narrower tube spacing is used - 8". TYPICALLY, lower supply temperatures are used - OR the tubing is suspended in joist bays a couple of inches below the subfloor (that would also decrease heat striping.) TYPICALLY, if low return temperatures are expected and a conventional non-condensing boiler is used, there's some kind of protection for the boiler from too low return temperatures so that it doesn't corrode away. TYPICALLY, loops are shorter to prevent too much temperature drop from one end of the loop to the other, and to prevent too much pressure drop. TYPICALLY, there is accommodation of potentially different flow requirements for the boiler, and the radiant tubing. These are typical practices and one can do things differently, but they should have an idea of what they're expecting to happen.

NRT_Rob

first

before anyone converted anything it should have been ensured that radiant could do the job: room by room load calculation, if there are multiple rooms.



second, for any massively high temp radiant like this a mixing valve and outdoor reset control would be strongly recommended for better efficiency as well as floor comfort.... in fact, with this method, if it's "beefy enough" to meet your heat load, all of your existing baseboard could move over to the other side of a mixing valve as well and you could really improve boiler performance and comfort in all areas.