New Build

JCHJ

I am new to the website and I an anticipating a Barnado build in Eastern MT this spring. I am working with a great contractor that, like me, has not installed radiant heat but is more than willing to do so. I want to do this install and would like to keep it "KISS", if such applies to radiant heat flooring. I have done some research and will continue to do so to educate myself and I am curious as to if I need to break two anticipated heating zones into 4 or more (2 each (shop/living area) due to square footage) ? The build will have a 60x40 shop area with the adjoining living area 30x40. The upstairs and downstairs will also utilized mini split units for cooling and added heating capacity. I assume 1/2 pex is appropriate of do I need to go larger? Do you have suggestions on a boiler for the application? The contractor will insulate the footings and slab with 3 inch foam. The build will have 16' sidewalls and insulation will be spray foam throughout (other than the slab).

I appreciate the feedback and I will continue to peruse the web for information that is available. Some information I have found it seems to be controversial and contradictory, while some seems basic and accepted. Thanks in advance for any input and advice. Jim

jesmed1

While you're waiting for answers, you may find these previous threads useful:

https://forum.heatinghelp.com/discussion/182265/radiant-heat-system-in-1050-sq-ft-barndominium?utm_source=community-search&utm_medium=organic-search&utm_term=barndominium

hot_rod

The first step is a heat load calculation for the various buildings/ rooms. Then choices like heat emitters, boilers, tube size come into play. Step two is the design of the system based on the loads.

You can try a load calc yourself, many wholesalers do them as well as reps or the radiant tube manufacturers directly.

Them Uponor design manual would be a good first read. It takes you through the steps.

https://blog.twinsprings.com/wp-content/uploads/2013/05/Uponor-Radiant-Heating-and-Cooling-Design-Assistance-Manual-Part-1.pdf

DCContrarian

In terms of "keep it simple," these systems have to be designed. There aren't rules of thumb you can follow that will guarantee a satisfactory result. Rather, we get people here all the time with systems that don't work well because they were never designed.

The three biggest sources of dissatisfaction:

1. The floor can't put out enough heat to keep the building warm. A subset of this is that the floor can put out enough heat, but only when it's uncomfortably hot.
2. The floor can't change its heat output quickly enough to keep up with changes in the heating load, so it overshoots and undershoots the desired temperature.
3. The floor puts out enough heat to keep the building warm, but at such a low temperature that the floor isn't noticeably warm and doesn't give the "toasty toes" feeling that was expected.

These are all things that can be predicted at design time, if the system is designed.

Hot_water_fan

Something to keep in mind is that as building quality increases (specifically as the number of holes in the walls decreases), floor temp required decreases.

leonz

https://forum.heatinghelp.com/discussion/200768/new-build

Using overhead steam would be even simpler for you as the properly sized steam boiler with a drop header and radiators would provide you with the heat you need with much less plumbing work.