Radiant floor in place of radiator in bathroom

Brad White_185

the heat loss of the bathroom (and a safety factor being naked, wet and all), the <i>available</i> floor area usable as radiant surface and the lowest predictable water temperature available.

Do all of the math to assure yourself that you have enough surface and guaranteed floor output at temperature to meet your needs. Remember not to count the area around the W.C. to protect the wax ring. Or use a waxless ring.

Treat it as a "prime radiant source" project and have all of your variables defined. If you treat it as an afterthought, it will perform as an afterthought.


My concern is that you may fall short during any outdoor reset periods tending toward cooler water temperatures, (defined by the main house zone) if not all of the time. You may find that you can at best only supplement the current radiation and wind up less comfortable than you are now.

If you come to an impasse, you may wind up having that one room define your outdoor reset low-limit, higher than it needs to be. Tail wags the dog, the remainder of the house will have to throttle back locally to avoid over-heating.


As Gerry said, definitely run a separate zone. A Roth Mini-Shunt seems to fit a nice niche although I have never used one. Taco also has an entry-level "first radiant zone" package for this kind of isolated radiant application.

You will likely want this to be a master zone, not dependent on the main house. Micro-zoning issues should be evaluated, but perhaps your main house primary zone is constant enough to support the bathroom. My concern here is during night setback, if the bathroom is a "slave zone", the warm-up lag time, warming up the floor mass to a point it heats the space, may not get your bathroom to temperature before the rest of the house. To give the bathroom the lead goes to overheating issues as stated.

I love the tub idea and have done that in my own house, not with fin but with a couple of "victory laps" around the tub void before returning. I wish I had done it more thoroughly and thoughtfully though; the opportunity was there and I punted. A five foot cast iron tub, properly done. makes a nice radiator.

In the end, prepare to enjoy radiant but also you may wind up retaining the radiator or installing a smaller one should the radiant alone leave you with a heat loss deficit. A towel warmer is a good excuse by the way and no one I know of has complained about having one. :)

My $0.02

Brad

MikeAR

Bathroom Remodel looking at radiant in place of radiator

I'm not sure this is even worth the trouble, but I'm remodeling an upstairs bath including the subfloor and considering doing a radiant floor in place of the old radiator. This is on a converted gravity system with a Taco 007 circulator so my 2 concerns are 1) Temp. control and 2) getting enough flow. Any suggestions?

gerry gill

best to

run a seperate zone.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Lyle C

Bathroom Radiant

There is an old style trick I've used a few times with good results, if useing a regular tub use cast iron. Rout the radiator lines behind the front skirt of the tub . Then install a 5 foot piece baseboard element or if a large bathroom double one over the other .But not touching the inside surface of the tub . The first few I installed I put in by-passes but never needed them . No tempered lines, no seperate zones ,no cold tubs.

Ruthe Jubinville_2

Just an FYI

I have radiant in my bathroom floor but because it is a small bath Jerry put in a towell warmer also.
the 2 heated beautifully in the winter but since he added the Indoor- outdoor reset ( or whatever it is called) it does not work real well in the somewhat warm of spring and fall.

Paul Pollets

Oventrop UniBox

The UniBox will easily provide mixed temps for up to 10K Btus of radiant. I've done this many times and if you search this site, you'll find the posts. The radiator is removed and the UniBox is piped from the radiator stubouts to the radiant system. No additional mixing or piping is required. Hopefully, you have access to an Oventrop distributor.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"