Radiant Floor Heat
Anybody have info on radiant floor (hydronic) heat? I am building a custom home in the Pacific Northwest and am interested. I have read the “Literature” but want to know if anybody has real life experience and what they think of it as far as comfort and efficiency.
No, it's never been discussed here. Hope it's not one of them new fangled, hippy-dippy things from you strange people on the left coast...
Did I keep a straight face long enough? It's discussed constantly. Look through the history of this folder or search on "rfh" or "radiant" and you'll find enough that if you print it and burn it you won't need any additional heat for a coupla years. Then come on back and pose additional questions not answered there.
We're in the process of installing a new radiant heated main floor in our next home. This is an existing house rather than being built from scratch with radiant heating as part of the overall design scheme.
Here are some things to consider:
Wirsbo, one of the major mfr's of PEX tubing (the stuff that goes in the floor) requires in their spec a min. of 3/4" cover over their tubing when installed in concrete or lt. wt. concrete fill. If you have an existing house you're retrofitting, all your doors will have to be trimmed and you'll lose 1 1/2" (more or less standard depth for the concrete fill) of ceiling ht.
PEX tubing comes with or without an oxygen barrier. You need to use the kind with an oxygen barrier to protect your boiler and system from corrosion.
My subcontactor/installer of the lt. wt. material will not warrant his material as a living surface - it requires a finished material - carpet, stone, whatever. Any hard surface material such as granit, marble or manufactured tile requires an anti-fracture membrain between it and the concrete infill. The concrete is subject to too much shrinkage over time and thermal movement such that it would ruin the stone or tile floor.
We opted to include a fast recovery water heater that's heated by the heating system boiler using a stainless steel coil in the potable water tank fed from the boiler. The upstairs rooms will have hydronic baseboard heat. All this requires a lot, I mean a *lot* of mechanical space for controls, piping and what not. But if you're a gadget freak like me, you'll love it!
Consider including a heat exchanger/heat recovery air handling system as well. One thing that I was concerned about was that there would be little if any air movement in the house. After living with forced air all my life, I'm looking forward to not having dust and such being blown all around the place but wondered about *some* air movement to prevent stratification and stagnation. These extremely low cfm systems provide fresh outside air through a heat exchanger so you're not dumping energy outside. Well, not too much, anyway.
If you're still in the planning stages, get hold of a reputable, professional hydronic heating company and get them involved. You'd be surprised how much piping this takes. Where in the PNW are you located? Up near Mt. Vernon I can give you two really good names for contractors who do the design as well.
I haven't lived with such a systekm yet but I'm sure looking eager to do so.
Dennis in Bellevue WA
you would be a pleasure to work for. I applaud you.
Remodeling Contractor just outside the Glass City.
I have just finished a radiant system, also in the Pacific Northwest. So far the system is great, I have slabs in the full basement and garage and staple up on the upper two floors. The slab in the basement does a good job of heating the house and I do not have sheetrock up yet. Also on a side note I used blown in fiberglass insulation and there are no voids in the walls, just something to think about.
Thanks for the reply. I have heard and read all the "literature" about this but want to know what real people think. People who are not selling it. If they like how it feels. Cost to operate etc. Thanks.
Sounds like the slab in the basement may heat the whole house? Do you think that will change when the sheet rock goes up on the ceiling?
If I'm not dead by thursday...I'll be roarin' friday night.
As you may have read and this is a fact, the most important factor is that the heating calcs be done by someone that knows what they are doing. If this is not done you will not be happy with the system period. As far as the basement heating the house once the sheetrock goes up, I think it will slow down the heating as I am already noticing the differance since putting insulation up. However the other loops are picking up the load just like they were designed to do.
JasonIf it wasn't for bad luck I wouldn't have Any!
>Sounds like the slab in the basement may heat the whole house?
I'm willing to argue against this if there are any takers. I'd be surprised if any HVAC contractor or M.E. would specify this.
I'm chiming in late on this one. We have a house partially constructed. We live in the basement with only marginal insulation (pretty sad really). We have radiant heat in the slab and our living space is warm and comfy. It is the most wonderful thing on earth. I pushed hard for it too and it was almost thrown out any number of times during budget crunches!
The basement slab would not heat the whole house. I'm pretty convinced based on our situation. Even if the slab could heat the house, it wouldn't be ideal. In order for that to happen, you would need to have the water in the slab really hot. I think it would make the basement uncomfortable.
Anyway, radiant heat it awesome. Everyone is happy....most especially the cat!
Used all the time here in the custom and upper end. Frost line shallow, slabs the norm, hard surface flooring common, so a perfect fit. The more common it becomes, the cheaper it becomes.
Best there is IMHO. No blowing air, constant temps, warm floors as I get my first cup of coffee. Easy to DIY if you get the help of one of the mfgs to engineer it for you....but the plumber that I use sells so much of it he buys it really cheaply....too cheaply for me to bother.
Only thing that you have to do is think about it in the fall. Takes a day or so to heat up the mass. All I do is adjust it from "off" to about 65 as the temps fall off at the end of summer.
It's hard to do something that's not the "norm". No one seems to want to mess with anything that's different. Got a quote today from a roofer. Two metal roof installations. One the "norm". The second, labor only on some cool stuff that I found...no one carries it here. Labor only on the cool stuff was more than labor+material on the normal stuff. Hard to get out of the box around here. If I want to try the cool stuff looks like I'll have to DIY.
I'm just getting to know my radiant heat, and I'm finding new things every day. When the insulation went in things changed. When the plaster got done it changed even more. Heat doesn't rise. If it did, only the planets above the sun would be warm. And as everyone knows. planet earth is off to the side, so if heat didn't radiate in all directions we'd be really cold. Like last winter f'rinstance. It's the hot air that rises, like around radiators or baseboard heating, causing some warm spots and some cool spots in a room. Not so with radiant heat, I'm finding. The warm air just sort of sits there and gently hugs you. So the heat in the basement doesn't want to go upstairs...unless you open some windows to get it moving!
The more tubing you use to distribute the heat, the lower the water temperature can be. And it's a lot more efficient heating water to, say 85 degrees than to 125 or so.