Radiant Floor Heat

[HummerHippy]

Hi all -
Just bought a house. Am planning on putting in radiant floor heat (pex tube with hot water). just wondering if anyone had experience with it. Likes, dislikes? I know there will be no duct work to add A.C. and that it takes hours to initialls heat up and it's a long process to change the temp in the house. But other than that...? Any feedback is appreciated.
Thx.

[RubHer Yellow Ducky]

you can still have A/C...Is this house already built or is it being built ??????

If the house is already built I would add it to the bathrooms, kitchen & garage floors only. I would still want Central A/C and I would put a Wood Burning Stove (adaptable to pellets) in the basement.

[KenP]

I've heard nothing but good things about radiant heat. Being that far north, I'd run it in the garage if possible.

[DRTYFN]

President Bush has radiant heat in his Crawford, Texas place. You better not get it or even acknowledge it.

[HummerHippy]

Originally Posted by DRTYFN

President Bush has radiant heat in his Crawford, Texas place. You better not get it or even acknowledge it.

HA!!

House is 75% done. Conctrete loors alreay poured and walls, roof etc are up. Interior walls need sheetrock. All floor joists are open so puttting in the tubes now is "relatively" easy/painless. So cant put it in basement or garage. owner was having it built and then decided he didn't want it. So there ya go.

I've heard good things too, but wondered about it. Never experienced it first hand. Its a log home, so I figured radiant, once it heats everthing up, would be the way to go.

thx

[DRTYFN]

Just do what Al Gore does - turn up the electrical heat.

[working Hummer]

I work at a HVAC company and Pex infloor heat is the best there is, unfortunatily you want it under the cement floor. We hardly ever put any in the floor joists. Heat rises and putting it in the floor joists would be a waste of money (won't heat lower level) I'm assuming you have a main floor and a below grade basement? I'm not understanding the no ductwork? If you put infloor heat in you still need ductwork for the heating and cooling. If you could of put the pex in your lower level cement you still need the main floor heated. Floor heat in your cement does not heat the upstairs level, it will bring up some heat due to heat rise but not to heat the main level. Depending on the size of house you will need either a electric or gas boiler to run the floor heat. A duel element water heater will not do it. This is an awsome but expensive system to put in but as I said before it's a comfort kind of heat not the main sourse for the house. YOU STILL NEED HEATING AND COOLING. Good luck! If your house is a slab on grade house then disreguard most of what I said but you will still need a heat sourse for the infloor and an airhandler with backup heat in it, an A/C and DUCTWORK.

[RubHer Yellow Ducky]

Originally Posted by HummerHippy

HA!!

House is 75% done. Concrete floors already poured and walls, roof etc are up. Interior walls need sheetrock. All floor joists are open so puttting in the tubes now is "relatively" easy/painless. So cant put it in basement or garage. owner was having it built and then decided he didn't want it. So there ya go.

I've heard good things too, but wondered about it. Never experienced it first hand. Its a log home, so I figured radiant, once it heats everthing up, would be the way to go.

thx

Ok...now your giving us more info...

Floors are already poured, TO LATE...tubing needs to be put just below the surface of the concrete to be effective...for basement you can put tubing in and then pour a cap over existing floor but for any upper floors you MUST BE VERY CAREFUL IF YOU TRY IT. THE SUPPORT STRUCTURES MAY NOT TAKE THE EXTRA WEIGHT...putting the tubing under the existing pour is a giant waste of money!

I have been studying log homes for the past 2 years as i'm planning on having one built in N.W. Georgia. They are super at insulating...as i said you, you will want central A/C and look into a wood burner (pellet also) for the basement. For the normal 3 story, Main level, second level or loft plus a basement, you put the wood burner in the basement which really heats it up, it radiates up through stairwell to main area for perfect daytime and evening living and then whats left raditates up to the bedrooms for cool nightime sleeping !

[HummerHippy]

Perfect. Thanks for the advice!
basement - below grade had concrete floor, no tubing so will heat with wood stove for now. First floor and second floor, 12" floor joists are open from below. (remember it's 75% finished). So will need to run the pex under the 1st floor subfloor (access from below - basement ceiling). Then, from what I am learning, you insullate the floor joist space to direct the heat back up into the first floor structure, and that should heat the first floor. Same thing with 2nd floor, although as heat raises, probably wont need to use 2nd floor heat much.

I'm diving in head first!!! Thanks all! I'll let ya know when the house warming party is

[HummerHippy]

Working Hummer -
Do you have any experience with Rinnai boilers (being suggested by plumbing company) or Triangle Tube's Prestige stainless Steel boilers (recommended by a heating contractor's quote)?

[KenP]

Originally Posted by HummerHippy

So will need to run the pex under the 1st floor subfloor (access from below - basement ceiling). Then, from what I am learning, you insullate the floor joist space to direct the heat back up into the first floor structure, and that should heat the first floor. Same thing with 2nd floor, although as heat raises, probably wont need to use 2nd floor heat much.

I'm diving in head first!!! Thanks all! I'll let ya know when the house warming party is

READ FIRST!

Radiant heat tubes go in the concrete so they can heat the thermal mass of the concrete. In the floor joists doesn't work without help and labor.

Since the concrete is down, you can use a thin layer of concrete above the wood framed floor and embed the hydronic tubes in it. It's not as efficient as a thicker, full width floor of concrete, but it does work.

As for heating the water (or glycol), if you don't want to use a boiler you can use solar energy.

You can use electric mats under your finished floor, but I wouldn't.

Since your floor is down your choices are limited. You could go with Warmboard, but it's not as efficient as heating the concrete mass.

Then there's GCS Radiant that uses grids made with a concrete mix.

However, this is the stuff I'd use, Crete-Heat, or something similar. The mats are insulated and you just lay the concrete, or thin-set on top, then the finished floor. Plus it's a one person install.

[HummerHippy]

Thanks Ken. 1 thing I wasnt clear on, I guess, the finished floors are not down. Only concrete in the basement, and then wood subfloors on 1st floor and 2nd floor.
I understand the idea behind a poured concrete mass on the first (and 2nd floor), but weight etc, I am not sure I can do that. I thought I've seen and heard about putting the tubbing attached to the underside of the wooden subfloor to heat the whole floor, and with insulation below the tubing in the joists, it would direct the heat back up to that floor as well.

But you all are saying the best way to do it, is a poured concrete layer with tubing in it, on the 1st floor?

[KenP]

Both floors.

If you're set on putting the tubes undet the subfloor of the second, then put a metal shield under the tubes to direct the heat up.

[TRUBRIT]

I also have researched this regarding a Timber frame home. In your case the Warm boards will be more efficient as they will be on top of the joists and will direct the heat upwards. Your finished wood floor will go on top of this. A concrete floor on top of the joists would not be feasible due to the weight. Hanging the tubes under the joists is used a lot when people refurbish old houses and they already have a finished floor on top of the joists which they do not want to change. As stated, you would have to add insulation to direct the heat upwards through the finished floor if you choose to hang the tubes under the joists.

[HummerHippy]

Ken -
Yes, I've heard about the aluminum plates with a channel for the tubing to sit in. But with no finished floor down yet, I think putting the tubing above the subfloor would work better. Thx guys.

[KenP]

Originally Posted by HummerHippy

Ken -
Yes, I've heard about the aluminum plates with a channel for the tubing to sit in. But with no finished floor down yet, I think putting the tubing above the subfloor would work better. Thx guys.

I may have misunderstood a prior post of yours, but yes, above the subfloor is preferred as I stated in post 11.