Radiant Floor Heating ..Questions

[Dix]

I've got one area of the house, that's hard to heat with both stoves. There are some insulation, caulking issues to be done,not major, and will be addressed before winter.


The lower middle of the floor plan, labeled 10" X 15". It's way bigger than that.

There are 14' ceilings on that level, and it's on a slab, with baseboard heating. It is on the same zone as the apartment (right side of floor plan). I have a 4 zone oil burner, 2 zones used. The oil burner is located in the basement, to the left side of the bedroom 19' 6" X 11' 2".


If I install radiant floor heating off of an open zone on the oil burner, boxing out the current floor to add another floor on top of that (I'm thinking ceramic tile, with plywood underlayment, etc)running pipe (copper, pex?) under the new floor in a loop, on it's own thermostat set at say 62 F during the dead of winter, would that be feasible?


I have to repair a few broken pipes on this level. They froze over the winter, and the carpet is ripped out. It's at the best place it can be for a thought like this.

Let me have it

 

[jimbom]

PEX for sure. Blueboard not plywood, beneath the slab. Minimum of two inches of perimeter insulation between the slab and surrounding walls. Minimum floor temperature of 68 °F or it will feel cold. If you are going to make it one zone on six inch centers, use 1/2 inch PEX with the warmer water started at the perimeter. The above should be enough for you to scope price this option. If it fits into the budget, there are some decent design guides on the net that would help you refine what you need at your location and specific building.

 

[dave11]

To be sure you're getting where you want to be, you should do a heat loss analysis for the area in question. There are online resources to help with this, or it can be done by hand, following a few directions.

Adding a new floor and all the plumbing etc is a big job, for a space not all that large. Why not add a freestanding hot water radiator to the room? Simple to install and plumb, compared to subfloor heat. Much cheaper overall, and will do the job. Many modern radiators are very decorative. It won't make the whole floor really warm, like subfloor radiant would do, but it will make a big improvement.

 

[dave11]

Or can you alter the current radiators for more heat output? Are you sure they're getting proper flow?

If that room is reasonably insulated, a small electric heater used at need is way cheaper in the long run than redoing the floor and adding pex.

 

[jimbom]

I agree with Dave11.

 

[Dune]

No matter what, you can't use copper Eileen. Pex is much cheaper anyhow. You can't really just run it off an open zone, your regular heat emitters operate from 160F and up, radiant is from about 80-140, so you need a mixing valve at a minimum. It is actualy a pretty expensive job, especialy to retrofit. One cheap way out, especialy if you want tile floors and the area is small, is electric mat in floor radiant. Check into that before you make any final decsisions.

 

[Dix]

To be sure you're getting where you want to be, you should do a heat loss analysis for the area in question. There are online resources to help with this, or it can be done by hand, following a few directions.

Adding a new floor and all the plumbing etc is a big job, for a space not all that large. Why not add a freestanding hot water radiator to the room? Simple to install and plumb, compared to subfloor heat. Much cheaper overall, and will do the job. Many modern radiators are very decorative. It won't make the whole floor really warm, like subfloor radiant would do, but it will make a big improvement.

I just want to heat the space, at the least expensive level. I've pondered wood, coal, and propane (the gas tanks are at the corner of the master bedroom, lower left).


If I have to heat the space off of the oil burner, I need to create another zone, piping, etc included. It currently is on the same zone as the apartment, which has the Englander NC-13 wood burner.

 

[Dix]

No matter what, you can't use copper Eileen. Pex is much cheaper anyhow. You can't really just run it off an open zone, your regular heat emitters operate from 160F and up, radiant is from about 80-140, so you need a mixing valve at a minimum. It is actualy a pretty expensive job, especialy to retrofit. One cheap way out, especialy if you want tile floors and the area is small, is electric mat in floor radiant. Check into that before you make any final decsisions.

Electric is so expensive here. That's a problem. I'm trying real hard to cut back on it, where ever possible.

The issue is that I want to avoid the problems we incurred this winter. I've never had pipes burst before >:-( I'm more than willing to drain both heat zones, and add anti freeze, or what ever needs to be done, if I can heat that area reasonably).

Pellet stove? Gas stove?

I dunno.

A seperate zone to an old fashioned huge radiator off of Craig's list? I've thought of that, too :blank:

 

[Dune]

Is the oil burner running full time? Have you tried to heat the area using fans to move air from the warm areas?

 

[Dix]

Is the oil burner running full time? Have you tried to heat the area using fans to move air from the warm areas?

The oil burner hasn't run since last year. Worst case scenario is a new tank, and lines run. Don't have the $$$$'s right now.

I added an electric HWH last June. Showers & dishes. Laundry is done in cold water.

This past winter was the first with the NC-13. The lay out is weird. I have ceiling fans all around, and we've tried combo's of floor & ceiling fans. Can't move the heat. I've thought of opening the area over the doorways, and adding transoms.

Kinda of 1940's look %-P