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Discussion Starter · #1 ·
I picked up a mountain "cabin" (elev about 8500') right before Christmas. It's' a walk out ranch 1550 sq.ft. main flr.,1000 sq. ft. lower level. The place was a foreclosure, empty for 2-3 yrs.
The place had a boiler and radiant under the subfloor and slab. Most of the lower level is "finished"(more on that in another thread). I can see some of the pex in the crawl space area, stapled up with a brass colored wide wire staple. I found 2 of the lines under the slab, frozen and broke thru the top of the slab.
Here is my plan: Main floor
Remove the entire basement ceiling to check the lines
Air test for leaks
Check the length of each zone
Secure the lines with better staples and insulate
Basement slab
Air test each zone, I know one is already broken. If the others pass, I'll repair the broken lines. If they don't, then the plan is hot water baseboard for the lower level.
I'll take all the advice I can get. My heating friend is working on his catamaran in FL. till April.
 

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Future Post Deleter...
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Air test it and go from there.

Use talons.

Hopefully things work. Would be a shame to not be able to use the in-floor.
 

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First a proper heat load to determine if a staple-up radiant floor heating system will heat the space. We abandoned the practice many years ago here in Minneapolis, since such system are inherently inefficient and sometimes simply won't keep up with the heat load.

Since most of our work includes condensing boiler a high temperature staple-up would not be ideal. We do quite a few sub-floor heating systems but always use heavy extrude aluminum heat transfer panels, increasing output to 175% of the bare tube staple-up.
 

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diplomat
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First a proper heat load to determine if a staple-up radiant floor heating system will heat the space. We abandoned the practice many years ago here in Minneapolis, since such system are inherently inefficient and sometimes simply won't keep up with the heat load.

Since most of our work includes condensing boiler a high temperature staple-up would not be ideal. We do quite a few sub-floor heating systems but always use heavy extrude aluminum heat transfer panels, increasing output to 175% of the bare tube staple-up.
I've done a few staple ups that heat the space to 80 degrees on a -50 day (tested as an experiment). They are using 1/2" tubing at 8" OC, aluminum around the perimeter, and foil faced insulation below. The structures are well insulated though, which is really what it's all about. And water temps had to be about 170 for that design load, though lower most of the time.
 

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The hotter the design water temperature the more fuel you will use. Many of our European condensing boiler will not operate above 176°F. Naturally, the lower the load the lower the design water temperature. But there is really no excuse for running to 180°F on a modern radiant floor, even on a retrofit it is very rarely needed, even here in Minneapolis; -17 tonight.

I didn't say you couldn't...
 

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diplomat
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We are all oil boilers, so they generally have a minimum temp of 140 degrees, which covers 50 weeks a year. 150 for the other two weeks. 170 for the 80 degree experiment.
 

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We do a lot of wood here and we have a wood/propane south of Soldotna, but it is not about the boiler temperature. We mix down on outdoor reset to get the perfect supply temp. More comfort, lower fuel bills.

But I can't brag about cold to a guy from Fairbanks :).
 

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Discussion Starter · #9 ·
I haven't tested the system yet. I finished tearing out the ceiling and found a few problems. One semi structural , the other involved roughly 3 lbs of dog food raining from the ceiling. The mice were stocking up.
 

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Not to highjack or any thing but is there a good rule of thumb for estimating how much an infloor system costs. You still need a conventional back up right? Im talking the kind embedded in concrete
 

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Radiant heat typically takes longer to heat up a room is the drawback to it. You're going to wait until April to have your friend look at it?
I don't wait, my radiant floors keep the rooms within one degree of thermostat setting. Response time has more to do with climate, insulation, controls etc. than any particular emitter.

I have never seen a drawback to radiant floors, excluding the initial cost, but if you can't afford to be comfortable, I can't help it :).
 

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BadgerBoilerMN said:
I don't wait, my radiant floors keep the rooms within one degree of thermostat setting. Response time has more to do with climate, insulation, controls etc. than any particular emitter. I have never seen a drawback to radiant floors, excluding the initial cost, but if you can't afford to be comfortable, I can't help it :).
Understandable, but he was thinking of putting in baseboard radiant heaters since the underfloor ones failed. Baseboard radiant compared to the fanned wall heaters take longer to heat up a cold room. Either one is just as good at sustaining a temperature, which is what I think you were trying to say when you said "keep the rooms within one degree". This is what a rep at King will tell you, I think any manufacturer will tell you the same thing. But I agree there's no drawback to underfloor radiant heat if it's installed right, other than cost.
 

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When radiant floors fail, we install radiant walls and ceilings. We even install hot water fan coils when we have to. But they are not radiant heat and don't "heat faster" than properly designed radiant panels.

The heat emitter has to keep up with the heat loss.
 
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