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Chase Plumber
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Thinking about when I build a house later on (if the good Lord is willin'), that I may just install a seperate, maybe 20gal w/h for a radiant floor with a recirc pump.

Anyone know what would be best to use, e.g. copper or pex?

Also, how about doing the floor construction? I figured I could maybe notch each floor joist, maybe 1" deep and lay the pipe in it. . . Would that be enough to keep the heat on the sub-floor side, instead of the heat escaping downwards?

I'm really trying to get away from buying some kind of insulation board to put up against the bottom of the floor joists.
 

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Master Plumber
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Thinking about when I build a house later on (if the good Lord is willin'), that I may just install a seperate, maybe 20gal w/h for a radiant floor with a recirc pump.

Anyone know what would be best to use, e.g. copper or pex?

Also, how about doing the floor construction? I figured I could maybe notch each floor joist, maybe 1" deep and lay the pipe in it. . . Would that be enough to keep the heat on the sub-floor side, instead of the heat escaping downwards?

I'm really trying to get away from buying some kind of insulation board to put up against the bottom of the floor joists.
A 20 gallon heater will only warm a small section of floor. It won't heat your house.

How you gonna nail your subfloor down?

You need to put insulation under the floor. No way around it.
 

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yeah, notching a joist is never a good idea. and ive done alot of in floor heat as far north as i am and id recommend either wirsbo's hepex or the watts radient pex ive had good luck w/ both. if your gonna use a water heater as a heat sorce, and i would not recommend it you would be better off w/ a power vent , or a rinnai otherwise in the cold months your elec meter is gonna be spinning. and yeah insulation is a must and a 2" air gap is recommended between the insulation and the pipe,
 

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Water heaters AFUE is about 60%, boilers run from 85% and up.

A water heater might last ten years, a boiler will last as much as 50.

Water heaters are NOT made for the demands of heating, you likely void warranties, and will cut the life expectancy by using them for heating.
 

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What ever you do, don't go the electric water heater route. The operating efficiency is terrible and pretty much un does any energy savings from the radiant. Use a viessmann or Buderus or Weil Mclain or for that matter any one of hundreds of high efficiency mod con boilers for the job.
 

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how is the operating efficiency not good ? i am all pro gas.. but thats becasue of ease of installation and its all ours and not sparky's lol . but to call something electric un- effiecient is kinda silly. by defination. it is the most effiecient. period( may not be the cheapest... depending where you live etc but still not the point) anyways. you have so many options with heated floors. wholehouse. if you have the cash boiler.. forsure. and if you just paying for material and installing it yourself its the best way to go an to learn alot. another way. instant heater.. on loop with storage tank atleast 50gal. is cheaper but only because it is an open system which also come with sacrifice's ( less longevity) then boiler system. an upside.. less components. easier to do on your own. or yes you can use hwt but. the in floor heat is usually always supplemental heat. * where i live atleast* because you have to consider air exchange an humidty levels etc. i find that combination of air/floor heat is the works the best for comfort and wallet. you cant get hydronic quotes and schematic from any wholesale that has hydronic install cert's and usaully best to talk to about common methods for region. as for floor heating. depends on how you look at it. staple up ( in between joise's) an insulation underneath... is a hassle but it works but best method... on top of subfloor with insulboard layout.. an then thin set ( self leveler) over top. but then you run into a problem with the wieght load on the floor it self. so many options. from quick an easier... to thorough and best quality
 

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you cant get hydronic quotes and schematic from any wholesale that has hydronic install cert's and usaully best to talk to about common methods for regio

meant to say you can =)
 

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Try A Rinnai & Heat Box By Navien If Your Sq Footage Not Too High. Otherwise Boiler, Transfer Plates And Insulation Under Floor Joists Best Way To Go.
 

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if your that worried about saving money I personally would just use radiant baseboard, and if you are going to have a basement then radiant floor in the slab..

notching out floor joists is NOT a good idea unless you like poor heat and squeaky floors..
 

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... boilers run from 85% and up.

Boilers start at 80% which is a government mandate. Soon it will be raised. I can't remember to what though. 87% seems to come to mind...



OP - I'd think you could install your own boiler for about $2,000. Get a good used one for free and rebuild it for $500...
 
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