Radiant Floor Heat?

[jodog]

I'am looking for a good price on PEX TUBING. This is the plastic tubing that is poured in concrete wich the hot water is pumped. THANKS for any leeds.

 

[The patriot]

http://hh471.hiphip.com/Templates/frmTemplateK.asp?SubFolderID=31&SearchYN=N

 

[jodog]

Thanks, man thats a great price!!!!You guy's allways come through.



This type heat isn't common around here . Any do's and don'ts

 

[Sled Puller]

Yes!



Go with 5/8 hose.



Don't make your zones too big to to avoid cold spots and have faster heat control.



Do everything VERY carefully and check,check, check it over agan, before the concrete.

(also buy a few splices for the pour, in case if damage)



If you have a cast iron boiler, be sure to get oxygen barrier pipe.



Lots of valves, and lots of breathers.



And much, much more!



Get a few books, and try to find what they agree on.

Don't rush, you won't regret going with this system.



Gene

 

[mwilson]

Just have to jump in on this one. This is becoming a very popular form of heat up here in the woods. Garage owners love it because you can bring in a snow encrusted truck at night and by morning truck and floor are dry as can be. Also very nice when working from a creeper, the heat comes up by you. I've seen some big shops heated by a very small boiler using this system. Just don't do the following--- A new wood chipping plant was built in Western Maine and was designed with in-floor heat. Local contractor did the job and did everything according to blueprint. He completed his portion and came back home. Plant equipment was all fabricated in Quebec and then imported here and installed by the fabricators. Started bolting stuff down and punched three of the zones first day!!!!! Everything stops and big conference ensues!!! Come to find out blueprints were not properly converted to metric for the fabricators!!! Brand new plant, three dead zones. Glad it's not mine. :{ :{ :{

 

[jodog]

THANKS GENE sounds like you have been there,done that!! Big 10 four on the reading part.



As far as drilling holes,I read that you can't even saw cut control joints. Has to be hand jointed at time of placement.

 

[Sled Puller]

If you want, come to the Q&L Rally on April 7, I can show you my system, give you some ideas.

Right AND wrong!!!!

 

[Ben Rumson]

Ditto on the Oxygen Barrier if using the Boiler.



I put a 200k BTU Utica Boiler in our new home and ran baseboard heaters throughout using copper. 4200 sq ft home, 2800 finished. 5 heat zones currently. Will add 2 more when the rest is finished. More zones gives you more felxibility and better heat control.



Side note: We added a second Taco pump to supply hot water to a Bock Turbo-Storr 50 gal. Hot Water Maker ($600). Similar to a hot water heater except it uses your main Boiler for the heat source - kills two birds with one stone so to speak. Very nice. This is very efficient and will last MUCH longer than a standard water heater as long as you keep the anode rod repalced every few years. We have virtually unlimited hot water.



I read up on radiant floor heat prior to doing our baseboards. The difference in these systems is significant - length of zones, different input temperatures, ability to premix with return water to control heat etc. One of my zones is radiant floor under 1000 sq ft of old maple tongue and groove. For this zone we used an aquamixer to lower heat to the 130 degree range (as opposed to 170 degrees) to help prevent the surrounding wood from drying out over time. Floor heat does not need to be (should not be) as hot as baseboard radiators.



Nice system, you'll like it.



I have a source on Utica Boilers in Billings Montana if you're interested - Wholesale/Contractor pricing. I found these to have the heaviest cast iron boiler jacket available for home use. Very nice units. My parents have the same system in No Central Wyoming and love it as well.



Good luck.

 

[jodog]

Thanks for the boiler lead,But I'am still trying to put system together in my head . The primary boiler is going to be gas fired. I would also like to take advantage of some fire wood, but I know this can cause alot of problems with the low temp. needs!of this system.

 

[Ben Rumson]

I forgot to mention that our Utica is gas fired. I didn't find anything that was a combination gas/wood... ?



I would think that you could easily plumb it for either. Then use some shutoff valves on each heat source to designate which source to circulate the water through.



This might necessitate the need for an additional pump ($120) however. You want your pump to be relatively close to the heat source for best efficiency. This being the case, you could have a pump for each heat source and mount it close to the exiting side of each of them. I'd have to pull my data at home to see just how close.



There's alot of tech to doing these systems RIGHT. The Europeans have this stuff down to a science and IMO are much more ahead of the tech on this than we are.



Good luck! READ everything you can get your hands on!!!!

 

[TPCDrafting]

I'm not a heat expert but what about everything else. Is the slab on grade? If so, make sure to put down a min. of 2" rigid insul under the slab. No sense heating the planet, right? Also when I design homes with radiant heat on a structural floor be sure the structure is designed with the added weight in mind. The interior framed walls will need 2-bottom plates because the bottom one will be buried by the gyp/concrete. As well the interior doors need to be set higher to accomodate the slab. If you frame before pouring, the thermal masses won't transfer from room to room thus allowing better control of temps. If you pour, then frame, you'll have to glue down the framed walls to the floor, don't nail!! You're probably aware of this already, just my . 02

Tim

 

[jodog]

THANKS, Tim those are all good points, but I've read that stapeled tubing to the under side of plywood floor is a good way to go!!!

 

[TPCDrafting]

Stapled to the underside of the sub-floor is a good way to go. It leaves your hoses more excessable than putting them in a slab. The downside I've seen is wood doesn't hold nor "radiate" heat as well as concrete or gypcrete. Try putting a rock in your microwave for a while, then try a piece of wood. Remember to put in a glass of water so you don't fry the microwave. See which stays warmer longer after removing. Your system will not have to work as hard if the floor stays warm and continues to heat the house once the boiler kicks off. Also in the heat of summer, you can turn off the boiler and run the pumps to effectively cool the floor making for a cheap way to cool the house. It sounds like you also have a wood burning stove or some other heat source. That is a must with radiant floor heat. It is definatly the "Cadillac" of heat, but the big down side is it takes forever to heat up the house once turned on. Especially if you put carpet over the top of it. Imagine a hot summer going into fall and you get the first cold snap. It could take a full day or more to reach the desired temp in the house. That makes wives and children grumpy!! At least then you'll be able to light a fire or other to help warm the place up. Sorry, don't mean to stand on the 'ol soap box, just my experience in custom home design. Tim

 

[Ben Rumson]

Very good pointers from TCP. He's absolutely correct.



You will need to adjust/get used to how the new system works ie slower warm-ups and cool-downs (response times). Our baseboard heaters provide a very constant even heat with very few if any fluctuation in temperatures. We LOVE it. We are able to "stoke" the temps down for nighttime more effectively than with slab heat. Conversely it takes longer to re-heat the following morning. LIfe is one big trade-off.



A neighbor has the slab heat and can literally lose heat during an extended power outage and still have radiant heat through the night. Thermal mass is, IMO, "exponentially" more efficient than base board and nailed to the underside of plywood.



This said, if you "hang" your pipes to the underside of the joices (like we did under our kitchen and hardwood flooring) you should, at the very least, also consider adding insulation under the pipes to help the heat go up. Yes, heat rises, but you'll need the extra help getting it to transfer through the plywood floor and up into the room above it.



Do NOT finish anything off or add water/antifreeze solution into the system until you've pressured up each loop/zone with air to check for leaks. Note, this isn't a one minute quick check. Pressure the line up and wait at least a day or two to verify NO decrease in pressure over a reasonable time period. For big leaks, you'll know right away. It sucks to come back the next morning and find the guage on zero! But far better at installation than after you've poured around it or put drywall under it for the ceiling of the room below. Take your time here. Double check everything.



Good luck. PM me if you want to double check anything or discuss something.

 

[jodog]

I understand how thermal mass works. But I was told not to expect 2'' of gypcrete to perform like 5'' of regular concrete. I started working the #'s on floor load for light wieght concrete and the clear span of 28' for the 2 car garage under neith It got ugly.

I hope by heating the garage floor an basement floor under the stapled plywood system. I won't notice the low thermal mass of the plywood.

 

[Sled Puller]

I have a 16x30 slab 2 story addition. . The boiler is located downstairs. I was going to pie the second floor, but decide against it.

The downsatirs slab keeps the upsatirs just right with a small $50 electric heater!



I put one 8' foot section of basebord upstairs, (got rid of the electric) and it hardly runs at all.

The concrete and the boiler room keep the upsatirs pretty good.



I keep th garge at 48, and it keeps the bedroom section above at about 65.



It took some tinkering with thermostats, but we finally got it where we wanted, now we never touch them.

Gene

 

[HVAC]

How do you air condition these radiant heated homes? Dehumidify? Ventilate? Filter?

 

[Sled Puller]

AC?

We are from the NE HVAC, 11 months of winter and 30 days of rain.



I would like to do AC, got any ideas?

 

[jodog]

Sled puller, thats good news to me . One reason I want this system is every one knows that the room above the garage is the coldest you owen. And Iam banking on that slab in the garage to make my 28x28 faimly room above cozy.



I have no hands on experience so you're input is verey important to my outcome.



Thanks Everybody





If youre garage is 48* how warm is the slab. I've read that the thermostat should read the slab not the air.



And if I want the slab heat to help upstairs,should I even use insulation in the floor joists?

 

[Sled Puller]

The garage side that is 48 has baseboard heaters in it, I should have clarified.

My feeling on the thermostats is it does not matter where you put them, they will just need adjusted accordingly.

That is not proper, I know, but it works.



We have no insulation in the floors.