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circling the drain
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Discussion Starter #1
Follow up to my anyone know a builder thread.

I'd like to do in floor heating in my next house. We're looking at building a small to medium ranch with a walk out basement (if the stars align, otherwise this could just be random pipe dreams).

I'd like to do in floor heating through out as my primary heat source.

I intend to heat the water with my out door wood burner and pump it through the floors (and hopefully the sidewalks, garage floor and driveway too).

Does anyone have any experience setting up such a system? I've got some ideas, but figure there has to be a better way than I've come up with so far.

Essentially, I'm looking at the same set up I have now. I have the outdoor wood burner set up to heat the water in the home, on a closed loop. Then in another series of closed loops I'd have multiple zones (garage, driveway, basement, living areas, etc).

Where I am struggling is to understand how you control temp/flow to each zone. The simplest solution that I've been able to come up with is to run a thermostat for each zone that will trigger a pump to circulate hot water through that zone as needed.

My concern is allowing a zone to just sit idle, I'm not sure why, but want to make sure that won't cause issues.

Since in floor heating has a lot more surface area than a typical baseboard set up, it appears you can run the water temps much lower. So instead of a boiler to back up the outdoor wood burner, it appears that I can purchase a water heater with teh correct BTU's instead, which seems appealing as it is cheaper than a boiler in some cases.

Anyway, just brainstorming at this point but thought I would see if anyone has a system like this or any experience with it to help educate me in a better direction.
 

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Whoop Whoop
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I've toyed with the idea a few times. I'd be curious about utilizing a tankless setup for the home when it isn't quite cold enough to need to do the garage/driveway.

As long as you are putting glycol in and using pex, shouldn't be an issue. I would maybe consider a single variable output pump with some solenoid valves over multiple pumps, seems like it would be cheaper in the long run.
@FyrFyr might be able to add some since his dad has it in his workshop on multiple zones.
 

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Fucking Zen as Shit
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Yes lower temps than normal radiant heat.
Usually there is a mixing valve that will be preset for the needed temperature (I want to say it's like 104º but i could be way off) that takes the hot water from the boiler and mixes in the needed amount of cold to get it to where it is needed.

You will need/want a thermostat per zone/room. The water will all be connected to a manifold that has the feeds for each zone, with that a thermostatically controlled valve. Since this is a new build and you aren't trying to interface with older technology, the newer systems will have a variable speed circulating motor and motor controller.
The motor controller will sense what is needed and control the motor speed accordingly to save energy.

This is a way better way to go. The house i just bought is baseboard radiator everywhere, but I am adding in Radiant for my office (Freshly enclosed porch with no heat currently) in the floor and then adding underfloor radiant to the master bath since I can easily get to the floor underneath, and possibly my dining, living room and kitchen, since the baseboard radiators are already a touch frustrating with furniture placement.


You need to keep in mind construction. you can embed the radiant tubes in concrete mix or use a system of wood and aluminum transfer plates etc.

You need to think floor coverings, Any carpet or rugs will act like a blanket and just keep the floor warm and not let off the heat to the rest of the room.

In problem areas (stairwells, lots of windows) You can (with proper forethought in utility routing) put the radiant tubes in the walls as well to help get the heat. It's a similar system to the aluminum transfer plates but slightly modified for vertical placement.

I thinks it's the perfect way to go, Like i said, i'm looking at investing in changing a portion of my house out to it. And for my office since it was a porch and I can't easily put it under the floor, i'm going to put it on top of existing floor and raise it 1" (3/4 for the radiant ~1/4" for finished floor)
 

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It is definitely a nice way to heat a house. I did my last house with entirely in floor radiant heat run off a small natural gas boiler. Both the main floor and upstairs were done this way. There were two runs of 1/2" pex-al-pex per joist cavity just spaced down from the floor with 2x4 pieces and attached with cpvc pipe hangers. One pump per thermostat /room/zone with 2 200 ft loops per pump. It worked great and made for a very cozy home.

The easiest and best way to control temp in each room is a theromostat in each room that turns on or off a pump that circulates water in the tubing looped on that rooms floor.

Here is what my set up looked like for pumps and controls.



 

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circling the drain
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Discussion Starter #5
It is definitely a nice way to heat a house. I did my last house with entirely in floor radiant heat run off a small natural gas boiler. Both the main floor and upstairs were done this way. There were two runs of 1/2" pex-al-pex per joist cavity just spaced down from the floor with 2x4 pieces and attached with cpvc pipe hangers. One pump per thermostat /room/zone with 2 200 ft loops per pump. It worked great and made for a very cozy home.

The easiest and best way to control temp in each room is a theromostat in each room that turns on or off a pump that circulates water in the tubing looped on that rooms floor.

Here is what my set up looked like for pumps and controls.



:thumb:

This is what I was envisioning. How much did you have into the whole system ? I know this changes of course with how much pex you need, but was curious on ball park.

Also did you find this to be more economical than a traditional forced air furnace of base board type set up?
 

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circling the drain
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Discussion Starter #6
Yes lower temps than normal radiant heat.
Usually there is a mixing valve that will be preset for the needed temperature (I want to say it's like 104º but i could be way off) that takes the hot water from the boiler and mixes in the needed amount of cold to get it to where it is needed.

You will need/want a thermostat per zone/room. The water will all be connected to a manifold that has the feeds for each zone, with that a thermostatically controlled valve. Since this is a new build and you aren't trying to interface with older technology, the newer systems will have a variable speed circulating motor and motor controller.
The motor controller will sense what is needed and control the motor speed accordingly to save energy.

This is a way better way to go. The house i just bought is baseboard radiator everywhere, but I am adding in Radiant for my office (Freshly enclosed porch with no heat currently) in the floor and then adding underfloor radiant to the master bath since I can easily get to the floor underneath, and possibly my dining, living room and kitchen, since the baseboard radiators are already a touch frustrating with furniture placement.


You need to keep in mind construction. you can embed the radiant tubes in concrete mix or use a system of wood and aluminum transfer plates etc.

You need to think floor coverings, Any carpet or rugs will act like a blanket and just keep the floor warm and not let off the heat to the rest of the room.

In problem areas (stairwells, lots of windows) You can (with proper forethought in utility routing) put the radiant tubes in the walls as well to help get the heat. It's a similar system to the aluminum transfer plates but slightly modified for vertical placement.

I thinks it's the perfect way to go, Like i said, i'm looking at investing in changing a portion of my house out to it. And for my office since it was a porch and I can't easily put it under the floor, i'm going to put it on top of existing floor and raise it 1" (3/4 for the radiant ~1/4" for finished floor)
Looking at 1 floor ranch with walk out, so I won't be too concerned with heating any stair cases. No carpet in the house, we'll be going with hard wood, tile, and then the basement will just be concrete for now, may carpet it later, or could so something like tile or wood to help the heat pass through, but figure it should still allow enough heat through to keep that room warm enough if I did carpet.

I need to look more into these valve set ups. Simplicity and cost are both of the essence.
 

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Whoop Whoop
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My dad has a 1700 sq ft burm ranch on a slab (no basement). It is 2x6 walls, with concrete up to the burm level, has insulation outside of the cement walls. Burm is around approximately 60%. burm is about 3' up the wall.

He pays less than 130 a month in the winter and summer for natural gas and electricity, and keeps his home around 72 in winter/68 in summer.

Something else to ponder on.
 

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Resident HVAC/R Jambi
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If you don't run your water temps over 130* you don't need to use mixing valves. If you want a back up boiler and don't want mixing valves you will need a condensing boiler. If you are building new then do the basement right and floor heat that as well.

Otherwise, you're on the right track.
 

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Have installed many,and helped many more,just let friends new build(4500 sq.ft)walk out,and a 60x100 hot rod garage.all done with infloor,also doing snow melt,the house will have a forced air system for a/c.and heat back up(98%eff).thesky is the limit,building in serviceability cost more up front,but pays back over time,(shut off vales before and after everything).if you use the same pump for all zones ,haveing one spare the same is easy,some try. To scale down pumps,(variable pumps are mt choice).the biggest difference I see is how. Well(or lack of)they insulate),6"walls,min of 4"foam under slab.vapor barrier,etc,pay now or pay later.......propane or nat.gas also comes in to play,we only do glycol systems,not all tankless or boiler company's will warranty a system withglycol in it!!!.
 

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Eye candy
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More effort and cost than it's worth is my guess. Yet I'm the strange one :p
 

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Good advice above. My dad's set up is similar. He does use a gas water heater for the primary. Insulation before the cement is key.


Sent from my iPhone using Tapatalk
 

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I'll Direc your TV
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More effort and cost than it's worth is my guess. Yet I'm the strange one :p
He's building a new home, wants to do it so he doesn't want to go "damn should have done that when I built the place", and I can't see it costing more than it would be worth.

You wouldn't want a nice heated floor when it's 5 degrees outside?

Never mind, you probably wouldn't
 

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Insutate,insulate.buy the best equip u can afford,and never look back, oh and how it's installed is important also.quality equip,installed poorly is not money well spent.
 

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do some research on glycol. it will break down and degrade over time without proper treatment, additives when used at higher temps in boilers. just plan on checking condition of it annually especially if you have a high efficient condensing boiler where water treatment is critical.
 

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We use glycol that is formulated for boiler use(has additives).pluse closed system,have not seen any problems ,even in 15yr old systems,
 

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I'm not old, honest...
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He's building a new home, wants to do it so he doesn't want to go "damn should have done that when I built the place", and I can't see it costing more than it would be worth.

You wouldn't want a nice heated floor when it's 5 degrees outside?

Never mind, you probably wouldn't
If he plans to stay in the new home for a long time, I agree. If it's a short term stay where he won't see the payback, then not so much.
 

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skillicous
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Follow up to my anyone know a builder thread.

I'd like to do in floor heating in my next house. We're looking at building a small to medium ranch with a walk out basement (if the stars align, otherwise this could just be random pipe dreams).
You really need to just come see our place. We have a ranch with walkout. The basement has in floor heat through the whole place, the living floor is heated via forced air when needed (not needed above 40F or so). The forced air has a heat exchanger that is fed my our wood burner. We also heat the hot water with the wood burner. The barn also has in floor heat.

We chose not to do any in floor heat right under the first floor. We wanted a forced air system for AC (and for resale) so adding a heat exchanger for the wood burner into that was must cheaper than doing in floor under the first floor.

If I keep the basement at 70, the upstairs stays at 70 until the external temps drop below 40. Colder than that and the forced air turns on to help heat the place.

Another thing to consider is if your new place would have propane or NG. Obviously that changes the numbers in terms of ROI. We're on propane, so the investment was a no-brainer. We havent used propane to heat the place since the boiler was all hooked up in October.

More effort and cost than it's worth is my guess. Yet I'm the strange one :p
and you came to this conclusion how?
 

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circling the drain
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Discussion Starter #19
You really need to just come see our place. We have a ranch with walkout. The basement has in floor heat through the whole place, the living floor is heated via forced air when needed (not needed above 40F or so). The forced air has a heat exchanger that is fed my our wood burner. We also heat the hot water with the wood burner. The barn also has in floor heat.

We chose not to do any in floor heat right under the first floor. We wanted a forced air system for AC (and for resale) so adding a heat exchanger for the wood burner into that was must cheaper than doing in floor under the first floor. So you basically went the route of forced air heat, supplemented with in floor in the basement powered by the boiler for both. I like the feel of radiant heat (like a wood stove, in floor, etc.) I kinda hate the ups and downs of forced air, the drafts, etc. Which is why I was leaning more towards just floor heating, powered by the boiler, with proper back up (ng or propane heater/boiler) for resale concerns.


If I keep the basement at 70, the upstairs stays at 70 until the external temps drop below 40. Colder than that and the forced air turns on to help heat the place.

Another thing to consider is if your new place would have propane or NG. Obviously that changes the numbers in terms of ROI. We're on propane, so the investment was a no-brainer. We havent used propane to heat the place since the boiler was all hooked up in October.



and you came to this conclusion how?
Will have to come check it out, been a while since we've made it down there....like you were still in the air stream :teehee:

Not certain I want the forced air, but it does solve the AC equation.

Haven't found a lot yet (or finished getting my current house ready to sell), so no idea whether we'll be on NG or propane.
 

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skillicous
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Not certain I want the forced air, but it does solve the AC equation.
the issue you are going to find is that almost all counties wont allow wood as a primary heat source since it has to be "maintained". You are required to have a primary heat source that doesn't require someone to be there shoveling wood in, which is actually a good policy. The reasoning is if you have a medical issue or go on vacation in the winter, etc, the house can still be heated. That means you are either going to be putting money into electrical baseboard heaters or a forced air system. Combine that with the higher resale value of having AC, it was a fairly simple decision of where to put the money.

So the NG/propane "back-up" system actually has to be sized to be considered a primary. I'm not sure what the cost of that would be, allong with the controls to automatically fire up when your main boiler drops below a limit switch.

In either case, forced air heat with AC is really where its at for resale...
 
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