Ok so bear with me I’m new to radiant floor heat. So we just finish building a new house. I ran my floor loops. Just purchased a new crown royal multi pass owb. I’m working on getting everything hooked up. So my thought was you could just run your line from the stove to a manifold, through the floor and back to the stove. After reading some things on here I realize that is not the correct method. Looking for help on setting up the best system. The stove is a duel pump set up. One line will go to the furnace in my shop, which I have set up before. Thanks in advance.
New to radiant floor heat
- Thread starter brentchaffin
- Start date
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Gearhead660
Minister of Fire
What is your back up heat source? Gas fired boiler? Common practice is to use a heat exchanger to keep boiler water and home water separate.
so backup heat would be an electric furnace. I’m hoping with the floor heat it won’t run much. So the heat exchanger would use the boiler water to heat the floor water without mixing. So is a mixing valve still required to reduce the temp of the water going into the floor?
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I don't see any reason that you couldn't run boiler water through the floor. Mixing valve somewhere to keep temperatures low enough for the concrete.
So my understanding is a heat exchanger will send the correct temp water into the floor system. So I guess no mixing valve is needed with a heat exchanger? How does one determine the btu needed for the correct size exchanger?
Bad LP
Minister of Fire
a heat ex changer will not regulate the temperatures.
You should still have a a way regulate your water temp going to the concret floor
You should still have a a way regulate your water temp going to the concret floor
So The heat exchanger says it would be 120° water at radiant side. Then if I put a mix valve in after the heat exchanger I should be able to regulate 100° water going into the floor.
The heat exchanger temps will fluctuate depending on flow rates and boiler temp, that's why you need a mixing valve to control the water temp going in the slab.
I personally don't use a heat exchanger to separate the boiler water and floor, but we are farther south so freezing a floor is rare, and our furnaces are all stainless so less chance of sludge in the floor loops.
I personally don't use a heat exchanger to separate the boiler water and floor, but we are farther south so freezing a floor is rare, and our furnaces are all stainless so less chance of sludge in the floor loops.
Thank you. I forgot the pump in the manifold side. Also thought about adding a bypass line to fill the floor loops from the lines from the stove. Something like this:
Your floor system will have its own expansion tank, air bleed, and pressure. The boiler side might be glycol, no pressure, and funky. I don’t think you want to try and connect the two with a bypass. May as well just skip the heat exchanger then.
I don’t have any water plumbed to the floor system now. Just trying to figure out where to pull water from. I also don’t have an expansion tank or air bleeder in the system. I had thought I probably need an air bleeder. How vital is an expansion tank?
maple1
Minister of Fire
Could just plumb a couple hose bibs in, in proper spots, for filling with a garden hose. Should also plumb some in along with isolation valves for easy HX flushing/cleaning on the boiler side of it.
Got the stove mocked up today.
Here is the plan for plumbing at the manifold. What do you think? Any thing I need to add/remove?
Bad LP
Minister of Fire
You need an expansion tank. I'd flip the two ball/drain valves and add a drain to the cold side.
Ok minus a few fittings this is my layout. Water in from the right and manifold on the left. What do you guys think?
Ok so got my system all setup. Still trying to fine tune it. Seems I’m getting less then 1/2 a gallon/minute of flow through each line. Trying to work out how to increase flow. Running an 007 taco pump. Will a bigger pump with more head flow help? Maybe split it up and run 2 pumps, 1 per 3 loops? Any suggestions?
Maybe open those closed ball valves on the loops? Why did you use those ball valves in addition to the valves on the manifolds?
I see you used pex . Did you use the heating barrier pex or regular water pex?
Do the manifolds have pressure gauges too?
The valves are just closed in the picture. When I run them all open flow rate is very slow.
I used the ball valves so I could shut down loops if needed. An oversight since I can shut them off at the manifold but they are there now.
It is heating barrier pex.
The manifolds do have gauges. It running like 3 kg/cm2
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