Radiant heating is cold temps

[JECulver]

This is my first winter with radiant heat and I have a question about the temperature setting of my water. I am presently running 115 boiler temp and my return temps are 95. We are headed into a very cold stretch which it will be close to -40. Should I increase my water temp to compensate for these extremes?
I have a 3200SF Barndominium Half house set at 72 and half shop set at 60 2" of spray foam over the entire shell. I designed and installed the system myself and an very pleased with the performance so far. I am retired and doing all the interior work myself and hope to finish the inside this summer.
Thanjks for the reply

 

[jack stand]

I think knowing what you're boiler is would help. I heat my radiant with a wood gasification boiler. It holds about 60 gallons of water.
You're 115* boiler temp, is that the cut off setting, or are you mixing it down from a higher temp with return water/mixing valve.
Either way I think you're questioning is on target with -40* coming. I'm no expert but from my experience, higher water Temps or storage would be beneficial.

 

[TurnipTruck]

115*F going into the concrete floor is just right. What is the temperature of the water leaving the boiler? How are you mixing? Pics of boiler and surroundings?

 

[JECulver]

It is a Combi boiler, closed loop and my set point is 115. the system holds about 38 gallons total. six loops on three zones for the house and one zone 5 loops for the shop. Here is a picture of my system. It is not completly done but is working

 

[JECulver]

Boiler temp is 115. Going into the concrete it's 111. Return is 92 and outside temp is -10 right now. Still 72 inside

 

[TurnipTruck]

I presume the blue thing is a flow sensor for the variable speed loop pump? I would not have thought one single pump could do a building that size!

 

[JECulver]

Pump flow max's out at 8GPM Might be undersized . Main zone of the house is 4 loops and typically flows 4 gpm when that is all thats calling for heat

 

[jblnut]

I wouldn’t raise temp’s unless you need to. I don’t touch my supply temps all winter and run 95f water through the floor. No issues even when it’s -25f and windy. I have an outdoor boiler supplying the shop and house so longer heat cycles with higher return temps is the goal. When I run the LP boilers I have them set to 120f and don’t touch them all winter.

 

[Two Pump Chump]

Two inches of foam insulation ? How does that meet code in an area where it can get -40. I thought R49 ceiling was the standard, and that's 7-inches minimum. Walls now R22 which is also more than 2 inches of foam. Also, why are you using water instead of coolant ? Good luck, it sounds like your system is working perfectly.

 

[JECulver]

No building codes where I live except electrical and septic. I am using coolant in my system. Exterior walls will have R15 mineral wool added when everything is finished. Ceiling will have sound insulation when completes as well. Temps hit -37 and house dropped to 70 overnight but rose once we were up and the sun came out. plan on installing a pellet stove in the future as a backup.

 

[PoorUB]

Run the water temp as low as you can and still reasonably heat the building. If 100F will heat it, then that is a good temp.

 

[Firebrick43]

Many of the aquabalance boiler you can add an optional outside temp sensor and the boiler (depending on its program) will automatically adjust its temp to compensate for severe cold weather.