INSULATING A BASEMENT KNEE WALL IN WINTER

[Brimfield]

I have a walk out basement with a knee wall along the front . I can feel the cold air coming in. The construction is 2-4 framing with T 111 exterior, the inside has r 13 kraft faced insulation with 2" of foam insulation board with the rest of the basement with 1" foam board on the walls. Air is still coming in and cooling the basement down. I have an outdoor wood boiler and the water comes in the house around 180* and cools down to 172 at the heat exchanger. The water then goes into the indoor boiler system at 162 and comes back at 150*. The pex pipe runs the length of the basement, 30 feet. The heat off the pex lines used to make the basement the warmest place in the house. The rest of the house is well insulated with newer windows. Now in 15* days and 2* nights the heat can't get above 60* and that's with the circulator pump running 24/7.

I want to spray foam insulation in all the knee walls but it is too cold for that. Any other thoughts for now? I hate to tear down the insulation board that's there now but I may have no choice. Any thoughts on getting a kit to spray it on my own or is it just as well to hire it out. I used to work with 2 part spray insulation, I know the part a stuff is a mess and that it needs to have the tanks at or above 70* to spray well.

 

[nybirdman]

My son has had an outdoor boiler for about 8 years;so I have a little
experience+ being a pipefitter/steamfitter for 40 years.
First thing I would do is turn up your outside boiler to 190-195 degrees.
His was piped direct to his inside boiler;it never heated the house right.
The fix was to move the inside circulator(first floor) from the return to the
supply.His system was always getting air bound;works great now.

 

[RNeumann]

I’m lost with regards to the question. It sounds like the basement used to be the warmest place in the house and now it isn’t? If that’s the case why do you want to rebuild/redesign walls? It sounds like you need to fix the heating system?!?
If that’s the case I’d start with the basics of a boiler system- air in the system?, pump gone bad? Etc.

 

[Brimfield]

My son has had an outdoor boiler for about 8 years;so I have a little
experience+ being a pipefitter/steamfitter for 40 years.
First thing I would do is turn up your outside boiler to 190-195 degrees.
His was piped direct to his inside boiler;it never heated the house right.
The fix was to move the inside circulator(first floor) from the return to the
supply.His system was always getting air bound;works great now.

Yea I had the same problem trying to use the pump at the outdoor boiler to circulate the whole house. I had lots of air in the zones if the OWB shut down for a fire out and the thermostat shut off the flow. So I put a heat exchanger in just before my gas boiler and kept the 2 systems separate. Before that I was fighting a 10' climb from the boiler to the basement and then 2 more stories to try to circulate the hot water from the OWB and always got air lock if the boiler went out.

I’m lost with regards to the question. It sounds like the basement used to be the warmest place in the house and now it isn’t? If that’s the case why do you want to rebuild/redesign walls? It sounds like you need to fix the heating system?!?
If that’s the case I’d start with the basics of a boiler system- air in the system?, pump gone bad? Etc.

The basement was the warmest room in the house, The OWB pump keeps a 24/7 from of hot water into the exchanger before the house system. The pump is fine with no air in the system so the basement was warm but this cold weather has lots of air leaks from the knee wall. I know the tanks for spraying insulation need to be around 70*+ but thats hard to get this time of year.

 

[nybirdman]

On my son's unit;there is no heat exchanger;the outside boiler just fed the house boiler.That's the way it was installed by the contractor/seller.Didn't work well until we moved the inside pump to the supply.
I still would up your outside boiler to at least 190*F.

 

[Brimfield]

On my son's unit;there is no heat exchanger;the outside boiler just fed the house boiler.That's the way it was installed by the contractor/seller.Didn't work well until we moved the inside pump to the supply.
I still would up your outside boiler to at least 190*F.

I actually raised it to 190 and it helped some. I had my house boiler circuit running off the outdoor boiler circulator but the upstairs would get air bound after time and if the fire died forget it. But the heat is up to 62* and my wife can deal with that until I fix the walkout basement.

 

[ktm250rider]

Find and seal the air leaks. You cant raise the temp high enough to heat the outside. I built my house 10 years ago and i still hunt them down. Pics would help. Does the knee wall have a rigid thermal break? Batt insulation will allow air flow. If the 2" foam covers the hole wall, make sure all seems are sealed.
Your temps look similar to mine and i run at 180.

 

[sailfast]

I have a walk out basement with a knee wall along the front . I can feel the cold air coming in. The construction is 2-4 framing with T 111 exterior, the inside has r 13 kraft faced insulation with 2" of foam insulation board with the rest of the basement with 1" foam board on the walls. Air is still coming in and cooling the basement down. I have an outdoor wood boiler and the water comes in the house around 180* and cools down to 172 at the heat exchanger. The water then goes into the indoor boiler system at 162 and comes back at 150*. The pex pipe runs the length of the basement, 30 feet. The heat off the pex lines used to make the basement the warmest place in the house. The rest of the house is well insulated with newer windows. Now in 15* days and 2* nights the heat can't get above 60* and that's with the circulator pump running 24/7.

I want to spray foam insulation in all the knee walls but it is too cold for that. Any other thoughts for now? I hate to tear down the insulation board that's there now but I may have no choice. Any thoughts on getting a kit to spray it on my own or is it just as well to hire it out. I used to work with 2 part spray insulation, I know the part a stuff is a mess and that it needs to have the tanks at or above 70* to spray well.

How cold is it? We can apply spray foam at pretty low temperatures. Hard to believe it is too cold. Might need to turn up your house heat a bit but if it is inside your house it should be good. A trick is to build up a certain thickness to each lift so the heat of the foam reaction feeds the next lift.

 

[nybirdman]

I actually raised it to 190 and it helped some. I had my house boiler circuit running off the outdoor boiler circulator but the upstairs would get air bound after time and if the fire died forget it. But the heat is up to 62* and my wife can deal with that until I fix the walkout basement.

You cannot use the outside boiler circulator to circulate in the house;for one you have no control.The inside pump is turned on/off by the thermoset.
Most inside boilers have the circulators on the return side of the boiler;this does not work when you have an outside(open to the atmosphere) boiler connected.
You must move your INSIDE PUMP to the supply so it "pushes" not "pulls.
As far your drafts;I would put up a plastic barrier until the weather warms.

 

[aczlan]

I would find the air leaks first (if you dont have one, get an IR thermometer such as Amazon.com: Etekcity Lasergrip 774 Non-contact Digital Laser Infrared Thermometer Temperature Gun -58℉~ 716℉ (-5℃ ~ 38℃), Yellow and Black: Instant Read Thermometers: Kitchen & Dining ), that should slow the loss down a little.
Then I would order a sprayfoam kit and when you have a warm day predicted pull the existing insulation off, then spray the wall. To help a little more, I might run an additional heater (perhaps a kerosene or large electric heater, several medium electric heaters or talk to your local rental yard about renting one of their heaters) in that room to get it hot. Yes, it will cost more for fuel, but it will help the foam expand (you might even set the tanks in a tub of hot water to make sure the raw components are warm enough).

Aaron Z