In an effort to make this topic more searchable and to not hijack maple1’s thread I am posting this topic on panel radiators separately.
Heaterman: What brand of panel rad does your son have? I have not yet installed an under-floor, between the joists, hydronic heating system under the hardwood living room floor to replace and/or offset the forced air supply to this room. Panel rads sure look good if you can get heat at 110*, especially with my Garn. I have looked at some information but it seems they are more designed for 140* and up. Are there charts for BTU’s/ft at temperature X? Sawyer
You can find all you need to know here. http://www.hydronicalternatives.com or more specifically > (broken link removed to http://www.hydronicalternatives.com/html/radiators.html)
That page will have everything from installation to temperature correction factors. As a rough rule of thumb, I add about 30% capacity for reduced temp operation. In other words if I have a room that requires 6,000btu I will select a rad rated for 7,500-8,000 at normal temps.
If you really want to get scooby doo about it, install a motorized mixing valve that provides outdoor reset of the water temp in front of your panel rad manifold. I love the feel of a 100* rad on a cool April or October morning. Signature Heaterman Saving the world, one wood boiler at a time.
Heaterman: Just a clarification on your 30% upsize rule of thumb for low temp use of radiators…..... After looking at the correction factors for low temp hydronics @ Hydronic Alternatives….... Assuming I ran my (green submarine) storage down to say…120 degrees…...and assumed a 10 degree delta thru a heat exchanger…...this would give me a supply temp of 110 degrees to the radiator…..if I plug in a 68 degree room temp - the table gives me a correction factor of 4.2 (assuming a 100 degree return temp).......which I think says that to get 5k btu I would need to find an emitter with 4.2x5k = 21k btu rated output at their standard conditions to pull 5k btu from it…... are you saying that in the “real world†1.3 x 5k btu = 6500 btu is workable?..... I’m trying to rough out some budget numbers for emitters and see a 3x spread from what I thought I needed to budget…... just a silly survey guy dabbling in heat stuff…..which is always a bit scarey…. Is there maybe enough thermal mass in a building to make just a 30% upsize work thru a short period of low temp supply that is common with the storage approach?
Eauzone Dan
Heaterman: What brand of panel rad does your son have? I have not yet installed an under-floor, between the joists, hydronic heating system under the hardwood living room floor to replace and/or offset the forced air supply to this room. Panel rads sure look good if you can get heat at 110*, especially with my Garn. I have looked at some information but it seems they are more designed for 140* and up. Are there charts for BTU’s/ft at temperature X? Sawyer
You can find all you need to know here. http://www.hydronicalternatives.com or more specifically > (broken link removed to http://www.hydronicalternatives.com/html/radiators.html)
That page will have everything from installation to temperature correction factors. As a rough rule of thumb, I add about 30% capacity for reduced temp operation. In other words if I have a room that requires 6,000btu I will select a rad rated for 7,500-8,000 at normal temps.
If you really want to get scooby doo about it, install a motorized mixing valve that provides outdoor reset of the water temp in front of your panel rad manifold. I love the feel of a 100* rad on a cool April or October morning. Signature Heaterman Saving the world, one wood boiler at a time.
Heaterman: Just a clarification on your 30% upsize rule of thumb for low temp use of radiators…..... After looking at the correction factors for low temp hydronics @ Hydronic Alternatives….... Assuming I ran my (green submarine) storage down to say…120 degrees…...and assumed a 10 degree delta thru a heat exchanger…...this would give me a supply temp of 110 degrees to the radiator…..if I plug in a 68 degree room temp - the table gives me a correction factor of 4.2 (assuming a 100 degree return temp).......which I think says that to get 5k btu I would need to find an emitter with 4.2x5k = 21k btu rated output at their standard conditions to pull 5k btu from it…... are you saying that in the “real world†1.3 x 5k btu = 6500 btu is workable?..... I’m trying to rough out some budget numbers for emitters and see a 3x spread from what I thought I needed to budget…... just a silly survey guy dabbling in heat stuff…..which is always a bit scarey…. Is there maybe enough thermal mass in a building to make just a 30% upsize work thru a short period of low temp supply that is common with the storage approach?
Eauzone Dan
