3 ms·
It's not supposed to be sealed, it's just supposed to have draft. (the flue always vacumming from convection)
by Brian_K_White 4y ago
It's not supposed to be sealed, it's just supposed to have draft. (the flue always vacumming from convection)
- throw0101c 4y ago> It's not supposed to be sealed, it's just supposed to have draft. It depends on the model. High (>90%) efficiency, condensing furnaces are completely sealed off from the house: they take in air from the outside (via PVC pipe), combust, extract the heat, and exhaust the results (via PVC pipes). * https://www.youtube.com/watch?v=lBVvnDfW2Xo https://www.youtube.com/watch?v=lBVvnDfW2Xo Older lower efficiency (<85-90%) furnaces suck in air from the house, exhaust into metal pipes (PVC would melt because not as much heat is extracted from the fumes), can be back-drafted and you have to worry about CO. Basically: if the furnace has vents in which you can see a pilot light, it's the older style.