空气供应管道是否在绝缘墙上存在潜在的水分问题？
These are warm air supply ducts (3.25 x 10) in a 2×4 wall with just 3.5″ fg batt insulation. The ducts are against the interior face of the exterior board sheathing. This house has not been occupied in the winters (coastal maine) but is being renovated to be year-round. Prior to demolition we had planned to foam the wall cavities where interior finishes were stripped but did not know the walls were only 2×4. Will warm air traveling thru these ducts condense its moisture on the inside of the duct or cause condensation at the sheathing plane? In the dead of winter, will that air even be very wamr when it gets to the second floor?
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答复
托德，
It sounds like you have forced-air supply ducts in your exterior walls. That is never a good idea.
主要原因这是一个坏主意的是能量浪费。在冬季，这些管道非常热，你的螺柱海湾很冷。
If you ever install air conditioning, that's when you have to worry about condensation and mold. During the summer, the ducts will be cold, and any humid exterior air leaking into the wall cavity will contribute to condensation.
The solution is to remove all ducts from exterior walls, and fill the stud bays entirely with insulation. Relocate the ducts to new chases that are framed on the inside of your house. And be sure that your chases are air-sealed, and your duct seams are also sealed.
托德，what is the heating fuel and appliance you are using? Any chance you can get rid of ducts entirely and switch to a ductless heat pump? Or, if you're going to continue with ducts, get them entirely inside the house? That means no exterior wall stacks, nothing in an unheated attic, etc.
感谢信息Martin和David，我很乐意去除导管，但预算可能会阻止它发生。所以，在冬季的冷凝下，在该导管的内部不会形成，因为空气太大了？
大卫，炉实际上只有大约2岁，而且被炸油，因此所有者对系统进行了重大变化。他们肯定在马之前在车上之前。如果我们能找到空间以容纳一切，我可能能够让它们移动导管。
即使在接缝密封后，管道也不能完全密封。在炎热和冷空气之间存在温差的情况下，凝结将很可能发生。
Ducts on the outside wall is a very bad idea.
托德，you said: "The ducts are against the interior face of the exterior board sheathing." Whether there could be any condensation within the duct in winter depends somewhat in the ductwork configuration. Here is a scenario I envision. Say there is a return register somewhere in the house and not feeding another duct inside the exterior wall, so that the "warm" air comes up through the supply ducts into the rooms, then returns to the furnace via the rooms themselves. When the heating system is not running, there could be reverse convective looping, with room air settling down through the registers, passed the blower and furnace and into the rooms again. The air inside the house, dry as it may be in winter, almost certainly will be humid enough so that some condensation could conceivably occur at that cold outer duct surface next to the sheathing. Of course, if there are motorized dampers, as there would be with a zoned system, then the convective flow wouldn't occur. Edit: Actually, at least some systems involving motorized dampers leave all the zones open when the blower is not running, then close all but ones calling for heat when the blower runs. In that case, perhaps some reverse convective looping could occur.
Even so, the others are right, you need to get the ductwork out of the exterior walls. The savings in heat cost will pay for the relocation in short order.
托德，you can add depth to the wall at duct locations or whole sections of the walls. Then move ducts inward and add ridged foam behind. Thousands of homes haves similar ducting. No it is not the best idea but all building are full of best compromises.
Some of the above posts are not understanding your need to work within a budget and the needs you have.
我喜欢'AJ Builder，Upstate Ny区6a'答案，但我留下了一个框架的壳，带有2x6墙壁的外墙，连接到2x10大教堂天花板托梁作为我的回归渠道，我该怎么办？请帮忙！
Chris Jeffers,
You should build a chase.