hvacpvcvent
There is a large PVC pipe (3 actually) which vent air intermittently. I started noticing I could see steam rising over my deck in the morning and then I found that these pipes vent air at least a couple times per hour.
What is the purpose of this venting? I'm concerned about efficiency.
Bonus: When the pipes are venting it is fairly noisy. When we're on our deck we can hear it and it's annoying. Any way to muffle this noise without impacting the operation?
PVC does not need to be buried, however the advantages are:
As for pipe size, it depends on the size of hose spigot you use. It will most likely be 1/2" or 3/4" (some come with both sizes). When dealing with different materials, use the same nominal pipe size (3/4" copper = 3/4" PVC).
Personally, I would look at using PEX pipe and bury where possible. The exposed pipe will be less susceptible to breakage than PVC. Also due to its flexibility, you can run it without the need for additional fittings. If you don't have PEX crimpers, you can use Sharkbite push-on fittings (the same fittings can be used to transition from copper to PEX).
That pipe looks like an air intake.
All "direct vent" style appliances (high efficiency on-demand water heater, gas fireplace, etc.) have an isolated air intake and it is common to have it suck in air from outside the building so as not to force air infiltration through doors, windows, etc.
Indeed, that is ugly. Our fireplace and tankless water heater have something far more elegant:
The stack on the left is a natural gas tankless water heater. The right is a direct vent natural gas fireplace insert.
Best Answer
Do you have a high efficiency furnace? If so this is the exaust and air intake for your furnace. Unlike older furnaces, HE furnaces do not exaust up through your chimney and instead use PVC or ABS pipes.
Not sure about the third pipe though - do you have a heat exchanger?
Best way to know for sure what they are is to try and trace them back to the source.