Clothes Dryer Makeup Air - A Better Way?

[Hube]

That would appear better than a straight pipe but there are issues. If you house is not very tight there will be drafts through this pipe. You have now provided a low resistance link to the outside. It will increase overall infiltration.

Why you run any exhaust fans air will be drawn in through the pipe.
End of quotes.
**********************************************
Alternety;
if the house is not very tight then no combustion air is ever required as it is already there because the house is not very tight.

In a tight house there will be NO drafts as this anti -spill type will allow air only to come in as it is required by any of the exhausting appliances.

Note that the poster (sixlashes) said his house was VERY TIGHT.

 

[Alternety]

This is an older post and I did not go back and read the whole thing. If the house is tight, the only source of draft is if there are any exhaust/exchange systems that are not balanced with their own makeup air.

In my own environment I have only three controlled points of interaction with outside air. A heat recovery air exchange system, the range hood with its' own powered make-up air system, and the dryer. And a couple of doors that really don't seal as well as they should. I also have an issue with certain drain systems within the house that were built, in contradiction with plans and instructions, without traps. Plumber either thought I was crazy (not an isolated view among the builders) or just did not want to work that hard. I am working on these entry points, but retrofit is tricky.

It is hard to balance, and keep balanced, external air exchange systems. In all likelihood there will be some interaction with this laundry vent if it is not actively managed (i.e., closed when not in use).

I am a real fan of tight houses. I have about 6,000 sq ft and I use about 800 gallons of propane for heat, hot water, and cooking in a year in the PNW. And that is with stupid walls. I designed for SIPs. Engineer had no idea what they were. Wound up doing studs with spray foam. Each stud is a heat leak so I will not equal a SIP for heat loss, but I am airtight. I did not put on an external sheet of foam board because of fire issues and depth of wall vs already ordered windows and doors. I live in a forest. Since this is my last house, this annoys me very very very much.