DIY ventilation heat exchanger

poorwill · 06-19-21, 12:41 PM

I have sealed our house to about 2 air exchanges per hours at 50 Pa. I fear some of the bedrooms are even tighter with their doors shut. Making a heat recovery ventilator may be the solution or just blowing a little fresh air in each of the bedrooms may be enough. Where I live, the Connecticut coast, a recuperator would achieve very little in the spring-summer-fall. Running the fresh fan at night and not during the day may be enough. In the middle of the winter, the stale air inlet could be from the ceiling above the wood stove as well as the bathrooms.

I have looked at the difference between aluminum verses plastic as an exchanger material. The efficiency seems dominated by the film coefficient and not the material conductivity. Plastic may be weaken by ice but I have not confirmed this. Plastic (coroplast) appears cheaper than aluminum flashing. Icing could be controlled by timing the fans and/or a bypass valve on the fresh air side.

The first step is to make an fresh air distribution manifold to the bedrooms. The bathrooms are already plumbed through a single Fantech FR100 to the outside. I purchased another Fantech FR100 for the fresh air side. I will connect this fan to a filter -- check valve -- outside. I will instrument and control this with Auduino. I hope then the final steps will become obvious.

I will try to post updates. Please advise at any point along the journey.

06-19-21, 12:41 PM	#22
poorwill Lurking Renovator Join Date: Jun 2021 Location: Connecticut Posts: 3 Thanks: 5 Thanked 1 Time in 1 Post	Aluminum verses plastic I have sealed our house to about 2 air exchanges per hours at 50 Pa. I fear some of the bedrooms are even tighter with their doors shut. Making a heat recovery ventilator may be the solution or just blowing a little fresh air in each of the bedrooms may be enough. Where I live, the Connecticut coast, a recuperator would achieve very little in the spring-summer-fall. Running the fresh fan at night and not during the day may be enough. In the middle of the winter, the stale air inlet could be from the ceiling above the wood stove as well as the bathrooms. I have looked at the difference between aluminum verses plastic as an exchanger material. The efficiency seems dominated by the film coefficient and not the material conductivity. Plastic may be weaken by ice but I have not confirmed this. Plastic (coroplast) appears cheaper than aluminum flashing. Icing could be controlled by timing the fans and/or a bypass valve on the fresh air side. The first step is to make an fresh air distribution manifold to the bedrooms. The bathrooms are already plumbed through a single Fantech FR100 to the outside. I purchased another Fantech FR100 for the fresh air side. I will connect this fan to a filter -- check valve -- outside. I will instrument and control this with Auduino. I hope then the final steps will become obvious. I will try to post updates. Please advise at any point along the journey.