Using attic heat to warm up basement

[Xringer]

The goal of this project it to pump solar warmed air from the attic, down to the unheated basement.
For two reasons:
I want to be able to work in the basement when during the winter.
(When it's 60-65F down there).
And, I want to provide a little warm air for the A7 Airtap (DHW ASHP).

I have an exhaust blower already installed in the basement.
The air intake is 10" off the basement floor. It's suppose to pump the cold air into the outdoors.



My CAI controller is using temperature and RH as inputs and X10 for control.
I've had success in using this fan during this summer, pumping out
the cool damp air, while the outdoors RH and temp are within acceptable ranges.



This new 200 cfm fan (coming next week) will be installed in the attic.
It will also be controlled by X10.

4" inch 200 CFM Inline Fan Duct Booster Exhaust Vent Blower Hydroponic Radon M 4 | eBay

I plan to use this 4" dryer duct hardware for the attic install.

The tubes are 8' x 4" and should fit the Tjernlund M4 blower.


The dryer exhaust port will be mounted on the ceiling of the small back hall
(or landing) that connects the basement stairs to the kitchen and back entry door.
This 'hall' is where the pull-down attic stairs is located, so the install shouldn't be too hard.

Using the outdoor RH reading and attic temperature (and time of day),
the CAI controller will turn on both blowers when the RH is low
and the sun has heated up the attic.
I'll post the control program after I get it debugged.

I've been thinking of a method of closing the plastic flap inside the dryer exhaust port.
It would be nice to keep warm air from floating up into the attic during the night.
Some fishing line with one end weighted, thru the flap, connected to a hook on a roof rafter.
The light weight will pull the flap up, and it will be easy for the air flow to push down (open).