The average daily max in September (month 9) is 78.5. This might be another
ventilation month, or an air conditioning month, if it's warmer than average,
or a dehumidification month, if it's cooler.

month outdoor min slab nat slab
temp (F) temp (F) temp (F)

9 68.5 73.23895 56.5

We might automatically change a $69 window AC from AC to dehumidification and
back by adding a box around the outside with a $50 2 W (Honeywell 6161B1000)
motorized damper with a hinge h at the top that opens for AC and closes for
dehumidification, with horizontal partitions p and one-way passive plastic
film dampers Di and Do on each side of the AC in the window mount flanges.
It might look like this in the AC damper position, viewed in a fixed font:

--------
ceiling |
|
| window
|
|
---|---------------------h---damper--- (AC)
| |. | .
| |.Do f c| .
| |. a o| = .
| | n n| .
| | d| .
| |--------p------|--p--.
| .| condenser | .
| Di.| inlet air | = .
| .| | .
------------------------- (dehum)
|
|
|
floor |
--------------

The exterior damper would close and the passive interior dampers would open
in the dehum (heat pump) position, as the condenser fan makes in-house air
pressure and flow above and out-house suction and flow below:

--------
ceiling |
|
| window
|
|
---|---------------------h............ (AC)
| |. | |
| / .Do f c| |
|/ . a o| = d
| | n n| a
| | d| m
| |--------p------|--p--p
| .| condenser | e
| Di. \ inlet air | = r
| . \ | |
------------------------- (dehum)
|
|
|
floor |
--------------

It might look like this from the inside:

| |
| window |
|-------------------------------------------------|
| ----- | | |
| | | | | |
| | | | | |
| | Do | | | |
| | | | | |
| | | | | |
| --p-- | AC | --p-- |
| | | | | |
| | | | | |
| | | | Di | |
| | | | | |
| | | | | |
| | | ----- |
| | | |
-------------------------------------------------

It might look like this from above:


--------------------damper-----------------------
| |
| |
| p |
| |
| |
| ----------------------------- |
| | | |
| | | |
| | | |
| | | |
| p | | p |
| | | |
| | | |
| | | |
| | AC | |
| | | |
| | | |
| | | |
| | | |
| | | |
| | | |
-------------Do-------------------------------------Di---------
| |
| |
-----------------------------

Nick