Dayton Furnace model GFS9100C16UP11H

[KEVLAR9981]

I have a customer who wants me to install a 2 ton evaporator coil and a 2 ton condensing unit. He has a Dayton furnace which has a plenum opening of
20x21.The largest 2 ton evaporator coil my supplier handles is a 16 inch.
The supplier said it will work.
Here is the question I pose to you.
What complications will arise by reducing the plenum opening to 16 inches?
I personally think the risk will come during the heating season.
I am worried about the heat rise.
I am unable to get any manufacturer data from Dayton.
It would be ideal to find a cased evaporator coil.
Any help will be very appreciated.

[beenthere]

Its a rebranded York.

Going to have a hard time slowing the air flow down to 800CFM with that furnace.

Thats 100,000 BTU input upflow with a 4 ton drive.

[sktn77a]

You can use a coil that's larger than the furnace dimensions but you shouldn't use one that's smaller. Check another supplier.

[KEVLAR9981]

You nailed it.
I prefer only one time on the fix.