4TXCB006DS3HCA coil compatibility with 4ton condenser

[Hillbilly Deluxe]

I would caution you against putting too much airflow across a coil/condensing unit that is undersized.... even 1/2 ton.

If your existing condensing unit is 3.5T, yes, you can put a 4T coil on the air handler, but I would suggest having the fan speed lowered or set somewhere around 1200, 1400 CFM at max. Believe it or not, 1200 CFM on a 3.5T coil/condensing unit will help your situation more than anything.

You will have a higher dehum capacity (latent capacity), it will most likely run longer and be more comfortable.

Blowing a higher CFM across a smaller than acceptable coil will cause problems, the biggest could be increased humidity via lower latent capacity.

 

[parshisa]

ended up putting the window AC on the second floor, helped a ton. One thing I'm looking at now is insulating the attic by installing atticfoil (staples on the rafters and creates a reflective barrier for the heat). Does anyone have first hand experience with such insulation method?

 

[Cujet]

Yes, this is my main suspect now. Is foaming the roof a good option? Or you’re referring to adding more pink stuff (don’t know what it’s called)?

Roof/attic insulation won't help much with radiant heat. The best choice is a white roof.

You could, for example, use 2 feet of blow in insulation in the attic, and still have the same radiant heat inside the house. Foam is not much better.

You could install a radiant heat barrier. This will heat up everything above it, sometimes to the point of absurdity. It will work if well installed. But remember it will trap an enormous amount of heat.