[NiHaoMike]

Originally Posted by MN Renovator

If the indoor coil has more surface area, you might get more EER/SEER out of it but when cooling that extra surface area can diminish some of its dehumidification capability because the coil needs to be saturated before the water starts to run off of it and once you've met the temperature demand of the cycle and it shuts off, all of the water remaining in the coil will evaporate back into the air after the cycle and be return to the building. Taking a look at the AHRI ratings for 1.5 ton and 2 ton units of the Bryant variety in their 16 SEER models, I'm usually only seeing a boost of about 1/2 SEER by jumping from a 2 ton to a 3 ton coil. I'd rather sacrifice a partial SEER point and have better dehumidification and get a condenser and blower that are as efficient as they can be if I'm going with a central air unit because reducing latent heat(removing moisture) is very important, it isn't just about removing sensible heat(reducing temperature).

You decrease the airflow to regain the dehumidification lost by upsizing the evaporator. The net efficiency still improves, especially if you're using an ECM fan motor and a humidity sensor to vary its speed.