400 CFM/Ton ???

[Gary]

The comfort zone for humidity is 40-60% RH. I set the lower limit at 'SA 25F below room temp' because lower than this can result in dropping the humidity below 40%. This is not only detrimental to humans and their furnishings, but is a waste of energy. And even in the most humid areas, the humidity load varies. On a less humid day, we don't want to drop the humidity below 40%.

The other lower limit would be coil freezing. This can be difficult to judge. The coil temperature is going to be somewhere between SST (saturated suction temp) and SA (supply air temp). If the SST is at or above 32F, we needn't worry about the coil freezing. I have seen systems running as low as 26F SST without freezing, but this is cutting it far too close. I like to see SST at or above 32F.