I have a challenging project here, constant volume of air for high fitlration rates, a high amount of outside air and I have to maintain 68F and humidity in the 50 to 60% range. No outside walls, no roof, no external heat gain.
So I am using a custom chilled water air handler with a built in 7.5 ton dehumidifer.
Had to have it built in two pieces it has to fit through existing mechanical room doors.
This is the coil section, you can see the 2.5" coil connections for a chilled water coil in the back. The coil visible in the front is a heresite coated condenser-reheat coil
This is a DX evaporator coil which is down stream of the chilled water coil and upstream of the condensing coil
This is the compressor, it turns on when there is a call to dehumidify, its DX coil gets air down to about a 48 dew point, the condenser coil reheats the air and when combined with the heat the fan and motor add, it will supply air at 65F with the low dewpoint.
BAF fan and 15 hp Premium efficiency motor - there are external filter banks in the duct work, fan will be up against about 6 inches of total static