I'm looking for a manufacturer of a small outside air DX precooling unit in the 300 CFM to 600 CFM size range. I haven't been able to find anything smaller than 700 CFM. Any suggestions?
If you damper it down, hot gas bypass will increase to provide a false load on the compressor, thus wasting energy. Using a 700 CFM unit in a 600 CFM application wouldn't be too bad, but for a 300 CFM application it would be wasting a lot of energy.
I don't know where you are, but this small a unit is hard to find unless you want a fan-coil unit for finished space or you design your own with fan/coil/filters.
York makes a low tonnage air handler (used to be Pace/Brod/McClung) but it is expensive.
Residential units can be found this small, but you can't change the fan type/coil size and etc.
I'm in central Florida where humidity is high most of the time. I'm looking for a small 100% OA DX package unit that will provide dehumidified outside air to a small lab without having to use reheat on the main HVAC unit.
Try Aaon or Addison I believe they make packaged units with this low a CFM. I don't know if they publish the data, but their reps will know. Both make 100% OA units that control both temperature and humidity.