Equipment Supplier for Medium Temp Situation

[nuuvox000]

I'm doing a design on a small laboratory room that needs to be kept at 50°F +/- 4°. I'm looking for DX fan coil or DX rooftop equipment that can supply air temperatures between 46°F and 50°F. Trane, Daikin, Bohn, United Refrigeration are telling me that they don't have anything that can do this. They either have equipment that does 60° and above, OR 40° and below, seems like a very unique situation. Has anyone ran into this situation?

Just FYI, I would love to do this with chilled water coil but the owner is really set on a DX coil. We also need to have ventilation and exhaust so we are not able to do a typical "walk-in cooler" piece of equipment.

Thanks for your help!

 

[itsmoked]

Yeah, you're in no man's land. One foot in refrigeration and one foot in air conditioning.
Still a robust A/C system should be able to work for you especially with the generous +/-4°.

Better yet. Consider a refrigerated reach-in box. You have coils that have to keep the air temp around 40F. The evaps are a foot to 1-1/2feet long and about 6" across. Use an appropriate condenser unit and a liquid line solenoid and control the refrigeration with an appropriate pump-down function. Once the unit has the room at temp the compressor will pump-down filling the liquid-line receiver and shut off. The thermostat then controls the refrigerant to the evap via the liquid line solenoid drawing on the stored liquid until the pressure finally rises in the compressor low side enough to have the compressor restart. Around and around.

Figure out your refer loading and make comparisons to display reach-in boxes stated capacities.

Keith Cress
kcress -

http://www.flaminsystems.com