Hello there. I own a small commercial building in northern IL, it's a newer single stage 7.5 ton package unit with a single speed belt drive blower, and (as a lot of people have) I have a bad part load humidity problem. I was considering different options to try to correct this problem. I understand replacing the unit with a 2 stage unit, or a unit with dehumidification (hot gas bypass) would help, but I would rather not replace the unit.
I know slowing down the blower speed will increase my dehumidification, but I do not want to freeze my coil or overheat the heat exchanger when winter comes, so I was thinking of a more versatile approach then then just statically setting the blower speed lower. After, do a lot of reading, I was wondering how feasible is it to install a VFD to the blower motor? It's a fairly small motor, and VFD pricing is not so bad for loads this size. Could this be used to control the speed of the blower motor successfully, taking logic factors into consideration (obviously by adding other devices to the system) such as call for cooling, humidistat signal, coil temperature? Also, could it even be taken a step further to allow for soft starts which should help with motor and belt life, and even perhaps slower operation of the blower for fan only calls?
Thanks in advance.