DickDV
Member
thread carried over from "can VFD's on motors do magic?"
The first question that needs to be answered on the combustion air fan system is whether variable speed is useful or not. Resizing the motors and throttles down to the actual demand will save slightly more energy than doing it with inverters.
On the other hand, for very little extra energy (about 4% of the load kw), you reduce get the benefit of precise control and, if you retain the existing motors, the easy increase of future system capacity. If you downsized the motors AND added drives, you would reduce the inverter losses to 2% of load kw but you would not have the ability to expand easily.
That's the fundamentals of it as I see it. Its your call!
The first question that needs to be answered on the combustion air fan system is whether variable speed is useful or not. Resizing the motors and throttles down to the actual demand will save slightly more energy than doing it with inverters.
On the other hand, for very little extra energy (about 4% of the load kw), you reduce get the benefit of precise control and, if you retain the existing motors, the easy increase of future system capacity. If you downsized the motors AND added drives, you would reduce the inverter losses to 2% of load kw but you would not have the ability to expand easily.
That's the fundamentals of it as I see it. Its your call!