Looking at a PSE&G customer in Newark with high demand charges from HVAC equipment. Building has 4 large air handlers with 25 HP motors each. Currently seeing 65 kW demand spikes during startup that's costing about $1,300/month extra on their electric bill. Local contractor is pushing variable frequency drives at $3,500 per motor. Anyone have experience with VFD payback on HVAC applications? Seems like a lot of money upfront but the demand reduction could be significant.
PSE&G variable frequency drives - worth the investment?
Tony, VFDs on HVAC are usually good investments, especially with PSE&G's demand charges. 25 HP motors will definitely benefit from soft starting. You should see 40-50% reduction in startup demand plus ongoing energy savings from variable speed operation. At $1,300/month demand savings, your payback on $14,000 total cost would be around 11 months. Plus PSE&G often has rebates for VFD installations - might cut your upfront cost by 20-30%.
Vince is right about PSE&G rebates. Here in Philly, PECO has similar programs. The energy savings alone usually justify VFDs on large HVAC motors, and the demand reduction is just bonus. Make sure your contractor includes harmonic filters though - VFDs can create power quality issues that some utilities penalize. Also verify the motors are VFD-rated - older motors might need replacement to handle the variable frequency operation properly.