Help on Motor Speed Controls

[weressl]

For eight hours a day, 365 days a year at 1.5 HP assuming 85% efficiency, electricity cost per year would be about $330.
If the fan could be run at say, half power by speed reduction, savings would maybe be around $150 p.a.
That might be a hard sell to the pizza place owner if, as the OP suggests, the VFD costs $500 and possibly installation and a new motor on top of that.

That is only part of the picture.

• The efficeincy would be worse than that.
• The power reduction would be 70% or better, unless you have some mayor air leaks,
• I would like to move to an area where electricity is $0.10
• The real savings would not necessarily be in the power savings on the motor, but the reduction in air-conditioning cost,
• There will be further reduction in AC cost as the unit would not 'draw' as much hot air from the pizza oven itself.