5 Ton GSHP Build

randen · 10-22-15, 10:09 PM

Well yes my calculations are a little off the cuff. The proper formula for calculating the wattage of the three phase motor is this: (210V x 5.8A x .82pf x 1.732) / 1000 = 1.73 Kw
Still a little more than the power of a hair dryer.

I also realize I must calculate the efficiency of the VFD and the power the circ. pumps use.

Also as Tech Shop pointed out calculating the energy transferred in the flow rates through the HX would give a better idea of BTU output.

But reviewing the flow charts for the Grundfos Circ. pumps would still only be a guess. A true measurement with a flow meter would be the best at giving a accurate transfer rate.

I guess what I was trying to convey was the subtle adjustments in the TXV and refrigerant (r290) charge that really improved the performance in the air-condition mode also extended its charm when the lever was flipped to heating.

I really wasn't expecting that the machine would have overpowered the air-handler at such a lower power setting via the VFD.

The photo is the first build attempt which provided a better measurement of efficiency using the known volume of water for COP calculations

Randen

10-22-15, 10:09 PM	#22
randen Uber EcoRenovator Join Date: Apr 2011 Location: Strathroy Ontario Canada Posts: 657 Thanks: 9 Thanked 191 Times in 129 Posts	5 Ton GSHP Well yes my calculations are a little off the cuff. The proper formula for calculating the wattage of the three phase motor is this: (210V x 5.8A x .82pf x 1.732) / 1000 = 1.73 Kw Still a little more than the power of a hair dryer. I also realize I must calculate the efficiency of the VFD and the power the circ. pumps use. Also as Tech Shop pointed out calculating the energy transferred in the flow rates through the HX would give a better idea of BTU output. But reviewing the flow charts for the Grundfos Circ. pumps would still only be a guess. A true measurement with a flow meter would be the best at giving a accurate transfer rate. I guess what I was trying to convey was the subtle adjustments in the TXV and refrigerant (r290) charge that really improved the performance in the air-condition mode also extended its charm when the lever was flipped to heating. I really wasn't expecting that the machine would have overpowered the air-handler at such a lower power setting via the VFD. The photo is the first build attempt which provided a better measurement of efficiency using the known volume of water for COP calculations Randen Attached Thumbnails