VFD for a 3 Ton residential air compressor

[anking]

Hi.

I really get into idea of making my own custom made water cooled home AC system with capacity control based on how many rooms need cooling.
I'm going to use zoning dampers to cut off the rooms & ECM motor to control the airflow.
But on the ac side I'm not sure yet if I have to buy a copeland digital modulating scroll compressor(which seems to be very pricey for my own project) or put a VFD on a 3phase scroll compressor.

The large enough VFD for 3 ton machine should be around 4HP? I found one on ebay relatively cheap for 135(item #290520222870) & compressor for 260(item #190755360553)
My question is: VFD will be tough enough to carry LRA load of 88A on this compressor? & if yes, then how far with modulating of its speeds i can go up & down?

thank you

[xarralu]

[kirkH]

you will have oil return problems if you try to run a compressor at less than full speed.

[ryan1088]

you will have oil return problems if you try to run a compressor at less than full speed.

True, but I'm wondering if you could add an oil separator? Some mini split manufacturers go into oil recovery mode every hour where they ramp the compressor to 100% and open all expansion valves wide open.

Are you wanting to use the vfd for a soft start or capacity control?

[behappy]

I might be easier/cheaper to install an IAQ system.......

[jbeckham]

i envy your enthusiasm, but i do not envy your journey...

[mark beiser]

double..

[mark beiser]

I think that by the time you got it all sorted out, you may find that starting with an actual variable capacity system would have been a more economical choice.

For my house, I'm going with a Daikin VRVIII-S system, with a conventional ducted air handler for the main living/kitchen area, ductless wall hangers for the bedrooms, and a ceiling mount for the garage.

[grkmano]

I think that by the time you got it all sorted out, you may find that starting with an actual variable capacity system would have been a more economical choice.

For my house, I'm going with a Daikin VRVIII-S system, with a conventional ducted air handler for the main living/kitchen area, ductless wall hangers for the bedrooms, and a ceiling mount for the garage.

Nice system..

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[ryan1088]

Nice system..

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X2

[jbeckham]

I think that by the time you got it all sorted out, you may find that starting with an actual variable capacity system would have been a more economical choice.

For my house, I'm going with a Daikin VRVIII-S system, with a conventional ducted air handler for the main living/kitchen area, ductless wall hangers for the bedrooms, and a ceiling mount for the garage.

I've had my eye on those conventional ducted Daikin units for a while. Let me know how it performs. Also, what capacity did you select for it?