Home Improvement → Re: [HVAC] Manual J and heat pump sizing

A few years ago Trane had a unit using variable frequency drives on the reciprocating compressor. They were expensive so I didn't investigate. Evidently there were many problems as Trane stopped offering them.

Tech told me last year that they were working on the concept so maybe it might come back. There are many VFD's available and have been for years. The problem must be with controlling the pressures of the gas.

The variable speed air handlers have a VFD for the fan motor. I'm surprised Trane isn't throwing out the "Inverter" word to describe it.

Inverter is just the new buzz word manufacturers are now using on clueless consumers.

Looks like they still do offer a variable speed:

»www.trane.com/residentia ··· at-pumps

As well as Carrier:

»www.carrier.com/homecomf ··· -25vna0/

Sure does Tex. That would be great but I wonder if it's really going to be worth the cost?

I have a 16i 2-stage condenser and variable air handling unit and that was very expensive.

I don't know what they cost, but I'm sure they are very proud of them. Of course, two-speeds aren't cheap, either. Who knows how many years it would take to reach a break even point.

I had a Greenspeed 3 ton unit priced for me 2 years ago. They wanted nearly 10k just for the equipment. We do have a 4 ton Greenspeed in one of the offices at work though and it works really well, and is very quiet.