inverter compressors

Mitch_4

> I kind of figured it to be something like that, <BR>
> but its always nice to get confirmation on a <BR>
> suspicion, and facts are always better. <BR>
> <BR>
> I <BR>
> would assume such a system required a TXV of AXV <BR>
> type metering device and that a simple orifice is <BR>
> not capable of handling fluctuating pressures <BR>
> properly for Coil operation? <BR>
<BR>

Mitch_4

Hi Profeesor

I have been hearing alot about inverter compressors used on some Asian ducless split units. I am semi familiar with Copelands Digital compressor, but what is an inverter compressor and how do they work?

Thanks.

Mitch

Eugene Silberstein 3

Sorry for the delay, Mitch

Traditional compressors operate at two speeds: Full speed and off. So, as long as there is a call for cooling, the compressor will operate at full capacity, even if the heat gain on the structure is low.

Inverter compressors ramp their speed up and down just as our newfangled ECM motors do.

As the cooling capacity requirements of the space change, the frequency of the power supplied to the motor changes as well. This reduces the system capacity when the heat gain is low, therey reducing the amount of power being consumed. During periods of high load, the compressor turns at maximum speed to satisfy the heat gain.

From what I have heard, these systems operate to satisfy the cooling (sensbible) load quickly and then operate at a much lower speed to maintain the desired temperature and control the humidity.

Mitch_4

Thank you sir

I kind of figured it to be something like that, but its always nice to get confirmation on a suspicion, and facts are always better.

I would assume such a system required a TXV of AXV type metering device and that a simple orifice is not capable of handling fluctuating pressures properly for Coil operation?

Eugene Silberstein 3

Sorry I Missed Your Post

You would think...

Larger industrial systems that utilize inverter technology do use TXVs, but such was the case even before the inverter technology became more popular.

On smaller, residential systems, such as ductless split systems, capillary tube type metering devices are used.

By slowing the compressor speed, the speed at which the refrigerant moves through the system is also reduced. This reduces the mass flow rate of the system and causes the capacity of the evapoartor to fall.

By slowing the compressor speed, we also experience an increase in the suction pressure and a decrease in discharge pressure, which reduces the compression ratio of the system and increased the efficiency ratio.

Very clever...

JackFre

Eugene,

would you kindly send me your fax number. I have an article I'd like to forward to you on sizing A/C. I can't scan it as I am to dim to operate such a piece of equipment. Thanks!

Eugene Silberstein 3

Fax Number

You can fax me at the office at (631) 851-6361.

Regards

Mitch_4

My Thanks again

No problem about missing the post..I was in withdrawl as I could not get to the wall myself for about a week.

Excellent explanation Proffessor.

Mitch