Digital V/s Inverter Technology

[munesh]

Thanks Everybody! It was nice getting all the replies. It is quite useful.

[mohan]

Advantage inverter based compressor is its capacity variations on variable load conditions.

For example if your peak load is 10TR and average load is 7TR, you can use 7TR compressor @60Hz same compressor can deliver 10TR @90Hz.


Incase of digital if your peak load is 10TR you are left with no choice than 10TR.

In digital you can only handle reduced loads.

[nike123]

Advantage inverter based compressor is its capacity variations on variable load conditions.

For example if your peak load is 10TR and average load is 7TR, you can use 7TR compressor @60Hz same compressor can deliver 10TR @90Hz.


Incase of digital if your peak load is 10TR you are left with no choice than 10TR.

In digital you can only handle reduced loads.

It is not exactly like that.
Every compressor has motor that need to overcame the reaction force of compression.
So, if inverter compressor could deliver 10TR at 90 Hz and 7 TR at 60Hz than his motor must be of same power as one of digital scroll of 10 TR at fixed speed (60Hz).

Also, capacity variations on inverter is from 30% (very inefficient - low COP) to 130% of nominal capacity at 60Hz (again, with lower efficiency than at 100% load).

Digital scroll can vary his capacity from 10% to 100% of nominal capacity.

Converted in refrigeration capacity, Inverter of 10TR maximum capacity, can vary his delivery from 2.1 TR to 10TR. Digital Scroll of 10TR can vary his delivery from 1TR to 10TR.

It is obvious from above that Digital scroll has broader range of capacity variation.

Now question is how efficient is one in comparison to other at various loads.

The most efficient is compressor whose motor is optimized for one condition. That is fixed speed compressor at full load and design conditions.

Every move from that point mean, that motor is over-sized or under-sized, and that his efficiency is not any more at maximum.