View Full Version : old bitzer open drive

03-10-2013, 05:54 AM
Hi all
I'm on a job at the moment and we are looking to swap out the old compressor on a freezer room to gain some energy savings for the client. It's an old open drive bitzer on 404a, the name plate is all but gone the only numbers I can get off it are
11 0 63A.

Or if there are any options with the existing comp. Have been looking in to vsd for evap fan motors, condenser fans and soft starter for comp motor.
Dose any one have any ideas on a system this old. or is swapping out my best option.

Any help would be great

03-10-2013, 08:01 AM
Unfortunately looking at that picture (lovely old single cylinder bitzer) the motor insulation class would probably not take an inverter and with a belt drive you need to be careful of slip when slow starting.
The best energy saving in this situation is unfortunately to replace due to age and condition. I would steer away from R404a for a long term refrigerant.

03-10-2013, 03:13 PM
Hi it looks like mk 5 o/type

03-10-2013, 05:45 PM
By looking on that picture, best for you and client is to swap to new system with hermetic compressor.;)

08-10-2013, 12:25 AM
Its running on 401a, I think from the markings on the dryer.

08-10-2013, 10:22 AM
Hi Whitefridge,

The term "energy efficiency" is a bit of an oxymoron respective to "old bitzer recip"

Please feel free to correct me as I am only guesstimating & generalising.


If the "old bitzer recip" costs $1000 in electricity per quarter to operate, i.e. $4000 per year / $8000 per 2 years.

10% saving would be considered reasonable, 20% good, 30% great & 50% impossible.

Payback is generally desired within 2 years.

So, at $8000 electricity for two years, 10% = $800, 20% = $1600, 30% = $2400, these amounts represent the budget that should be considered for efficiency improvements relative to efficiency improvement.

$800 dollars barely covers me for a day of labour rates (no parts)

$1600 covers me for one day plus $800 parts / equipment, so on for other amounts.

For this system, I am not familiar with any product that costs $800, which I can install in one day, that will save 20% in electricity.


One single service call can easily cost $800. Reduction or prevention of a single service call may represent the equivalent saving of 10% energy reduction over 2 years.

Given this kind of situation, the nuts and bolts stuff might yield more tangible results than energy efficiency modifications per se.

I'm sure you have heard it all before - clean condenser & evaporator, insulate suction pipework, keep on top of leaks, ensure full charge of refrigerant, check superheat, check defrost blah blah..

About the only "new gadget" kind of thing I could suggest is EC style evaporator / condenser motors - but I'd only bother if / when the existing item/s fail.

Replacement equipment (condensing unit etc) should be considered if existing equipment has disproportional costs of operation (servicing, repair & electricity)

08-10-2013, 08:14 PM
These open drives are used in a big way on trawlers here, this suggests they put up with gods own abuse, easy to strip and service, if it's working would you not keep it and make any changes at the evap side, wait for it to seize and then replace it.

This reply was brought with to you in conjunction with Erdinger ale


09-10-2013, 11:26 AM
Find out piston swept volume & calculate the displacement .......and match it for an euivalent model ....

The Viking
09-10-2013, 03:17 PM
Now this brings back some old memories...

These open Bitzers were old fashioned already back when I did my apprenticeship.
We used to rip them out and replace them with modern semis.
Sadly my time as an apprentice is now a memory in the distant past and a lot of water have passed under the bridge since then, so can't give you any details of the compressor (but I do believe Mr GHAZ might be right in his post above)
Another way to find the duty is to look at the evaporator and the expansion device to see what they are rated at.

However, you say that this is serving a walk in freezer...
This kit, and it's evaporator if it's of the same age, should be replaced not for energy efficiency reasons but for reliability. How much does it cost them when the system fails and they have to throw away the produce in the room? That's the money to spend on the new system.