converting freezer to cold room

[glenn1340]

Hi guys,
A customer of mine has taken over a small supermarket premises that has a walk in cold room and freezer. As it`s now an Indian vegetarian food shop he`s no need for a freezer and I`m pre-empting his question " can you up the temp to make it run as a cold room at 6c" Now, I know it`ll not be as efficient using a low temp system for a cold room but will the increased return pressure and possibly temperature cause problems for the pump or will it just be a matter of replacing the thermostat and adjusting any defrost timer etc.

Many thanks in adavance
Glenn

[chemi-cool]

You are inviting problems, Evaporating temp will still be low so you need to defrost every so often.
Capacity will be much higher at working times and I would worry about too high head pressure and compressor cooling.
On the other hand I have seen freezer rooms that just the set up temp has been change and no special problems.
I believe that if the unit is well designed and built it will do the job.

[monkey spanners]

It may be worth fitting a crankcase pressure regulating valve, most dual temp room have them fitted to allow them to run as a freezer or chiller.

Jon

[chemi-cool]

It may be worth fitting a crankcase pressure regulating valve, most dual temp room have them fitted to allow them to run as a freezer or chiller.

Jon

If its a hot gas defrost, its a must.

[tonyelian]

hj
freezer room has a smaller evaporator so you might have an humidity issue due to the low evaporating temperature
also it has a smaller condenser so you might have a head pressure issue
if you have a large condenser change the expansion valve and every thing will b ok

[Peter_1]

'Converted' on 1 place 2 freezer rooms (2 x 2x 2 m ) to cold rooms last week, only changed the set temperature.

[Peter_1]

hj
freezer room has a smaller evaporator ..

This needs for me more explanation

[DTLarca]

This needs for me more explanation

For the same capacity and TD the freezer blower might have to be bigger because it would have a larger fin spacing which would need to be compensated for by longer or more tubes.

But when speaking kW/TD, with the same compressor, the freezer blower will be selected smaller only because the compressor capacity at the lower SST will be lower.

I have attached a powerpoint slide that shows when the same blower is used with the same compressor in a -18°C room it will have an operating TD of about 6K but then when the room is 2°C the operating TD would be about 13K if the TEV could deliver the higher required refrigerant mass.

[Peter_1]

OK, this makes sense