404a for positive temp cold rooms?

[expat]

Hello all, I wanted to ask some advice on condensing group choice for a vegetable and fruit cold storage room on a farm.

The customer wants a quote for two 8m*6m*2.6m cold rooms. As he wishes to recuperate a group he already has for one cold room I only need to quote for one condensing group.

The suppliers I have contacted have both quoted groups with comps running on 404a.

1 Unité Hermmétique TFH 4531 ZHR (5.99kw @ 0°c)

2 Copeland H8-LF-30X (9.24kw @ 0°c)

I thought 404a was better for low temp aplications and 134a would have been preferable.

Has anyone got any comments on the use of 404a in positive refrigeration, and or any harm that may come to the compressor if it's not doing the job it was designed for?

Thanks in advance

[smpsmp45]

Recently after lots of issues on HFC gases, etc, we have been using R 404A for all the applicaitons including low as well as medium temp. We do not face any problems whatsoever with this gas for such applications. Ofcourse it is expensive compared to R 22.

[expat]

Thank you for that, I didn't think the suppliers would be making an error but better safe than sorry so I thought I would check with the experts;)

[smpsmp45]

YEP. We also went through the same phase when we suddenly came across units with R 404A for Positive temp.

[thermo prince]

From transport aspect, today most of the bigger truck & all trailer equipment is all 404a. No adverse effects on recips, scroll or screws. Regardless its deep frozen load ( like ice, frozen meats & fish) , dairy or produce trailers : there's ONE refrigerant only -404a.
In the CFC days, customers could specc units r12 for producr/dairy/chill temps and then r502 for the 'low temps' down to -29C (-20F).

Some may argue that 404a is 'overkill' for positive ( above 0deg C) temps but that's just the way things are going - rationalization of product lines and options, inventory mgmt. However' there's no technical impediment to converting a unit 'back' to 134a in the field

Small delivery vans can still be speccd with 134a or 404a however - application issues.

[pendlesteve]

I select using R404A whenever possible due its better performance. There is also some speculation the R134a has a doubtful future as a stand alone refrigerant.

[expat]

Thanks again all. You might be interested in the software on this page

http://www.bitzer.de/home/index.php?LNG=EN&CTR=USA&CMP=USA&NAV=1&

You can try different comps on different refrigerants to the the capacity. Worht a look if you don't already know it.