using 404a in high temp apps.

[liptow]

Hello fellow enthusiast of refrigeration,

What does a designer have to do to get r404 system
properely designed to function for a working cold lab with set-point of 4C/40F.

The evap is ceiling hung and room loads are commonly 8-12k btuh. FA is minimul and the room is made from insulated foamed panels.

I ask this because they want either r134a or r404a/ 460V-3P/semi-hermetic/air-cooled/Copeland. This is not supplied in r-134a but they do have a 1Hp unit in r404.

In working cold labs we don't like to have the LAT more then 10F below the room temp. Are there tricks to fool the system. Thanks, Joe.

[Electrocoolman]

Hi,
a few thoughts....

Most evaps are duty rated for R404a, so no correction factors necessary.

Need to work out heat load of room for selection of evap

An oversize evap will allow for lower airspeed fans (less noise) and higher humidity.

Whats the duty of the condensing unit.?

[Peter_1]

You can charge your R404a compressor without any problems with R134a. (not vice-versa)
Only compare the swept volume you need for your application.