Next refrigerant to replace 404a

[mmmdave]

Honeywell and others are developing next generation refrigerants that have lower GWP. They are HFO's (hydro-fluoro-olefins). Potential replacements for 404a are currently know as N-20 and N-40. These seem to be a few years out, at least...

[hvac wiz 79]

I don't mind 404 or POE in general. I'm finding just about every expansion valve with gunk from minimal to large amounts. Keeps the company busy. It sucks when I find few month old boxes with fouled up expansion valves because the end user typically suffers as they have to assume labor.

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[Muz]

So whats the push on going "green" over there? we havent got a phase out date on 404a yet but with our "carbon tax" its really dear! (in oz)

so is there word on hydrocarbons? c02? or just more synthetics?

>Muz

[jpsmith1cm]

So whats the push on going "green" over there? we havent got a phase out date on 404a yet but with our "carbon tax" its really dear! (in oz)

so is there word on hydrocarbons? c02? or just more synthetics?

>Muz

hydrocarbons have been approved in VERY small quantities.

Co2 is making some inroads, but isn't accepted by everyone, yet. The different CO2 systems (chilled fluid, cascade and transcritical) and higher operating pressures scare the snot out of people who just don't care to educate themselves about the system and the way the various systems work.

I've been hearing some noise (and have seen a LITTLE action) on a return to ammonia as a primary refrigerant to chill a secondary fluid. Of course, the easily frightened will find reasons to eliminate that as well.

[Muz]

thats a shame, c02 is a good referigerant, yes we have a ratio for the percentage of hydrocarbons in an aera.

ammonia is still used here in large systems, eg slaughter houses, milk processing and bottling, etc. but not supermarkets, c02 is now the new thing for supermarkets, using sub-critical casscade systems witch seams to be stable and replaces 404A systems, also mid temp and low temp run off the same c02 rack.

we have also had alot of resistance with c02 and HC's, its a shame they have there place & work well in the right applications.