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Abe
14-06-2003, 10:59 PM
Would R22 work in a R407C system ??
I know some smart alec will say.............Why ??

Gary
15-06-2003, 12:02 AM
High, medium, or low temp? Cap tube or TXV?

The pressure difference would be sufficient to drive a TXV crazy.

Also, R22 doesn't carry oil very well at low temps. That's why R502 was invented.

frank
15-06-2003, 04:44 PM
Do they make TEV's for R407c?

Every application where we have purchased TEV's for R407c we have been given R22 TEV's?

Prof Sporlan
15-06-2003, 05:21 PM
Net refrigerating effect of R-407C runs about 2 percent less than R-22 at for a/c applications, and its liquid density is also less than R-22, resulting in an approx 6 percent reduction in flow thru an orifice. But R-407C runs higher condensing and lower evaporator pressures than R-22, and the resulting increase in pressure drop effectively cancels out the above reductions, at least with respect to orifice flow.

In other words, an R-22 TEV on an a/c system converted to R407C won't shortchange the system. :)

R-407C runs lower suction pressures than R-22, about 7 psi less at 40F, which will have a tendency for the R-22 TEV to run lower superheats or perhaps flood. The Prof has seen this with R-22 chillers converted to R-22. Valve adjustment normally remedies this situation.

The Prof hasn't seen much in the way of R-407C refrigeration systems yet.

Prof Sporlan
15-06-2003, 05:32 PM
Do they make TEV's for R407c?
Yes, Sporlan, for one, has a special thermostatic charge for R-407C that has been used for the chiller market. It is a slightly adjusted R-22 thermostatic charge to provide a better adjustment range for the TEV used on R-407C.


Every application where we have purchased TEV's for R407c we have been given R22 TEV's?
This is typical, and should not present any problems. Keep in mind there are still lots of R-22 TEVs and systems being manufactured, and the usage of R-407C is, at the moment, small in comparison. A manufacturer producing both R-22 and R-407C units will find it desireable to stock only the R-22 valves.

Abe
15-06-2003, 11:30 PM
I was thinking of an air conditioner running on R407C, which are now common in the UK. In fact you cannot now get any air conditioners running on R22, and it is illegal for manufacturers to produce them on R22.

R407 is in my "opinion" not the ideal refrigerant. The only reason why we are getting units running on R407c is because manufacturers dont wish to fall foul of the PED , Pressure Equipment Directive which forces manufacturers to provide additional controls, safety devices on systems running R410C.

By using 407C , manufacturers can get away with it, for some reason and not have to comply with the PE Directive.

For our US members, a Directive is European Law and is binding upon all member states of the EC.

Eventually all air conditioners will come with R410 , which as everyone knows has twice the head pressure of R22. But they reckon its good.

So R407c is a sort of interim measure and we are lumbered with it on this side of the pond.

Now back to my question, say I was in some non EC country, lets say in Papua New Guinea, and the air con ( R407C) has run out of gas. I only have a bottle of R22. If I charge the system up with that.................Will it work???

For all you prudes in the EC..............remember Im in Papua New Guinea, ok.............so I dont want a headache

Prof Sporlan
15-06-2003, 11:59 PM
say I was in some non EC country, lets say in Papua New Guinea, and the air con ( R407C) has run out of gas. I only have a bottle of R22. If I charge the system up with that.................Will it work???

If the TEV is adjustable, you should have no problems getting it to work properly. With a non-adjustable TEV, one can get the system to "work", albeit at a higher superheat control than ideal. Even if the system had a restrictor, one should be able to charge it to an appropriate superheat.

Abe
16-06-2003, 08:34 PM
Thanks Prof and Marc............youve made my day...............Im off to Papua New Guinea now.....................lol

Just hope those "guys" out there dont fancy a bit of curry meat and start smacking them lips, wanting to eat me!!!!

No offence to any forum members from Papua New Guinea !!!

Just to enlighten my US freinds, ( Who dont seem to understand / appreciate my brand of humour) Isnt PNG where human flesh is a delicacy ?

Our Aussie mates can confirm this

Andy
17-06-2003, 07:46 PM
Hi Marc,
does he work for the same firm that I do:confused:
Or where do I know that name from.:o
Regards. Andy:)

baker
20-06-2003, 08:51 AM
Since you raised the subject:

A chief in the New Guinea highlands is throwing a party so
he goes to the local butcher shop and asks for some long
pig. The butcher says that he has 3 varieties in stock:

American missionary for $30/kg
Australian pilot for $35/kg
English engineer for $120/kg

"$120 a kilo for a pom?" questions the chief.
"Have you ever tried to clean them?" answers the butcher.