possible conversion

[nique]

Ya got to love the enviro's. So I have a building with a big national chain that has two trane rtwa that are r-22 (11yrs old), so for the company to get the green leaf status the units will need to be changed to 134 or be replaced. the question is, can those units be converted or do I get to replace them with a newer version.

[zw17]

You get to replace them.

[R123]

They can't be converted to 134A.

[Nuclrchiller]

Is it still Trane's policy to not convert any Trane R22 equipment?

[motoguy128]

Wow, only 11 years old too. Sell those puppies on the used market. Might fetch enough to cover installation costs at least.

Hey, what size are they? I assume pretty large. Any chance they are 100-200 Tons?

[Screwit]

They can't be converted to 134A.

Nothing is impossible, usually it is a question of the cost.

In this case it is more the conversion is not supported by the factory and the approx 30% capacity loss associated with the conversion. If you can locate literature for ERTWA in the European market which operated under accelerated HCFC plase out of the Montreal Protocol you will understand why I say this (B20 IM 004E).

ERTHA also was available on HCFC22/HFC 134a out of Epinal/Charmes but only HCFC 22 out of Pueblo. There are specific procedures required for the conversion and efficiency/capacity losses which reduces chlorine emissions and direct GWP.

Does indirect GWP come into considreation under the green leaf status?

[Dallas Duster]

MO-99 aka R-438a. Maybe is that a flooded evaporator or DX?

[Screwit]

The RTWA evaporator is DX, next issue affecting refrigerant conversions as the RTWA microprocessor measures refrigerant temperatures and converts to saturated temperatures for functional control. So the new refrigerant properties need to be selected in the configuration.

[nique]

the machines are 90 ton. and yes indirect GWP comes into consideration under the green leaf status. I will do some research on the web and see what I can find. If anybody has some specifics that would be great.

[Dallas Duster]

the machines are 90 ton. and yes indirect GWP comes into consideration under the green leaf status. I will do some research on the web and see what I can find. If anybody has some specifics that would be great.

Well I looked on the web and all of the R-22 replacements seem to have a larger GWP than R-22.

[nique]

ya thats about what i found, thanks for looking.

[Pat A/C]

What voltage are the rtwa and are they in good shape and last question are they for sale

[ascj]

What's wrong with 407c?

[stanbyyourword]

yep 407c saturation temps are close enough to wing it with electronics im sure

[emcontrols]

Right on 407c!!!!!!!!

[Screwit]

I would have serious concerns "winging it" with R407c considering the glide when using a DX chiller vessel working off microprocesser staturated pressure/temperature properties of another refrigerant for the chillers safty protection.

I guess you could fit an external low pressure switch for protection but the chillers reliable operation would be compromised.

[heatingman]

I've seen R407c and R22 use the same thermal expansion valves in some cases.

I've seen it a lot on split systems.

The bigger problem on the rtwa will be oil separation capacity. POE oils blend with refrigerant a lot better then mineral oils, which is why no traps are needed on high temp split systems using poe oils.

[the-man]

Carrier just sent out some info on converting 22 to 407' on a 100 ton machine it's like 17k to convert it. I haven't seen the labor involved . I'm shure if trane would let you convert it would be in the same relm , may want to replace the machines. Don't think it's worth the cost to convert. I don't remember what they said about capacity. Dozed off during that meeting