Heat Exchanger question

We are hooking up a unit that was relocated. In the piping they have a refrigerant heat exchanger from liquid to suction.
Air cooled Copeland, inside unit outside they want us to convert.
I stated that they have to put a fan on the compressor, put a suction line accumulator on it, crankcase heater and fan cycling since it gets zero up here in Ohio. BTW, its 404A
Question is, Didn't Jim Lavell (Spelling) once say he didn't like heat exchangers on the new refrigerants? Should I take it out? What's the rules for heat exchangers?
I think Jim may have stated that it could be a problem with those with glides but I can't remember. Heck, I'm not sure if it was Jim that mentioned it either, but I know I heard it.
Thanks Rich
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Rich I don't like you attitude but here is advice for you anyway!
#1 Heater exchanger you are talking about is liquid sub-cooler #2 I know Ohio gets little cool but where compressor and receiver is going to be located inside or out #3 what is range of temperature is going to be used on #4 When unit reaches desire temperature will it remain running or will it cycle off at that temperature.
For out side commercial job let say -20F. yes you should have accumulator and in addition it must have liquid solenoid valve which it should be on pressure switch activated at low pressure allowing compressor to pump down before it start to cool. yes you fan should be control by pressure switch in addition if unit will run continually you should also have head master vale. yes if compressor is out side you should have crankcase heater. yes if condenser and receiver is out side receiver also should have heater rap around. yes if is using oil separator it also should have raped around heater controlled by compressors discharge temperature. If anybody dispute this I am tell them to flush they heads down toilet bowl these are facts of life like it or not. Good luck from Dido

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I have wondered why people in the North do not rig up a system with a condenser inside and also one outside and use something similar to a reversing valve to switch from one to the other as temperatures dictated. You would not have the problems with low ambient, and the heat inside would be beneficial a fair amount of time. Here, low ambient is not a problem, and the heat inside would be beneficial for so little time that it would not be practical. Heck, maybe they do have systems like that already. I have heard they have heat reclaim systems on supermarkets and such. I have never done any large refrigeration, and been in S. Tx for over 50 years, so I dunno. Just curious, Larry
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geoman wrote:

injection cooling as it is</b>

<b> The glide is so small on 404A that it doesn't matter,keep in mind that it is a near azeotropic refrigerant mixture. I would keep the exchanger in line and mount it outdoors</b>

Thanks, Fat Eddy, visit me at
www.hvactalkforum.com
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Keep the HX it increases efficiency, forget about adding a head fan if the compressor didnt come with one you dont need it, use a headmaster instead of fan cycling.
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wrote:

Exerts From Copeland Refrigeration Manual EFFECT of SUB-COOLING LIQUID REFRIGERANT By Superheating The VAPOR. A suction gas to liquid refrigerant heat exchanger is frequently used for the "FOLLOWING REASONS"
1 To raise the temperature of retune suction gas So frosting or condensation will not occur on the suction line.
2 To sub-cool the liquid refrigerant sufficiently to offset any pressure drop that might occur in the liquid line, and prevent formation of flash gas in the liquid line.
3 To provide a source of heat to evaporate any liquid refrigerant which might have flooded through the evaporator, thus preventing the return of liquid refrigerant to crankcase.
4 To increase total system capacity.
Now question is do you need increase in capacity? As for compressor head fan you do not needed for that condition. If you want good working system you need both controls on condenser fan, pressure switch and head master ? Switch alone to much fluctuation in liquid pressure. Head master alone it require large receiver to store the gas, doing hot summer days, and in winter must have some reserve around 20% to maintain effective cooling, it also must be able to store what ever is in the condenser and evaporator, by use of both controls you can reduce size of receiver and refrigerant from 1/4 to 1/3 of capacity been used. However everybody have they own opinion and I am talking from my own experience.
Dido say that www.cas-environ.com
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wrote:

I know all of this, and once again, I'm specifically asking about the sub cooler with some of the new refrigerants. I remember explicitly that some manufacture/rep stated that with some refrigerants you do NOT want a sub-cooler in the line. I believe it was with gas's with a wide Slide too them. This is the information that I require.
Also, I would love to put a head master control on, but the cost of it with the additional reciever isn't an option. With an air cooled compressor however we need air over the compressor. I suppose that if the owner doesn't want to pay for it he will buy a compressor sooner from me than he wish's, but I'm not putting one on without them paying for it.
Back to the question:
Considering the new refrigerants, what refrigerants should you NOT use a sub cooler with?
RIch
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