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Discussion Starter · #1 · (Edited)
We've recently experienced a few instances of heat pump units that were installed last summer and charged using the subcooling method that weren't working so well during cold weather.
Once we reclaimed some of the freon (in some cases as much as three lbs.) they were alright.
I've heard other technicians moan about how hard it is to get the charge right and how small the margin for error is with R-410A.
Has anyone else experienced this and could anyone provide some tips on the proper way to charge these new systems? I think we might need to make some procedure changes as we get more used to the new refrigerant.
 

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Allow system some time to get the home/building to a reasonable state(drybulb and wet bulb temp close to AHRI conditions).

A building with a very high wetbulb will have a low SC until the air is brought inline with the units normal operating conditions.

SH should still be checked on TXV systems.

Charge should be weighed in first, and SC and SH checked after the unit has brought indoor conditions to a reasonable level.
 

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yes make sure charged as a liquid ...is a 400 series refrigerant..but still should be vapourized i use a 410 liquid to gas gauge insert from yellow jacket...to insure..i dont hurt a compressor when charging...410a most reliable when charge by weight..have had problems with defrost no correctly working blub placement... freezing up not detection all the time...let me no if this helps
 
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