subcooling

[dec]

Have heard that a lot......seems like a lot less hassel then reclaiming and recharging by weighing in.

[HVAC Pro]

Goodman suggests using 126° over ambient for charging their heat pumps in the heating cycle. Most manufacturers post their own methods inside the od unit. Recovery, evacuation, and weighing back in is probably the most accurate, but the most expensive method for the customer.

[arc8]

Why don't you just charge it in the A/C mode and it's over.
The reason why i say this is you ask about this right now and it's summer, not winter. unless you're in the southern hemisphere, you don't need to charge it in the heat mode.
Anyway, i prefer the 126 degree over ambient rule when in the winter i need to charge a heat pump and i don't want be outside freezing.

[hvac-tech-lane]

Originally posted by HVAC Pro
Goodman suggests using 126° over ambient for charging their heat pumps in the heating cycle. Most manufacturers post their own methods inside the od unit. Recovery, evacuation, and weighing back in is probably the most accurate, but the most expensive method for the customer.

Interesting, never installed a Goodman, thanks for the reply.

[j-bill]

the rule of thumb method will get you by in winter, but you always want to have the customer call you back for a spring checkup to properly set the charge superheat or subcooling whichever applies,i know some manufactures are vague about charging,old daves crazy approach method & wrap the cardboard box around the condenser & charge in cooling in below 60 degree weather for example.heatpump charges are only properly set in the cooling mode in at least 65 or above.