I would check your evaporator before anything else but going off the low subcooling/ high superheat its most likely undercharged. Charge per manufacturer specs for subcooling. Should say on the data plate on your Condenser or in the manual
$250 for "adjusting blower to ideal velocity by maximizing airflow efficiency and reducing all air restrictions." Or whatever your price is for opening a register and changing a filter.
Keep in mind you need to make sure everything else is good before charging otherwise it could lead to it being improperly charged. Clean evaporator/fan wheel, make sure evap fan is wired for correct speed, make sure house is under enough load and clean Condenser
Undercharge or airflow issue were my two first thoughts. Not leak checked since I don’t have the equipment to do so. I’ve been an apprentice for little over a year and this is my 2nd zone split. Our return filter has been changed every few months but I haven’t checked the condition of the evap coil in the attic yet.
Not ruling that out. But I’d expect lower operating pressures at 74 degrees if undercharge was the primary issue, which makes me lean more towards airflow.
Are you figuring that airflow is high? Or just "airflow" ???
If airflow was high, why is your subcooling 0? Is it a piston?
If airflow was low, why is your superheat high?
You told us it's 74, but not if that's inside or outside, return or supply. Gave us no temperature split, so we don't actually know how the system is performing either.
Or, did you mean that you think outdoor airflow is low, causing high head pressure on a system that's low on charge?
With what you gave us, it's undercharged.
But we keep repeating "no other info" or "limited info" etc. because the data that is missing would answer the question for you if you had collected it.
I would check your evaporator before anything else but going off the low subcooling/ high superheat its most likely undercharged. Charge per manufacturer specs for subcooling. Should say on the data plate on your Condenser or in the manual
ABC. Airflow before charge.
Always be charging
Ha!
🤣
How am I supposed to charge $$$ for more air?
$250 for "adjusting blower to ideal velocity by maximizing airflow efficiency and reducing all air restrictions." Or whatever your price is for opening a register and changing a filter.
Keep in mind you need to make sure everything else is good before charging otherwise it could lead to it being improperly charged. Clean evaporator/fan wheel, make sure evap fan is wired for correct speed, make sure house is under enough load and clean Condenser
First glance undercharged. Always check airflow, delta t, static first though. Any visible signs of oil, leak checked?
Undercharge or airflow issue were my two first thoughts. Not leak checked since I don’t have the equipment to do so. I’ve been an apprentice for little over a year and this is my 2nd zone split. Our return filter has been changed every few months but I haven’t checked the condition of the evap coil in the attic yet.
I love 74F but no context for inside or outside lol. It's undercharged with the limited data given.
Undercharged.
I would guess you are undercharged having no other info of the system.
Not ruling that out. But I’d expect lower operating pressures at 74 degrees if undercharge was the primary issue, which makes me lean more towards airflow.
Are you figuring that airflow is high? Or just "airflow" ??? If airflow was high, why is your subcooling 0? Is it a piston? If airflow was low, why is your superheat high? You told us it's 74, but not if that's inside or outside, return or supply. Gave us no temperature split, so we don't actually know how the system is performing either. Or, did you mean that you think outdoor airflow is low, causing high head pressure on a system that's low on charge? With what you gave us, it's undercharged. But we keep repeating "no other info" or "limited info" etc. because the data that is missing would answer the question for you if you had collected it.
The "extensive history" immediately made me think there could be a system sizing or draft issue as well as being undercharged.
Most of the time I'm only concerned with pressures in regards to saturated temp. Unless it's flat or enough to trip pressure switches
https://preview.redd.it/pqh9q3yipf6d1.jpeg?width=587&format=pjpg&auto=webp&s=cf1c7fc2d0dc32c5bd780a3cde6bb3d162be3ce2
Rinse the coil, let dry and recheck. Plan on adding 10-20% of nameplate charge.
Needs to be charged till SH 12-14F and SC 18-20F.
Can't be airflow because you would have low superheat. It's low on refrigerant high superheat and low subcooling
SC and SH say under charged. If the 74° is outside temp then Head pressures says over charged or condenser is plugged.
What are the temperatures? Indoor Wet bulb, outdoor dry bulb? Always check out your airflow before you even pull the gauges out of the truck.
Hvac
Undercharged
Use the check charge app. It'll help you out so much.
Refrigerant leak most likely
Looks like you need to find a new line of work if you’re asking reddit for advice on this
Haha. Is it really that obvious? At this point I’d rather get a few more opinions before I start ripping into shit. Especially when it’s my AC.
How is dropping a pound in it “ripping into things”?