What ambient and what refrigerant ?
Today I was at a call where my low side was 75 psi and high side was around 250 sub cooling is at 13 but I am concerned about the low side being so low also unit sure is t cooling like I'd like to see. This customer is elder with health issues and I require some solutions ASAP
One thing I was thi king I could be wrong but maybe the metering device is not installed ( orfice or tx valve)
What ambient and what refrigerant ?
78f r410a
with those pressures on a 410a system, fixed orifice, high superheat, no cool call, 79* IDDB, sounds like it is a few pounds low on refer, bottom of the coil is probably frozen. that would be my guess but im young in the trade so maybe someone gots something different for ya!
I highly doubt a 14.5 seer unit doesn't have a metering device installed. Whoa at 14.5 seer shouldn't it have a txv? Check the indoor coils if their dirty or the airflow maybe on wrong speed. 75 psi is very low. I hope you dont have a restriction.
A missing orifice would cause elevated suction pressure and low superheat.
Check your coil outside and make sure its clean. What I would do is recover the refer't, cause it sounds like you have a leak somewhere anyway. Your system is low on charge to begin with, take apart meter block and ensure orifice isn't blocked. Put back together and leak check ( fix), take it into deep vacuum and recharge with virgin 410a. The blend of the existing 410a is screwed, the higher pressure refer leaked out. Get your indoor wet build temp and outdoor dry bulb temp , and reference to your superheat chart. Doing all this ensures you done your job right and your customer's happy.
Also watch out for the filter drier that's probably sitting inside the condenser.
Without some more info we're just taking wild guesses.
Go back and get more info. Even if you have to go back on your own time, go back and get more info. Take this as a learning experience.
Is the system mismatched?
We need entering and leaving evaporator dry bulb and wet bulb, outdoor dry bulb, suction pressure and line temp, liquid line pressure and line temp, airflow (static or actual CFM), amp draws, etc.
Without at least some of the above info, we can't even begin to help.
If it has a filter drier inside the condenser start there.
liquid line 8 degrees colder than ambient is a big red flag
I am returning to call in 10 minutes to gather more info
Well boys n girls I personally attended call today found the system has a txv and after running a few test it's safe to say its clogged also found no dryer installed
See I'm the owner of a Hvac company so my guys who are trained techs missed the txv told me it was a fixed orfice sorry for the miss communication I am returning in morning to recover the unit add a dryer and replace txv on system then ill pull it down to 500 microns and recharge
Thanks again
There is a drier inside the unit unless some already removed it its about 1 1/4 inch in diamater and 6 inches long and copper . also have replaced many trane txv's due to high superheat
whats the model number of the unit
unless it is a xb 300 unit it should have a drier inside they are bullet driers anyhow you are more than likely going to solve the problem by replacing the txv