First let me begin by saying I'm definitely NOT a DIY-er! Just someone who also lives in Texas (Dallas area) and has questions on AC operation and what I'm being told by my AC repair company. As a single parent I don't have time to do a lot a research so any advice/clarification you can give will be a great help!
About my system: I live in an 11 year old home. It is 1880 sq ft. The AC system is original. It is a Payne PH10JA042-C. I'm not sure of the tonnage but from what I've been able to determine from the net that Model is a 3.5 ton unit. If anyone has other information about the tonnage, please let me know.
My question is in two parts:
First, my AC went out a couple of days ago. The repair tech said the motor start capacitor in the outdoor unit had gone out and replaced it. This same part went out three months earlier in April so was covered by warranty. He said the reason the capacitor was going out was that the condenser "had a problem". He cited a strange noise which I can't really hear. He continued to say that the pressures looked good but showed me a device connected to a thick pipe going into my house. He that he said was reading the temperature of the coolant going into the house. The reading was approx 87 and he said it should be around 55 to 65. This indicated that there was a problem with the condenser and it was not working efficiently. He said the entire outdoor unit should be replaced. He also said that the inside coils should be replaced because a new type of refrigerant is required by the gov't. The repair company called later that afternoon to give me a quote that shocked me.
Here are my questions from the first part: with the capacitor replaced, my house cooled from 91 to 77 degrees from 2 pm to 10pm. How fast should the house cool? Is 8 hours what would be expected or would it be more like a couple of hours? Also if the temperature of the refrigerant is 87 degrees how would my house ever cool down to 77 degrees? That doesn't make sense to me. If I replace the outdoor unit do the inside "coils" need to be replaced as well? The quote the company gave includes a new thermostat. Why do I need to replace my thermostat when the existing one works fine?
The second part deals with how well my system is functioning. I really think alot of this is covered in the post earlier today by SWTSAE. I have a similar situation. My ac will run continuously from about noon until 10 pm. I keep it set on 78 but around 4 pm the temp will creap up to about 80 and stay there until the sun goes down. From reading the post I reference it appears that I need to take a look and the "seal" of the envelop with thing like caulking and radiant barriers. Are there reliable companies that will for fee come in and evaluate a home and make suggestions? Can anyone suggest links on the web where I might learn about this myself? Thanks to everyone who posted info in SWTSAE's question; that helped me a lot.
Also can this unit be used as a heat pump for cooling in the summer? I downloaded the manual and it says the compressor is "designed specifically for heat pump duty, with energy efficiency during heating and cooling operation." Would that be more efficient? The tech asked something about this yesterday. The thermostat (mfg Hunter but couldn't find model) has three settings: normal, heat recovery and emergency heat. In the winter I know I can use natural gas or use as a heat pump. I set it on normal to run as a heat pump and on emerg heat to use nat. gas.
Thanks in advance for any information you can share.