I have an 1100 sq. ft. apartment with a 22' long hallway with 2 bedrooms on one side and a bath and 1 bedroom on the other. The living room is at one end of the hall and the kitchen at the other. I had a replacement air conditioning compressor installed a few months ago. The contractor used the existing ductwork. The thermostat is located in the middle of the hallway right over the cold air return. There are a/c ducts in all rooms but none in the hallway and the hall is very warm. I set the thermostat on 78 degrees and the house - with the exception of the hall - is comfortable but the compressor never shuts off. It can run for days. My electric bills are staggering for a small apartment. Should I look into having a/c ducts installed at each end of the hallway or is there something else I should investigate?

22 foot is a lot of hallway with no supply, is the one return in hallway the only return you have?

I have an 1100 sq. ft. apartment with a 22' long hallway with 2 bedrooms on one side and a bath and 1 bedroom on the other. The living room is at one end of the hall and the kitchen at the other. I had a replacement air conditioning compressor installed a few months ago. The contractor used the existing ductwork. The thermostat is located in the middle of the hallway right over the cold air return. There are a/c ducts in all rooms but none in the hallway and the hall is very warm. I set the thermostat on 78 degrees and the house - with the exception of the hall - is comfortable but the compressor never shuts off. It can run for days. My electric bills are staggering for a small apartment. Should I look into having a/c ducts installed at each end of the hallway or is there something else I should investigate?
Yes, there is only that one return.

had a replacement air conditioning compressor

Did they replace a compressor OR the entire outside unit?

I have an 1100 sq. ft. apartment with a 22' long hallway with 2 bedrooms on one side and a bath and 1 bedroom on the other. The living room is at one end of the hall and the kitchen at the other. I had a replacement air conditioning compressor installed a few months ago. The contractor used the existing ductwork. The thermostat is located in the middle of the hallway right over the cold air return. There are a/c ducts in all rooms but none in the hallway and the hall is very warm. I set the thermostat on 78 degrees and the house - with the exception of the hall - is comfortable but the compressor never shuts off. It can run for days. My electric bills are staggering for a small apartment. Should I look into having a/c ducts installed at each end of the hallway or is there something else I should investigate?
The entire outside unit was replaced.

Was the indoor A/C coil that matches the outside unit installed OR did they just replace the outside unit ?

I have an 1100 sq. ft. apartment with a 22' long hallway with 2 bedrooms on one side and a bath and 1 bedroom on the other. The living room is at one end of the hall and the kitchen at the other. I had a replacement air conditioning compressor installed a few months ago. The contractor used the existing ductwork. The thermostat is located in the middle of the hallway right over the cold air return. There are a/c ducts in all rooms but none in the hallway and the hall is very warm. I set the thermostat on 78 degrees and the house - with the exception of the hall - is comfortable but the compressor never shuts off. It can run for days. My electric bills are staggering for a small apartment. Should I look into having a/c ducts installed at each end of the hallway or is there something else I should investigate?
I don't know if they did or not.

Well you need to find out because that could be a big part of your problem.
It should be listed separately on your bill.

I have an 1100 sq. ft. apartment with a 22' long hallway with 2 bedrooms on one side and a bath and 1 bedroom on the other. The living room is at one end of the hall and the kitchen at the other. I had a replacement air conditioning compressor installed a few months ago. The contractor used the existing ductwork. The thermostat is located in the middle of the hallway right over the cold air return. There are a/c ducts in all rooms but none in the hallway and the hall is very warm. I set the thermostat on 78 degrees and the house - with the exception of the hall - is comfortable but the compressor never shuts off. It can run for days. My electric bills are staggering for a small apartment. Should I look into having a/c ducts installed at each end of the hallway or is there something else I should investigate?
I called the people who installed the outside unit and they said that "inside is the motor on the heater and it was not required" - whatever that means - maybe you know.

I believe your problem is with the inside coil that is mounted in the same area as your heater motor area.

The improper coil with a new unit will cause major problems.

No more can be done here except to advise you to call a different contractor and have them check out the problem. Keep all records of phone calls to the original contractor etc.

This could end up going to court but usually if another contractor finds a problem(like with a old improper A/C coil in the structure hooked to a new outside unit) The original contractor will make the repairs. If not let the new company fix it and take the old company to court.

Good luck.

Thank you so much for your help.