I am about to replace my water to air heat pump. I have many questions and options. Any help would be greatly appreciated.
So here is my story. I have a 2000 sq ft house in central FL. It presently has a 20+ year old 2 ton Marvair water to air heat pump in the attic. We never used it too much over the last 17 years in the house. I want to replace it with a regular air conditioner that is efficient enough to use it.
Ive been working on car air conditioners for years. I got EPA certified and bought a recycling machine. I have way too may tools so I could install it myself.
I just had an estimate for a Bryant 15 SEER puron system to be installed by a very nice company.
I had bought a used 3 ton 10 SEER system to install myself as a sort of test to see if 3 tons was sufficient. The base part of the house was 1400 sq ft. The 2 ton was probably great for it. A 600 sq ft addition was put on with lots of windows. The 2 ton barely keeps up and runs almost continuously.
I need to install the line set if I install it myself but what size? The run will be 65 feet. The final system will be between 3 and 4 ton.
So the first question is what size unit? I was originally thinking 3 or 3.5 ton. The pro thought it better to go to 4 ton. Im afraid that it may be too big since we rarely cool the house below 80. I do like the idea of being able to cool the house quickly so if visitors show up we turn it on and keep them comfortable.
Should I just go ahead and pay the $50 to get the one time heat load calc program and figure the size unit needed? Any ball park estimate for a 2000 sq ft house in central FL? It is a frame house with 19 single pane windows but I have awnings to keep out the sun. The program looked complex but it may be worth it since this is a rather large investment.
If I install the used unit, will the line set need to be replaced when I put in the new, efficient system? With that long run, I was thinking of using 3/8 and 1 ¼. Do the new puron systems use smaller suction lines? I saw a chart that cautioned about too small a line and the 65 feet is rather long.
I know I should probably let the pro put in the nice 4 ton Bryant but Ive got all these tools.
Any insight would be greatly appreciated.