Heat Pump Compressor failed and looking for a replacement system.

Our House is 13 years old and the heating system is a Bryant heat pump with propane backup. The heat pump compressor failed and it would cost $1500 to replace the compressor. The tech that diagnosed the system recommended replacing the entire system.

We live in southeastern Pennsylvania. The house is a 2 story frame construction with vinyl siding. There is a full basement and roughly half of the basement is out of the ground. There is a large sliding glass door entrance in the back of the basement. 60% of the basement is finished and we use it as an office and work from home.

The current system has a 2.5 ton heat pump and a 66000 BTUH furnace. We have lived with this system for 13 years, but there a number of issues we would like to improve:

1. Cost to operate our heating and especially our AC bills($400/Month in July and August) seem high.

2. 2nd floor is not comfortable in the summer

3. 1 Bedroom (the furthest duct run) does not heat or cool well

4. Basement office is not comfortable in summer

The basement does have about 6600 BTUH of computer equipment running.

There are currently no ducts or returns in the basement office.

We would like to add a duct and a return to the office

5. In the winter we have problems with low humidity

6. We would like to reduce the dust, etc in the air flow

7. At best the existing systems seems to not do a good job removing humidity

We have 4 quotes from HVAC companies and they vary a lot.

2.5, 3.0, and 3.5 Ton heat Pumps

Single stage and dual stage(the 3 ton)

Standard and dual stage(with and without variable speed blower) furnace. From 66000 to 110000 BTUH

We are leaning towards the Carrier Infinity 80 Furnace with the Infinity 16 Heat pump with Infinity controls. The carrier vendor insists this will solve our problems with the second floor cooling and heating. Another vendor insists that anything but a standard speed system will make the problem worse. The vendor who is insisting the variable speed system will not work, tested our ducts with a Volometer?, but has not shared the results with us. It is likely we have a return or 2 on the second floor with problems. We are unsure about the high efficiency furnaces?

Some of the vendors measured the rooms and counted windows, but no one was sharing results with us. Subsequently, I purchased HVAC Calc and ran the Manual J Calculations myself.

Here are my results:

Without Basement: 1492 SQ FT, Sensible Gain: 19067, Latent Gain: 4562, Total Gain: 23629, Total Heat Loss: 28835

Seems to indicate a 2 TON heat pump and ( if I upsize the heat loss by 25%) a 45000 BTUH (80% AFLUE) furnace.

With Basement Office Only: 1968 SQ FT, Sensible Gain: 28634, Latent Gain: 5403, Total Gain: 34037, Total Heat Loss: 33823

Seems to indicate a 3 TON heat pump and ( if I upsize the heat loss by 25%) a 52800 BTUH (80% AFLUE) furnace.

With Entire Basement: 21844 SQ FT, Sensible Gain: 29152, Latent Gain: 5693, Total Gain: 34845, Total Heat Loss: 36528

Seems to indicate a 3 TON heat pump and ( if I upsize the heat loss by 25%) a 57000 BTUH (80% AFLUE) furnace.

I would appreciate any opinions and recommendations about improving our system, especially a standard system versus a dual stage heat pump with variable speed blower. Should we include the basement in the calculations?

Thanks,

John