The most important factor when purchasing any HVAC equipment is to make sure that it is sized correctly.
When a home is well-insulated and properly air-sealed, a smaller system is usually recommended. When your home is leaky and your ducts are leaky, you do need a larger system to keep your home comfortable. But a larger system costs more money upfront and to operate. Why buy a high-efficiency system if it is being wasted through gaps and duct leakage?
Here are my recommendations:
- Have a blower-door and duct-blaster test performed (energy audit).
- If needed, upgrade the envelope of the house and the ducts, then test for combustion safety.
- Purchase an A/C that is the right size for your well-sealed home. Larger systems can short-cycle, which affects efficiency, comfort and durability.
- A 14 SEER Energy Star rating is the minimum and if designed and installed correctly will be just fine. Make sure that your HVAC contractor understands efficiency and that a duct-blaster test is performed post-installation. If the ducts are brand new a minimum of 3% duct leakage is acceptable.
If the envelope and ducts are tight and the system is designed for a balanced air flow, a 2,000 sq. ft. home can be comfortable with a 2-ton system.
The FREUS is a watercooled condensing unit with a good EER rating -- check it out.
If you get a chance, let me know how it goes.