"Getting what you need at the outset" says California system installer Ron Hassebroc "will ensure that you don't need to purchase upgrades later on."
Hassebroc offers four factors to consider when choosing a new central air conditioning unit:
The BTU measure – The British Thermal Unit (BTU) measure affects the system's ability to cool. The higher the BTU rating the more powerful and quick the performance. The BTU measure you need is based on the size of your home it's insulation and other factors – so while a low BTU rating may not efficiently cool your home choosing the highest BTU may be a waste of money and energy. Rely on the expertise of the salesman or installer to determine the BTU measure you need.
The Seasonal-Energy Efficiency Rating – Known as the SEER rating this measure helps ensure the system will work at peak efficiency providing the best use of BTUs for the lowest price. DO look for the highest SEER rating possible – and choose an Energy Star unit since their SEER ratings are typically 14 percent higher than competing models.
Minimum Efficiency Reporting Values (MERV) – a higher MERV rating means your unit's filter works better trapping more dust and other airborne particles. Ratings are on a 1 to 12 scale. While 12 is ideal offering the best air purification on the market anything above 9 is still very clean.
Installation costs – These can vary depending upon the existing ductwork in your home and the size of the unit you have selected. Get estimates before you purchase a new unit. When factoring installation costs you may find that a seemingly more expensive model will actually cost less overall if installation is included in the price.