Homeowner's Guide For Buying Your Next Central AC

Looking to buy a new central AC for your home? Sandium's homeowner's guide provides expert advice and tips.

Updated on Oct 22, 2023
5 min read
Homeowner's Guide For Buying Your Next Central AC

It can be confusing to install a new or replace an existing central air conditioning unit. This guide contains all the facts a Bay Area homeowner would require to buy a central air conditioner. Keep reading if you want to make a poignant choice and move ahead with confidence.

Time for a Replacement or Repair?

Many homeowners are confused between paying for yet another repair or investing in a brand-new central unit. Air conditioning units are worth fixing when they are relatively new or the repair is minor. However, you should replace your existing unit if:

  • it has a declining efficiency because of huge energy bills
  • it requires costly and frequent repairs
  • it makes use of ozone-depleting effect R-22
  • it is over 10 – 15 years old

Central Air Conditioner Types

There are two basic types of central air conditioning units:


Split air conditioners have separate evaporator and condenser units. The evaporator coil is located indoors. It may include an air handler or a furnace as well. The compressor or condenser is situated outdoors in a weather-resistant metal cabinet.

Cooled air is distributed throughout the home by this type of air conditioner using the same ducts which circulate warm air from the furnace in cold season. This is a popular type of air conditioner. It is also the most economical to install in large sized homes, provided there is existing ductwork.


The condenser, evaporator and compressor are bundled in a single cabinet in packaged air conditioning units. The AC unit may also contain electric heating coils or a gas furnace. This cabinet is generally installed outdoors on a concrete slab at foundation level or on the roof. Packaged air conditioners are great space savers and preferred for smaller houses. The unit is also easier to install.

Factors to Consider

These are a few factors to consider when purchasing a central air conditioner:

Energy Efficiency

You should look at the Seasonal Energy Efficiency Ratio (SEER) rating. Higher ratings indicate a more efficient air conditioner. However, units with higher rating may also cost more. Federal standards mandate a SEER of minimum 13 for new air conditioners. Certain air conditioner units have SEER of 25 and higher while Energy Star certification is awarded at 14.5 SEER.

Multi-Zone Cooling & Heating

You can take control of your comfort by installing a central air conditioning unit with multi-zone heating and cooling. The technician can insert dampers throughout the ductwork for ensuring that every family member in your home is comfortable. This will divide your house into smaller zones, with individual thermostat that fine-tunes the temperature.

Correct Sizing

You should never indulge in guesswork when purchasing a new air conditioner. You may end up being a lot less comfortable by investing in an AC that is not correctly sized. Undersized systems may not be able to cool the entire home. Moreover, oversized systems may not properly dehumidify or short-cycle. This will eventually cause wear and tear.

BTU (British Thermal Units) is used for measuring the required AC size. Roughly, you would require 20 BTU of cooling power for every square foot. These are a few essential factors you need to consider for an accurate calculation:

  • ceiling height
  • number of stories
  • sun exposure
  • positioning of exterior doors and windows
  • usual number of occupants

Join the Future of Home Comfort

Take the first step towards comfortable, energy-efficient, and stress-free living by scheduling a consultation with Sandium.