As homes age, one of the major replacements undertaken is your HVAC system. There are a number of things to consider when replacing or upgrading your HVAC system. HVAC replacement can be a daunting and expensive task, so you should not rush into decisions that you might regret later.
Heating and cooling accounts for approximately 44 percent of your home's energy consumption. To reduce your monthly utility bill, consider choosing an HVAC system that is as efficient as possible within your budgetary constraints. The following resources will help:
- Best Practices Guide for residential HVAC retrofits. U.S. Department of Energy.
When selecting a new air conditioning unit there are two major factors to consider: efficiency and size. To determine the efficiency of an air conditioner look for its SEER (Seasonal Energy Efficiency Ratio) rating. The higher the SEER rating the more efficient the unit, with SEER 12 or above being considered energy efficient. National data shows that you can save $121/year by replacing a SEER 8 unit with a SEER 13.
The second factor to look at is size, generally listed in tons. People commonly install a bigger unit than is required to cool your space thinking that it must cool better. This, unfortunately, is not necessarily the case. When a unit is oversized it tends to cycle more and thus be less energy-efficient. Oversizing may only cost you an additional $10/year in utility costs, but the correct, smaller unit should cost less to purchase.
Your HVAC system is only as good as the ducts that deliver the warm or cool air to the living spaces. Many existing home's air ducts are prone to leaks, allowing conditioned (heated or cooled) air to escape into the attic, crawl space, or basement. Sealing ducts will make your system more efficient by preventing that air from escaping. Current California energy code requires ducts be sealed and tested, in new construction, to allow between 5 to 12% leakage, depending on the specific application. The code also requires sealing and leakage testing when parts of the duct system are changed or expanded.
Current California energy code also requires insulating ducts to prevent heat loss or gain, as it is very inefficient to move conditioned air through ducting without insulation.
- California Energy Code (CCR Title 24, part 6, subchapter 7)
As homes become better sealed to prevent air leakage (drafts), they also become less efficient at providing adequate ventilation. Ventilation is important, as fresh air needs to be brought into your home to replace the exhaled carbon dioxide. Ventilation is also very important to reduce the concentration of toxic chemicals that are present in many building and consumer products. Ventilation can also reduce the risk of mold or mildew growth when moisture is "trapped" inside of a tightly sealed home.
Utility Rebate Programs
Many utility companies offer various rebate programs for energy-efficient HVAC components as well as other energy-efficiency measures.