Sizing Up AC Systems
Two-thirds of Florida homes' electrical usage is air conditioning. According to a recent study, more than 70% of AC systems are the wrong size or are improperly installed, resulting in extra expense and energy inefficiencies. John Crane, owner of Krauss & Crane, Inc., an industry leader in residential and commercial air conditioning systems, explains how a properly sized and installed system can lead to maximum energy efficiency, comfort and savings.

How do I know what size system to install in my home?
The 'rule of thumb' of '5 tons per 2500 square feet' to calculate AC units is long gone. Today, your AC vendor needs a computer and a measuring tape. Calculating the right size takes multiple factors into consideration including the home's orientation to sun and shade, insulation values, and the average solar heat gain in each room. Certified AC contractors will calculate the proper size system based on room-by-room cooling loads with the ACCA's (Air Conditioning Contractors of America) Manual J-Residential Load Calculation. Consider that five homes of equal square footage with varying windows, sun exposure and overhangs will likely need different size units.

Comfort is important to me. Shouldn't I just install a bigger system?
An AC unit provides comfort in two ways: cool air and reduced humidity. An oversize system will cool your home faster, but in order to dehumidify, moisture needs to condense on the evaporator coil. Large systems cool the air so quickly there isn't enough time for moisture to evaporate. In addition, larger units run many short cycles, starting and stopping more frequently, making them less efficient because start-up is the least efficient cycle.

The misconception that "bigger is better" has resulted in 2/3 of all installed residential units being too large. Smaller systems actually use less energy and remove more moisture. A system that is properly sized for your home can result in energy savings of up to 30%. At an installed cost of approximately $1,000 per ton, savings are both up front and over time.

What should maintenance include?
Professionals should check refrigeration level, airflow and duct systems during regular system servicing. If the refrigerant level is too low or high, your system is losing its ability to cool and could stop cooling altogether. The speed and volume of air moving through the system should be tested to ensure proper cooling and dehumidifying. Duct systems should be inspected for proper insulation, leaks and adequate return air.

What are some tips for finding a reliable air conditioning contractor?
Improper installation of a system can increase monthly utility bills. Make sure any contractor you hire is trained, certified, licensed and insured. Ask if they use Manual J to determine the proper size system. Do they guarantee their work? How long have they been in business? Always ask for references.

In addition to having the right size system, what are other ways I can reduce my cooling costs?
Make sure your walls and ceilings are well insulated and that windows and doors are properly sealed. Reduce heat gain by installing tinted windows or by applying window film. Insulate the ductwork in your AC system and install programmable thermostats.

For 51 years,Krauss & Crane, Inc. 772.287.1227, has built its industry-leading reputation installing state-of the-art, energy-efficient and reliable air conditioning and air filtration systems. The original dealer in Florida of TRANE, Krauss & Crane's family run operation generates long-term customer relationships.All technicians are certified by North American Technician Excellence (NATE). Krauss & Crane is a member of www.ReferredHomeServices.com, a website of respected, experienced, dependable businesses who meet or exceed RHS's rigorous review process which requires proof of proper licensing, certifications, insurance and ten verified customer references. Referred Home Services, 561-401-4004, www.ReferredHomeServices.com.