Installing a New AC Unit? Lower Your Cooling Load First

Published on: July 31, 2012

When preparing for a new AC unit, your air conditioning installation technician will likely calculate the cooling load for your home. The cooling load calculation actually consists of two readings of cooling load:

– The Sensible Cooling Load
– The Latent Cooling Load

The sensible cooling load is measured by taking the dry bulb temperature and the latent cooling load is measured by taking the wet bulb temperature. When you have an annual AC tune-up, the HVAC systems technician will often take these temperatures using a special thermometer. Next, the technician will estimate the cooling load of the home using a formula or table.

The sensible cooling load may be affected by several factors that you can control. You can actually lower the sensible cooling load of the home prior to your new air conditioning installation. In addition, a few changes in behavior will reduce the cooling load after the air conditioning installation.

1.) Cover glass doors and windows that face the sun.

Direct sunlight shining into the home increases the cooling load. Cover glass windows and doors with blinds or curtains. Another option is to install dark screens or reflective film on the windows that take in heat when the sun is rising and setting.

2.) Cover skylights with reflective film.

Skylights are another way that direct sunlight may heat a room. Cover skylights with reflective film to reduce the amount of heat generated by direct sunlight that enters the home.

3.) Attic insulation will lower your home’s cooling load.

Blown-in attic insulation will create a barrier that will keep the cooled air inside the living space and reduce the conditioned air that escapes through the attic. The more conditioned air that stays in the living space, the less your air conditioner will run to keep the home cool.

4.) Replace single-pane windows with double-pane, energy efficient windows.

Single-pane windows loose conditioned air at a much higher rate than double-pane windows. Double-pane windows will reduce the cooling load in preparation for your new air conditioning installation.

5.) Insulate and seal the ductwork throughout your home.

Leaking ductwork looses conditioned air and forces HVAC systems to work harder to cool the home. Inspect the ductwork for leaks and cracks. Ductwork in newer homes may be constructed of plastic and mylar. If your ductwork is made of plastic and mylar, the life of the duct system is approximately 15 years. Older homes may have ductwork constructed of metallic tubing. The metallic tubing may become bent or cracked, too. Inspect the ductwork for any bends or cracks and take measures to seal any leaks.

Insulating the ductwork will keep the conditioned air cool while the air travels from the HVAC system to the living space. When conditioned air travels from HVAC systems into rooms, the air tends to warm in transit. Insulating the ductwork will keep cool air cool as it travels from the AC system into the various rooms in the living space.

6.) Apply weather stripping around all windows and doors.

HVAC systems must work much harder to cool a home where conditioned air is leaking from around window and door frames. Weather stripping adds an additional sealing barrier around window and door frames to keep cool air inside the home. As cooled air stays in the home longer and the cooling load is reduced, your HVAC system works less to keep the home cool. This means that the HVAC system is more energy efficient and costs you less money in energy costs.

7.) Use fans throughout the home.

Ceiling fans and box fans strategically placed throughout the home will reduce the AC system’s cooling load and save energy. Ceiling fans create a breeze and move the cooled air throughout the home.

8.) Commit to regular, preventative maintenance for your new air conditioning installation.

With your new air conditioning installation, you will receive a warranty. The warranties for most HVAC systems require that the owner regularly maintain the unit. Annual preventative maintenance may be necessary to keep your warranty intact. Be sure to check the terms of the warranty. However, annual preventative maintenance is a necessary task even for HVAC systems that are no longer under factory warranty.

9.) Reduce the amount of heat that is generated in the living space by limiting your use of standard incandescent bulbs and turning lights low or off.

You may install dimmer switches to lower lighting in the home or install CFLs in place of incandescent bulbs. Incandescent bulbs generate a considerable amount of heat that contributes to the cooling load of your home. Make your home more energy efficient by reducing the amount of heat that is generated by the lighting in your home. CFL bulbs are a more energy efficient choice than conventional incandescent bulbs. Also, CFL lights give off less heat and reduce the cooling load, making your HVAC system more energy efficient, as well.