- Design is Everything -
It’s time to replace your heating and/or air conditioning system. We want to help you understand the services you should expect from your heating and air conditioning contractor at change-out time.

A quality installation begins with a professional design
Unfortunately, some contractors merely size a new system based on the old system’s capacity rather than completing a professional design. What if your home’s heating and cooling needs have changed since the last system was installed many years ago? What if the original system was not sized properly to begin with? Guesswork can lead to under-sizing your new system which can reduce the comfort of your home. Even worse, over-sizing will add unnecessary expense to the job’s cost and may contribute to moisture-related problems down the line.
It takes time and expertise to complete a professional load calculation and system design. Contractors lacking in the necessary technical skills or who are just interested in making a “fast buck” may try to convince you this is not important. Would you want to ride an elevator or and airplane that was not professionally designed? Quality design is important in virtually every product we use including heating and air conditioning systems.
The Load Calculation is where it all begins
Year-round, comfort is the goal. In the summer, your air conditioning system not only cools your home’s air (sensible cooling), it removes moisture (latent cooling). In the winter, your heating system must keep you comfortable without causing high utility bills.
Make sure that your contractor uses the Manual J® residential load calculation procedure. Insist on it! Manual J is the official standard for residential load calculation and is required by many building codes around the country.

Your contractor will carefully measure your home and evaluate its levels of insulation. Windows’ sizes and quantity will be noted, levels of infiltration will be estimated and internal loads including lighting and kitchen appliances will be taken into consideration. A computerized analysis will be completed that indicates just how much heating and/or cooling capacity your new system should provide. After the installation of your new system is completed, you will receive a copy of the computerized load calculation for your records.
Selecting the right equipment
Heating and air conditioning equipment comes in many capacities, configurations and efficiencies. It’s important that your contractor selects the right equipment that will be compatible with your home’s heating and cooling needs. Once again, it’s difficult for a contractor to select the right equipment if an accurate Manual J load calculation has not been completed.

