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Manual J: Why Your Contractor Should Know It Chapter And Verse

When it comes to home heating and air conditioning equipment, size does matter.

If you want to be comfortable in your own home, and spend as little as possible on your heating and cooling bills, you’ll want to have HVAC equipment that’s the perfect size for your needs. Improperly sized equipment can cause many problems, such as:

  • High utility bills
  • High humidity
  • Poor indoor air quality
  • Wide temperature swings
  • The inability to fully warm up or cool down your home
  • Excessive wear and tear on the equipment itself, leading to extra repairs and more frequent replacement

To avoid these problems, you don’t want to select an air conditioner or furnace until your HVAC contractor calculates the exact amount of heating or cooling power your home requires. A professional contractor will do so by utilizing a handbook known as “Manual J.”

Manual J gives detailed instructions and charts to determine the amount of heat that a home loses on a cold winter day, or the amount of heat it gains during the hottest part of summer. Performing such a calculation requires a manual because of the many factors involved. For example, heat loss or gain is influenced by:

  • Insulation levels
  • The number of people in the house
  • The number of windows
  • The type of windows
  • The direction the windows face
  • Total surface area of the house
  • Location
  • Shade from trees or other buildings

Manual J explains how to calculate the way that each of those variables affect the amount of heating or air conditioning required. With an accurate calculation, the HVAC contractor can recommend the right furnace or air conditioner to install. In doing so, the contractor will be saving you money, both today (by not spending extra on a system that’s unnecessarily large) and throughout the life of the system (by minimizing energy costs and future repair bills).

If you live in the Metro-East area and need new HVAC equipment installed, please contact the Manual J experts at Ernst Heating & Cooling. We’ll make sure you get a system that’s the perfect fit for your home.

Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems).  For more information about Manual J and other HVAC topics, download our free Home Comfort Resource guide.

Ernst Heating & Cooling services Hamel, Illinois and the surrounding areas. Visit our website to see our special offers and get started today!     

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