If you’re shopping around for a new HVAC system, it’s important to obtain a load calculation of your home from your HVAC professional so that you know the size of the system needed. This is a better method than simply purchasing a new system the same size as your old one. Accuracy is paramount for long-term energy efficiency, comfort, and system performance.

What is a load calculation?

A load calculation of your home is a measurement of the heat gain and loss which is dependent upon several factors, including:

  • Local climate
  • Home construction materials
  • Orientation to the sun
  • Square footage
  • Number of floors
  • Ceiling height
  • Number, size and type of windows
  • Location, amount and type of insulation
  • Estimate air leakage
  • Inspection of vents, ductwork design, registers and grilles
  • Occupant size, age and comfort preferences
  • Landscaping elements
  • Number and type of appliances and lighting

Load calculations and furnace sizing

The size of your furnace directly affects home comfort, energy consumption, ductwork performance and wear, and the furnace’s performance and long-term wear. If your new HVAC system is too small, it won’t be able to provide enough heat to meet your comfort preferences. The furnace will have to run for very long periods, which eventually leads to early repairs and system failure.

If the furnace is oversized, it powers on and off repeatedly. This wastes energy, significantly reduces home comfort, puts extra strain on ductwork and can even overheat the heat exchanger if hot air doesn’t circulate quickly enough through the system. The high limit safety switch shuts down the furnace in this event.

After calculating the results

Your technician can help you understand your options regarding size, efficiency and long-term performance of your new HVAC system. High-efficiency furnaces reach AFUE ratings over 98 percent. This could save as much as 50 percent in heating costs when compared to a very old furnace with an AFUE rating of 60 to 65 percent.

If you would like more information, contact Stack Heating & Cooling today. We’ve proudly provided reliable service to northeast Ohio homeowners since 1976.

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

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