New HVAC System Design: Insist on Right Sizing

New HVAC System Design: Insist on Right SizingThe most important aspect of replacing an HVAC system depends on sizing it right, which is why this should be the first step in the process. Any contractor installing a cooling or heating system in your home should perform a detailed cooling or heating load calculation using Manual J software. The size and capacity of the chosen system will impact your energy bills, system performance, and the equipment’s service life, all major considerations when replacing heating and cooling equipment. 

Choosing the wrong size HVAC system will leave you with higher energy bills and accelerated wear on parts. Not all homes have the same conditioning loads, even if the floor plan and square footage is the same. The calculations should take these factor into account:

  • Square footage to condition;
  • Insulation levels in walls and attic;
  • Rates of air infiltration;
  • Quality, size and exposure of windows;
  • Floor-plan design, including number of levels;
  • Preferred indoor temperatures;
  • Household size and ages;
  • Amount of heat created indoors; and
  • Landscaping factors.

Besides being able to find the right size for the HVAC system, this exercise helps you see if you could better insulate your home, seal air leaks and upgrade inefficient windows – all steps that will allow your to reduce the size of the system you need. Smaller equipment costs less to purchase and to operate over its lifetime.

Should you skip the sizing process, you could install a system that’s too large, which may have more serious consequences than choosing one that’s too small. When a system is oversized, it runs in short cycles. HVAC equipment uses the most energy when it first starts running, and will turn on and off frequently, reducing your comfort. Oversized equipment also struggles to evenly heat a home and won’t do as good a job of air filtration or humidity control.

The ductwork needs to be included in the sizing process, as well. Manual D software works in conjunction with Manual J and will help the contractor determine the capacity and configuration for the ductwork.

For more information about sizing an HVAC system and why it’s so important, contact the experts at NisAir Air Conditioning and Heating, proudly serving homeowners in Palm Beach, Martin and Indian River counties for more than 40 years.

Our goal is to help educate our customers in Martin, Palm Beach, St. Lucie and Indian River Counties in Florida about energy and home comfort issues (specific to HVAC systems).  For more information, download our free Home Comfort Resource guide.

Image courtesy of Shutterstock

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