How an HVAC Contractor Knows How Powerful an AC You Need

Air conditioner units on slabs at the side of a red brick building

Installing a new central air conditioning system into a house is a more complex process than many people realize. It isn’t as simple as picking a unit that fits inside the HVAC cabinet and sliding it into place. One of the most important decisions in an AC installation is choosing how powerful a unit the house needs for comfort.

An HVAC contractor in Harvard, MA knows how powerful an air conditioner to install through a process called “sizing.” It isn’t about the physical size of the air conditioner, but how much cooling in BTUs (British Thermal Units) it must put out in order to supply the household with sufficient cooling.

Why can’t I just get the most powerful air conditioner possible?

This is one of the pitfalls that amateur air conditioning installers fall into. “Okay, so the house needs a system with enough cooling power to keep everyone comfortable. There’s nothing wrong in erring on the side of ‘too powerful,’ because the thermostat can just be lowered.”

But there is plenty wrong with an air conditioner that is too powerful (i.e. oversized) for a home. An undersized AC won’t be able to meet the house’s comfort needs, but an oversized one will waste power and rapidly run down. If the air conditioner puts out too much cooling, it will shut off before completing a full cooling cycle, then turn back on a short time later, then shut off again, etc. This puts a huge strain on the compressor, often leading to an early failure, and causes electrical bills to skyrocket.

How a professional makes sure the AC is not too weak and not to powerful

A house needs an air conditioning system that’s balanced between too large and too small. It’s the “Goldilocks Principle”—an air conditioner that’s just right for the home. A licensed HVAC contractor finds out what “just right” is with a load calculation for the house.

A load calculation takes several factors about a house and uses them to determine how much cooling output from an AC will provide the balance of cooling and energy efficiency. Some of the factors in a load calculation include:

  • The square footage and volume of the house
  • The average number of people in the house
  • The heat given off from appliances and heat-producing lights
  • The number of windows and their facing
  • The strength of the insulation

When the calculation is finished, the HVAC contractor will have a specific answer to how powerful an AC is needed. If you hired a reliable, licensed, and experienced contractor, you can trust to their findings.

And to the rest…

Once the contractor knows how large an AC your house needs, they’ll work with you on what other features you want from the system, such as variable speed fans and multi-stage compressors. The physical installation will go fast, usually less than a day, and at the end you’ll have the right new cooling system in place.

We’re the experienced professionals you can trust for a new air conditioner! Call us today for an appointment.

Get in touch with the HVAC contractor trusted for over 30 years: Basnett Plumbing, Heating & AC.

Need HVAC Service?

Contact the experts at Basnett Plumbing, Heating, AC & Electrical.
Call us at 978-431-2906!