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Choosing the Right Air Conditioner Size for Your House

While debunking the most common myths revolving around air conditioners, experts touch on going bigger, which is often misunderstood as the better choice. Contrary to common belief, undersized or oversized air conditioning units are both detrimental to your unit’s efficiency, life expectancy, and overall performance.

So, are you looking to replace or install a new AC? What size should you go for? And what is this HVAC sizing that technicians keep mentioning?


What is HVAC sizing?

Proper system sizing involves a lot of science and calculations that HVAC technicians use to select the right AC for your home. Proper system sizing ensures optimal unit performance.

What factors determine the right size of AC for your home?

Knowing your home’s size is paramount

This is probably the most straightforward factor. Experts will suggest that you calculate the amount of square footage in your home, which helps determine the right air conditioner size that best suits it. AC manufacturers use British Thermal Units (BTUs) as a measure for cooling capacity. On average, experts recommend about 5000 BTUs for rooms ranging from 0 to 150 square feet. 6000 BTUs will serve rooms measuring anywhere above 150 to 200 square feet, and so on. Most technicians recommend allocating 25 BTUs to every square foot to arrive at the minimum BTU AC unit you should buy.

Special and professional guidance from an expert will help you arrive at the perfect recommendation. You might get tempted and under-allocate or over-allocate the BTU units, but keep in mind; smaller BTU units will struggle to reach your home’s cooling needs, causing an increase in your electricity needs and insufficient cooling of your home. Larger BTU units run for short cycles causing inefficiency and energy wastage.

Do you have existing roof insulation?

Roof insulation has a huge impact on the size of the air conditioner you choose for your home’s needs. Houses with insulation require less cooling capacity compared to units with no insulation. Excellent insulation prevents air to escape, which improves your air conditioners cooling efforts. You can easily get away with a smaller AC and enjoy maximum cooling efforts when you have good roofing insulation.

Your current location

How’s the climate in your current location? If you live in a desert, you will probably use a bigger air conditioning unit compared to someone living in a relatively cooler place. But how do you arrive at the perfect size? Your technician will help you find the best location for the AC and determine the perfect size for your home’s cooling needs.

Extra pro tips for finding the right size of AC for your home

Make use of the Manual-J technique

For the average individual, this might sound a little technical. A good technician won’t just take a look at your house and say, “Yes, you need a 4-ton air conditioning unit.” It certainly doesn’t work like that. Ask your HVAC technician to conduct a comprehensive Manual-J for your house. Good technicians will ask about your insulation, dig their heads into the attic, count the number of windows in your house, and calculate the exact number of BTUs you need to cool your home sufficiently.

Consider SEER ratings

While focusing on the right AC size for your home, factor in energy efficiency for optimal results. The higher the SEER ratings, the better.

Maintenance is paramount

No amount of proper AC sizing outruns routine maintenance and timely AC repair. Don’t forget to take care of your air conditioning unit for extended services.

We hope that this piece shines a light on choosing the right size of the air conditioning unit. For more information, Contact Spartan Plumbing to talk to an experienced HVAC technician. We are here to help you!