Numerous Factors Influence Your Air Conditioner Upgrade to Keep Your Home Cool This Summer
You buy shoes in the right size for your feet and sheets the right size for your bed, so it only makes sense that your air conditioner should be the right size for your home.
And although shoes and sheet sizing are a little more straightforward than HVAC equipment sizing, the way that HVAC contractors calculate the air conditioner size you need is pretty easy, too.
Keep reading to learn the answer to the commonly asked question, “What size AC unit works for my home?” Understanding this calculation will help you carefully vet new equipment estimates from HVAC contractors in Kansas City.
What Does AC Size Refer To?
When HVAC contractors talk about AC size, they’re talking about cooling capacity within the span of one hour, measured in British thermal units, or BTUs.
An air conditioning unit for your home needs about 20 BTUs of cooling capacity to cool each square foot of living space. Of course, there are other factors that can increase or reduce the BTUs required, such as if your home is heavily shaded or extremely sunny, household size, ceiling height, the age of your windows, and how well your home is insulated.
Cooling ability is also known as tons. One ton is the equivalent of 12,000 BTUs.
How to Calculate BTUs Like a Pro HVAC Contractor
First, find your home’s square footage. You can either refer to your real estate appraisal documentation, which will list square footage, or measure your home yourself, by multiplying the length of each room by its width, and adding the area of all rooms together.
Take your total square footage and multiply it by 20 to see how many BTUs you’ll need to cool your space. Reduce BTUs by 10% if your home is heavily shaded or increase it by 10% if your home gets a lot of sun.
If your ceilings are higher than 9 feet tall, add about two additional BTUs. The same applies if you know your home is poorly insulated.
For example, if you have a 2,000-square-foot home with 9-foot ceilings without any additional special considerations, you’ll need a unit with about 30,000 to 33,000 BTUs and 2.5 to 2.75 tons.
Other Considerations for Determining AC Capacity and Size
Another important measurement when calculating the size of AC you need in your house is to consider SEER ratings. SEER, which stands for Seasonal Energy Efficiency Ratio, refers to the cooling output divided by the total energy used. Basically, it is a number that represents how energy-efficient your air conditioner is. The less energy required, the higher the SEER rating.
To find the right air conditioner for your home, your HVAC contractor will calculate the number of necessary BTUs and tonnage, and then look at SEER options. As a homeowner, you can opt for a lower SEER unit, which will cost less to purchase, or you can spend more on a higher SEER unit, which will save money on energy bills over time. Your SEER rating is negotiable; AC tonnage is not.
The lowest SEER rating available for purchase is 14; the best HVAC contractors will offer you a list of options, in order of upfront cost, including nothing lower than a 14, extending into SEER ratings in the low 20s.
What Happens If I Don’t Get the Right AC Size?
If you buy an undersized central AC unit for your home, you could face the consequences. HVAC contractors near you will tell you that you’ll risk the following:
- Uncomfortable temperatures in the home. If your air conditioner is too small, it won’t be able to adequately cool your house.
- Higher humidity. Running the air conditioner in your house helps lower humidity levels, especially during muggy Kansas City summers. If your air conditioner is too small, humidity levels in your home can increase, resulting in excessive moisture, mold growth, and poor indoor air quality.
- Higher energy costs. Because your air conditioner struggles to cool your home, it will run more often and for longer to keep your house cool.
- Shorter lifespan. Because your AC unit will run more frequently, its lifespan can be shorter than expected due to overexertion. You’ll end up replacing it again and ultimately spending even more money.
If you buy a unit that is too large or powerful, you could face:
- A lack of gradual, even cooling. You may experience cold spots throughout your home.
- Too much humidity. Because oversized systems are so powerful, the dehumidification process doesn’t have enough time to take place before the AC cools the house to the temperature set on your thermostat.
- Shorter lifespan. Because your system will “short-cycle” – turning off and on in rapid succession – it can put strain on your compressor and blower fan motor, ultimately reducing its useful lifespan.
Ask a Kansas City HVAC Contractor About AC Size
Home measurements and adding or reducing BTUs based on home features is best performed by a professional, but understanding how size is calculated can help you make a more informed purchase decision.
Contact the best HVAC contractor near you for accurate size requirements and for estimates on a new air conditioner for your home.
