How to Find the Right Size HVAC System for Your House

How to Find the Right Size HVAC System for Your House

If you’re in the market for a new furnace, you may be trying to determine how to find the right size HVAC system for your house.

Finding the right size HVAC system for your home is crucial because it is maintaining your family’s comfort and safety, while it can also help you save on your energy bill.

Here are some tips for finding the size that’s right for your home.

How to Find the Right Size HVAC System for Your HouseFind your home’s square footage

If you don’t know the square footage of your home, this will be an important factor. You can find your home’s square footage by searching property records like your annual property tax assessment or closing paperwork.

If you cannot locate it or want to find this number yourself, you can sketch out a floor plan of your home and draw in each living space. This will not include the garage or other spaces outside. After drawing the floor plan, you can divide the home into rectangular spaces. Then, measure each of these rectangular spaces, rounding off your measurements to the nearest 0.5 foot.

Multiply each rectangle’s length by its width to calculate the area in square feet, then write this number down into the corresponding rectangle on your sketched out floor plan. Lastly, add up the total of each rectangular area of square footage you measured. This will provide you with a rough estimate on your home’s square footage.

Determine the base BTU

BTU stands for British Thermal Unit. A BTU is a unit of heat, and this will determine the amount of heat it will take to raise the temperature.

To determine the BTU needed for your HVAC system, you will want to use the home’s square footage and multiply by that number by 20. This number will tell you how many BTUs are needed to heat the space.

Here is a quick guide:

1,000 square feet x 20 = 20,000 BTUs

1,500 square feet x 20 = 30,000 BTUs

2,000 square feet x 20 = 40,000 BTUs

2,500 square feet x 20 = 50,000 BTUs

In short, taking the square footage of the living space of a home and multiplying by 20 is factoring in not only the length and width of the room but the BTUs needed to heat for the height of the room, as well. One other factor to consider is in a home with high ceilings, additional BTUs will be necessary to heat the additional volume of that added space.

While calculating the needed size of a new HVAC system may seem like “bigger is better”, the fact is an oversized system will reduce efficiency, cause increased wear on the equipment, and increase indoor humidity, according to

Decide which unit to buy

Once you have made some key calculations, such as your home’s square footage and BTUs needed, you are ready to evaluate which unit to buy.

Here are some additional factors to consider:

  • Home comfort and air quality: Some HVAC systems have additional filtration systems such as UV light, which can increase air quality and reduce allergens in the air.
  • Energy efficiency: Locate the energy efficiency rating of the system. The better the rating, the lower your energy costs over the life of the system. You can look up energy efficiency ratings at Energy Star.
  • Capacity: This is determined by the key calculations done above, including square footage and BTUs.
  • Programmable Thermostat Compatibility: If you use a smart thermostat or other programmable thermostat, ensure your thermostat is compatible with the new system.
  • Maintenance Requirements: Some HVAC systems require more maintenance than others, looking at maintenance requirements ahead of time can save you money.
  • Noise/Sound: All systems make noise when they are running. Determining where to put the system based on your noise tolerance will save frustration later.
  • Price: Saving money now may cost you money later. Calculate the cost savings of higher energy efficiency and weigh out the cost-benefit before making a final decision.

Hopefully, this information has helped you with how to find the right size HVAC system for your house.

If you would like professional input with sizing your HVAC system, we are happy to help at Pilchuck Heating.

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