How Do I Select the Size of My HVAC System?

San Rafael

(415) 942-6565

Santa Rosa

(707) 452-3464

One of the significant factors that will affect the efficiency of your HVAC unit is its size. An oversized system will cool and heat your home faster. However, you will have several hot and cold spots. On the other hand, an undersized unit will use more energy than usual to cool or heat your home.

Consider these factors when determining the right HVAC unit size for your home.

The Age of Your Home

If you have an old home, it may not have adequate ventilation, or the ductwork may have gone bad. It makes sense to have a technician perform a home energy audit.

Your energy audit inspector will recommend changes or improvements to accommodate a new system based on their findings. Make sure the electrical system is up to current regulation.

The Number and Condition of Windows

One of the most important factors to consider when determining the size of the HVAC unit you need is the number and condition of your windows.

Your home might be losing up to 30 percent of its heating and cooling energy through air leaks around windows and doors. If you have old windows, add weather-stripping around them to seal them effectively.

If you have single-pane windows, you may have to change them or opt for a bigger unit. Single-pane windows are not as efficient at insulating as their double and triple paned counterparts.

Home Placement

A difference of 90 degrees in your home’s placement can influence the size of the HVAC system you need. Thoughtful landscaping with the inclusion of indigenous shade trees can improve the HVAC system’s efficiency by up to 20 percent.

Sizing Your HVAC System

Step-1: Perform a Manual J Load Calculation

Have a contractor perform a Manual J Load calculation to determine the BTUs required to heat and cool your home.

A Manual J calculation for your home will factor in your property’s different characteristics such as its orientation, position of the walls, building material quality, and amount of insulation.

Step-2: Calculate the Square Footage of Your Home

You will first have to calculate the square footage of every room. A room’s square footage= its length* width. Add the square footage of every room to get the total square footage of your house.

Step-3: Calculate the Necessary BTU Output

Find your climate zone. To calculate the necessary BTU output, multiply the BTUs required per sq. ft (according to your climate zone) and your home’s total square footage area.

John Owens Services Inc. offers top-notch HVAC repair services near Novato. Our heating and cooling experts know everything there is to know about HVAC systems. We will help you select the right HVAC system size for your home as per your heating and cooling requirements. To schedule an inspection, call 707-207-8592.

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San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464



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San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464