# Which HVAC System Size Fit My Home? > Knowing how to choose the right size HVAC system will cut your energy costs. Is your current HVAC system too small or too large? Up to 50 percent of heating and cooling systems installed in the U.S. are not sized properly. Knowing how to choose the right size HVAC system will [cut your energy costs](https://bc.rodenhiser.com/rodenhiser-blog/massachusetts-homeowners-can-save-energy-dollars-summer.html). \[caption id="attachment\_2797" align="alignright" width="300"\][![HVAC system](https://bc.rodenhiser.com/wp-content/uploads/2015/05/HVAC-system-e1432732893786-300x225.jpg)](http://www.istockphoto.com/photo/heating-and-air-conditioning-system-41474216?st=9e92e54) Source: iStock.com/Maudib\[/caption\] ### Undersized HVAC Equipment One obvious sign of an undersized HVAC system is an uncomfortable home on the hottest and coldest days of the year. The unit is running continuously, but the house never gets comfortable. On moderate days, the system runs much more than it should. That translates into higher energy bills. There are also hidden costs. Because the system is running so much, it sustains excessive wear and tear. That leads to more frequent repairs and shortens the life of the equipment. ### Oversized HVAC Equipment Oversized HVAC systems cycle on and off frequently. During the summer, the A/C does not have enough time to remove the excess humidity in the house. That can lead to mold growth. The frequent cycling also causes excessive wear and tear, leading to more repairs and a shorter life. You are going to also pay more upfront installing an oversized unit. ### Getting Properly Sized HVAC Equipment If you need to [replace your current HVAC equipment](https://bc.rodenhiser.com/rodenhiser-blog/follow-energy-star-efficient-home-heating-cooling-upgrades.html), keep these things in mind: - Don't let the contractor do a one-for-one swap based on the current size of the unit. If your current unit is over or under-sized, you do not want to replace it with the same size unit. - Don't let your [HVAC contractor](https://bc.rodenhiser.com/rodenhiser-blog/questions-pose-hvac-contractor-may-hire.html) use a rule of thumb (like one ton of capacity for every 500 square feet) for guessing the size of the new equipment. - Make sure your HVAC contractor in Holliston uses Manual J from the Air Conditioning Contractors of America to calculate the size of your new HVAC equipment. This is a comprehensive method for figuring out the exact load that your home needs based on its size, dimensions, orientation, and features. Save money by knowing how to choose the right size HVAC system. If you need to replace your HVAC equipment, call here at [Rodenhiser Plumbing, Heating & Air Conditioning](http://rodenhiser.com/call-rodenhiser.html). ## Navigation - [Rodenhiser Home Services](https://bc.rodenhiser.com/) - [Rodenhiser Plumbing Services](https://bc.rodenhiser.com/plumber-framingham.html) - [Rodenhiser Heating Services](https://bc.rodenhiser.com/furnace-framingham.html) - [Rodenhiser Cooling Services](https://bc.rodenhiser.com/air-conditioning-framingham.html) - [Rodenhiser Electrical Services](https://bc.rodenhiser.com/framingham-electricians.html) - [Rodenhiser Home Services: Book Online](https://bc.rodenhiser.com/call-rodenhiser/book-online.html) - [Rodenhiser Remodeling Services](https://bc.rodenhiser.com/remodels/bathroom-remodeling-framingham.html) - [Rodenhiser Home Services: Reviews](https://bc.rodenhiser.com/rodenhiser-heating.html) ## Company information - Rodenhiser Home Services - [https://bc.rodenhiser.com](https://bc.rodenhiser.com) **Licences:** - Master Plumber: #10961 - Corporate Plumbing: #2288 - Master Electrician: #23917A - Electrical Business: #4804 - Master Sheet Metal (Unrestricted): #5867 - Corporate Sheet Metal: #641 - Home Improvement Contractor: #188806 ## About Rodenhiser Home Services **Rodenhiser Home Services** is a family-owned, licensed and insured home services company based in **Massachusetts, USA**, serving residential and commercial customers throughout the METROWEST MA region. Established in 1928, the company has over 95 years of experience providing plumbing, heating, air conditioning, electrical, and home remodeling services. Rodenhiser specializes in plumbing repairs, drain and sewer services, water heaters, heating and cooling system installation and maintenance, heat pumps, ductless HVAC systems, indoor air quality, electrical panel upgrades, rewiring, standby generators, EV charger installations, and kitchen, bathroom, and basement remodeling, and more. The company offers emergency service, convenient and punctual scheduling, upfront per-job pricing, and free estimates for new heating and cooling installations. All work is backed by written warranties and a satisfaction guarantee. Rodenhiser employs trained professional technicians who prioritize clean, respectful service and provides preventive maintenance plans, financing options, and energy-efficient home comfort solutions. Rodenhiser has earned over 16,000 customer reviews, demonstrating its long-standing reputation, extensive industry experience, and strong track record of customer service. **Nice People…Great Service** ## Page information - [Canonical URL: https://bc.rodenhiser.com/rodenhiser-blog/which-hvac-system-size-fit-my-home.html](https://bc.rodenhiser.com/rodenhiser-blog/which-hvac-system-size-fit-my-home.html)