Ask Dirk: Are bigger systems always better?

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If you’re in the market for a new heating or cooling system, you may be tempted to go big. Whether you are replacing or upgrading your existing system or building a new home, here are a few points to keep in mind to help you steer clear of avoidable HVAC problems.
The size of your heating or cooling unit shouldn’t be determined by the cubic footage of your home or office alone.
Many factors play a role in the amount of heating or cooling your home needs. Walls, ceilings, windows, floors, and doors are the primary areas where heat is lost or gained. The orientation of the building in relation to the sun will also have an effect.
The amount and quality of insulation also plays a role along with the quality of your windows. The volume of outside air leaking into or out of an indoor space, or infiltration rate, can also impact your heating or cooling needs. If too much outside air is able to enter, your system will have to work harder.
Benefits of a properly sized system
Proper sizing lets you keep your desired temperature more precisely controlled and improves the overall efficiency of your equipment. A system that is too large will run hotter in heat mode, and colder in cooling mode. These extreme temperature swings are harder on a mechanical system than if it is running at its optimal temperature range.
When your HVAC system fires up, the motor draws more amps to come up to speed, the gas valve opens and other mechanical components are operating. Having longer run cycles without so many stops and starts reduces wear on the equipment and improves the overall efficiency.
Installing appropriately sized equipment also has the benefit of making your ducting more efficient. Existing ducts are often too small to handle oversized equipment. You can’t run a garden hose off a fire hydrant. The same principle applies when you try to cram more air through undersized ducts.
How to figure out what size system you need
A Heat Load Calculation is one of the best ways to figure out how large of a heating or cooling system a building needs and a reputable HVAC service company can help. A contractor who has done a lot of load calculations can probably provide a reasonable estimate of the size of equipment needed for your home.
Want to know more?
Helping you make the right choice when it comes to your heating and cooling systems is your HVAC professional’s job. Choosing the right system for you and your home can save you money, make you more comfortable, and help your system last longer.
If you have a question or comment, I’d love to hear from you. Please send it to me at and I’ll try to answer it in an upcoming column.
For more than 30 years, Roper’s Heating and Air Conditioning has been providing essential indoor climate management services to the citizens of western Nevada. Roper’s is a family-owned, community-oriented business that specializes in the restoration and preservation of Total Home Comfort. Roper’s Heating and Air Conditioning is located at 2062 S. Edmonds Drive in Carson City.


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