When searching for a new furnace, you don’t simply go to the nearest appliance store to pick one. It is important to get the right size to meet your household heating needs while effectively managing energy bills. We recommend you get in touch with experienced HVAC technicians to help with furnace selection and installation.
What Happens If You Get the Wrong Size Furnace?
You’ll be looking for a slew of problems if you get the wrong sized furnace for your home. It will be challenging to escape chilly weather in winter, and your power bills might reach unmanageable levels. Did you know that a poorly heated home is dangerous for your family? Frozen pipes can burst, and the cold environment may cause health issues. Do not assume an oversized furnace will keep you warmer. On the contrary, it comes with disadvantages such as:
- Premature failure due to constant cycling
- Uneven heat distribution
- Less energy efficiency
- Requires frequent repairs
What if you get an undersized furnace? You’re likely to face these troubles:
- Cold indoors in winter
- Non-stop operation, increasing energy bills
- Wears out sooner
- Uneven heating
Beyer Air Conditioning & Heating has helped thousands of homeowners and business owners set up the right size furnace. To achieve efficient heating, we can help you answer these questions.
What’s Your Home Size?
The size of your home is measured in square footage. You’ll find this information on your closing document, property tax statement, or home’s blueprint. If you don’t have the figures, you can measure the square footage in simple steps:
- Use a tape measure to take the length and width of each floor.
- Multiply the length by the width, then add up the products to get the total square footage of your house.
- Exclude rooms that are not connected to the heating system, e.g., the garage.
Furnace capacities are calibrated in British Thermal Units or BTUs. The units represent how much power it takes to heat one pound of water by one degree. When it comes to getting the right furnace size, the general rule is 20 BTUs per square foot.
In What Climate Zone are You?
When shopping for a new furnace, you need to consider the heating BTU requirements for your climatic zone. There are eight climate zones in the US according to the International Energy Conservation Code or IECC. The BTU guidelines per square foot for the first five climatic zones are as follows.
- Zone 1: 30 to 35 BTUs
- Zone 2: 35 to 40 BTUs
- Zone 3: 40 to 45 BTUs
- Zone 4: 45 to 50 BTUs
- Zone 5: 50 to 60 BTUs
The colder the environment, the more heat your house needs to stay warm. Texas experiences temperate weather in most cities. Winter in San Antonio is usually mild, so you’ll be turning on your furnace occasionally. However, Swisher County homes will need a higher BTU rating because this area experiences freezing winters.
A heating BTU or furnace calculator can help you quickly determine how many BTUs per square foot your house needs. Here is how to get the overall heat output to warm your house effectively.
Household square footage x Climatic zone BTU heating factor = Total BTU output
Is Your House Well Insulated?
While insulation is often overlooked, it plays a vital role when it comes to sizing a furnace. Proper insulation yields low power bills because it reduces the workload of your heating system. On the other hand, a poorly-insulated home leaks warm air, forcing the furnace to generate more heat to reach your desired indoor temperature.
The number of windows and the home’s age can affect the quality of insulation. Newer homes have fewer potential loopholes for heat loss. If you just bought a house with modern insulation, you can apply the lower range for heating zone requirements. Consider the higher BTU range for an older home with inadequate insulation or windows with broken seals. If you live in a two-story house, the second floor enhances insulation. So, you might need slightly lower BTUs per sq. ft. No matter your housing conditions, it is imperative to consult an HVAC expert when choosing a furnace.
What Is the Efficiency Rating of the Furnace?
In addition to the input rating in BTUs, furnaces have an efficiency rating. It is a representation of how effectively the equipment blows hot air. The minimum efficiency rating for a gas furnace as recommended by the EPA is 78%. However, today’s high-end models boast up to 98% in AFUE ratings. An efficient furnace outputs more BTUs than a less efficient model with a similar BTU input rating. The actual BTU output is calculated as:
BTU input x Efficiency rating/100
Take, for instance, an 80,000 BTU furnace with an efficiency rating of 85%. Its actual output will be:
80,000 x 85/100 = 68,000 BTUs
Note that a furnace’s heating efficiency declines over time, depending on usage. This means the equipment will produce low BTUs of heat as it approaches the end of its lifecycle. We recommend regular maintenance to fix minor issues and ensure peak efficiency. Neglecting routine services like changing filters and cleaning blockages could cost you a fortune in the future.
Is Your Furnace Too Large or Too Small for Your Home?
We’ve seen all kinds of installation mistakes for over 40 combined years of experience installing, maintaining, and repairing furnaces. Wrong-sized furnaces are some of the common errors Beyer Air Conditioning & Heating professionals help clients rectify. So, how do you know your furnace is too big or small? Here are the telltale signs.
It Runs Continuously
Does your furnace constantly run, yet it fails to keep your house at optimal temperature? It means the unit is too small.
Turns On and Off Too Often
A unit that restarts frequently is probably too big for your house. It quickly turns off soon as it heats indoor air to the desired level. This also causes the system to age prematurely.
You have Scheduled More Than Two Repairs in a Year
Generally, homeowners should call HVAC pros for routine maintenance at least twice a year. If your furnace has been repaired more than two times, wrong sizing might be the culprit.
Call Top-rated Installers to Install Correctly Sized Furnaces
At Beyer Air Conditioning & Heating, we help clients curb unnecessary heating and cooling expenses by ensuring they have suitable systems in place. We are a family-owned HVAC company serving residential and commercial households in San Antonio, Bulverde, New Braunfels, Helotes, Boerne, Schertz, Alamo Heights, and nearby places. Our NATE-certified technicians are honest, respectful, and highly skilled. We run a BBB-accredited business so that you can trust our HVAC practices and customer service.
An inoperable furnace does more harm than good, threatening your home’s comfort. Luckily, our team is on duty 24/7 to handle all emergency calls. Our service has no surprise costs and what we quote is exactly what you pay. We will do everything possible to fix your furnaces, ducts, VRF systems, heaters, and AC units. We won’t leave your premises until you are 100% satisfied.