Is My Furnace Energy Efficient?
In this post, we explore what makes for an energy-efficient furnace, how you can tell if your gas furnace is excessively guzzling energy, what you can do in your home to facilitate greater efficiency, and more.
What Factors Determine an Energy-Efficient Furnace?
Right now, energy costs and energy efficiency are top of mind. Homeowners want to know what they can do to reduce the costs of heating their homes.
Conventional gas furnaces are prone to loss of efficiency over time. The older they get, the more energy they require to produce the same heat output.
The primary determinant of conventional gas furnace efficiency is its maintenance history. Gas furnaces that are maintained at regular intervals are less likely to create problems that result in reduced efficiency.
The condition of the air filter can also have a significant impact on your furnace’s efficiency. A dirty filter blocks airflow into the unit, forcing the system as a whole to work harder. Fortunately, a clogged filter is easy to replace during your annual scheduled maintenance.
Thermostat settings can also affect energy costs. Thermostat calls are signals that the temperature regulation unit sends to the furnace. The lower you set it, the fewer signals it will send, and the less energy you will consume. However, thermostats by themselves cannot directly improve efficiency.
Insulation can also impact energy bills. Not only is it critical for quiet operation, but it also helps to contain the heat generated by the furnace. Quality insulation is important to keep warm air inside and cold air outside the house. Have you ever felt a cold draft or cool air sinking through your walls from the outside. You may have poor installation in your home. If you invest now in an installation inspection and a specialist upgrades your installation, you will save money in the long run.
Lastly, you’ll want to check for air leaks. Cool air entering the system not only affects indoor air quality but also increases your energy bills. Again, maintenance services can check for leaks and systematically seal them.
How do you Check your Furnace’s Annual Fuel Utilization Efficiency?
In general, there are two ways to determine the energy efficiency of your furnace. The first is simply to look at the AFUE (Annual Fuel Utilization Efficiency) rating on the unit. Usually, you can find this in the user manual. The AFUE tells you how much of the fuel source that goes into the boiler gets turned into usable heating.
High-efficiency furnaces tend to have AFUE ratings of 90 percent or more. This means these high-efficiency furnaces produce heat at a higher rate given a supply of fuel. They turn 100 units of natural gas into 90 or more BTUs (British Thermal Units), on average, over the course of a year. The US Department of Energy only gives Energy Star labels to furnaces in this category.
Most furnaces have an AFUE of around 85 percent in the US. Regulations introduced in 2015 state that efficiency cannot fall below 81 percent.
The other way to check the energy efficiency of your furnace is to monitor your spending over time. Even an efficient model can eventually start consuming more natural gas, putting up your costs. Check how much you’re spending this year compared to last year to see if there is a noticeable difference. If you are not sure whether heating efficiency is declining, contact a furnace repair technician.
What Can be Done to Make Your Furnace More Efficient?
There are many ways to make your air conditioning and heating system more efficient. Here’s what to do:
- Clean the air filter: The furnace filter on your unit prevents hair and other debris from entering sensitive internal areas. However, a clogged filter limits the amount of air that can get into the system, making it less efficient over time. The solution is simple: replace the air filter every year and check it monthly to make sure that it’s free from debris. Doing this will ensure that outdoor air headed into your furnace filter does so more efficiently.
- Clean the vents: On a similar theme, you’ll also want to tour all your home’s vents and check they are free from obstacles and obstructions. Clean them thoroughly at least once per year as they have a habit of attracting lint and other debris.
- Tune-up: Even efficient furnaces require a tune-up from time to time. These check the blower motor, standing pilot light, limit switch, and other components of the system.
- Clean out the furnace: You can also clean out the furnace by removing the access panel. Before you do so, make sure to switch off the pilot light and electricity supply. Failing to do so could be a fire hazard.
Is Furnace Maintenance Necessary?
Many people get their air conditioner serviced every year, but is it worth doing the same for a furnace?
Most furnace manufacturers recommend that people get annual maintenance by a certified technician. In fact, they assume regular inspections when designing units. Just like cars, servicing a furnace blower motor allows it to last longer.
Moreover, some vendors may insist on annual checkups to avoid voiding the warranty, but this is rare. Most will still provide cover on furnaces up to around ten years old. After that, you should replace it.
What is a Furnace Tune-Up?
There is no industry standard for a furnace tune-up, but it usually includes the following:
- Checking filters and making sure they are not clogged and damaged
- Checking the wiring for corrosion and damage, and replacing it where necessary
- Performing an amp-draw test to see whether it matches the manufacturer’s specifications (deviations may indicate an issue with the internal circuitry)
- Testing that faulty electrics trip the circuit breaker
- Ensuring that the drainage system is free from blockages and leaks, including testing the internal hoses
- Cleaning the condensate drain
- Inspecting burners to ensure proper hot surface ignition
- Ensuring that electronic ignition works correctly in applicable units
- Inspecting the heat exchanger for corrosion or rust
- Checking air intake louvers for blockage
- Inspecting the variable-speed blower motor
- Checking that the furnace blower door forms a tight seal with the furnace
- Checking the gas line and gas burners
- Make sure that the exhaust gasses correspond to the unit’s specifications
- Checking that there is no system leakage and that the gas valve is operating correctly
While furnaces don’t have the same number of moving parts as motor vehicles, they still operate under tight tolerances. There are multiple points of failure.
Can Homeowners Perform Their Own Gas Furnace Maintenance?
Homeowners should not attempt to maintain furnaces themselves. Doing so could be hazardous. Furnaces rely on natural gas, a highly flammable and toxic substance if breathed in. Heating systems also operate under exceptionally high pressure. Failure to manage this professionally could lead to serious injury.
Certified furnace inspectors save time and money while also keeping you safe. Their expertise in heating equipment allows them to perform all of the tasks mentioned in the list above, and more, as they see fit. If you have an HVAC, they can also work on your cooling system at the same time.
Are Heat Pumps More Efficient than Gas and Oil Furnaces?
Heat pumps are a part of central heating and cooling systems that use outside air to warm the home in the winter and cool it in the summer. It is a type of heat exchanger that changes its operation, depending on the season.
Many people opt for a heat pump because they believe that it is more efficient than a regular furnace. Amazingly, heat pumps can transfer around 300 percent more energy than they consume, compared to the top gas furnaces which are only 95 percent efficient, because they draw heat from the environment. However, the degree of efficiency depends on the climate.
How Can You Make Your Home More Energy Efficient?
Solely relying on sealed combustion in your furnace to make your home more energy efficient is only one part of the story. If you really want to get the most out of your furnace, you need to look beyond higher efficiency models to what you can actually do in your home to reduce the electricity required for heating.
Lower your thermostat
Ask yourself whether you really need to set the thermostat at a constant 75 degrees F throughout the winter, or if you could manage with 68 degrees F and wear a wooly jumper instead — the EPA’s recommendation. The less you work the heating element, the less power you will draw.
Seal your windows to prevent heated air from escaping
You can also get more out of your heating equipment by sealing all your windows. Preventing heated air from escaping is easy: just apply a layer of sealing caulk around your windows and any cracks in your drywall. Also, look for gaps around your air conditioning unit’s ducts as they interface with your walls.
Add insulation to your attic
Surprising as it may sound, adding insulation to your attic will make both your air conditioning and gas furnace work better. The more you can prevent heat transfer — either in or out of your home — the lower your bills.
Buy an Energy Star furnace with an efficient heat exchanger
Not all heating systems are created equal: some sip on natural gas frugally, while others devour it. If you’re in the market for a gas furnace, check the EPA rating on the unit. Make sure that you avoid paying for more heating energy than absolutely necessary.
Check your limit switch
The limit switch is a component of a forced-air furnace responsible for switching off the blower motor once you reach the desired level of heat. Check that this is working in your furnace to make sure that it is heating your home optimally.
How long will a furnace remain efficient?
High-efficiency furnaces tend to be more expensive than regular furnaces, but they also maintain their efficiency for longer.
Generally, furnaces last between fifteen and twenty years if you take good care of them. Being diligent with annual maintenance may even allow you to extend their lives further.
Unfortunately, most furnaces lose efficiency as they age, including high-efficiency varieties. Generally speaking, furnaces lose around 20 to 40 percent of their heating efficiency after many years of use. This occurs for multiple reasons, including dust buildup, vibrations, and damage to the heating element. In some cases, a house’s electrical system may interfere with the furnace, eventually causing heat loss.
Does Furnace Size Affect Efficiency?
The size of your furnace determines how efficiently it will deliver heat to your home. Generally speaking, you’ll want to choose an optimally-sized furnace for your accommodation. Choosing a furnace that’s too small will result in less heating output than you need, while one that is too big will result in too much heat.
Small furnaces have less heat output, so they will have to work overtime, even if they are high-efficiency. One that is too large may wind up heating the home too efficiently, leading to overshoot.
What Signs are there that Your Furnace is Not Operating Efficiently?
There are many signs on both gas and oil furnaces that they are not working at high efficiency. These include:
- Repeatedly cycling the power switch between on and off, or displaying a flashing light. Usually, this indicates that the motor is dying
- A yellow pilot light, indicating a dirty burner flame
- A rusted flue
- Moisture buildup in your home — a sign that your heating system isn’t properly venting
- Higher utility bills — often a consequence of a blocked filter and overactive motor
- Difficult producing heat
- Water leaks — usually an indication of a clogged condensate line
- The need to tweak your thermostat constantly
- Repeated service callouts
- Cold spots in your home
- An eerie silence from your furnace, even when switched on
- A smell of natural gas