To find out your furnace's efficiency, first check the vents. If your furnace vents out of a metal pipe and/or chimney flue, it's a low-efficiency or “standard” furnace. If it vents out of a plastic PVC pipe, it's high-efficiency.
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.
How to find your furnace's energy efficiency rating. Locate the AFUE on the bright yellow label located on the outside of the furnace. This label will also tell you if the furnace is high efficiency. An AFUE of 90% or above is considered high-efficiency and the minimum standard for a new furnace is 78%.
A high efficiency gas furnace has AFUE ratings of 90% or higher, up to a maximum of 98.5% AFUE. AFUE stands for Annual Fuel Utilization Efficiency, and is a measure of how much heat the furnace can pull from the fuel it consumes, ultimately determining how energy efficient a heating and cooling system is.
Lennox has the highest possible AFUE rating on this list. Its Dave Lennox Signature Collection, particularly the SLP99V model, achieves an outstanding 99% AFUE rating, currently the highest efficiency rating available in residential furnaces.
Then, sometime in the early 1980s Lennox came up with its high-efficiency “Pulse” furnace, which was probably one of the best-publicized new products in our industry since I can't remember when.
Well, it turns out that both standard, 80% efficiency units and high-efficiency 95% systems are available as single-stage or two-stage units. An 80% efficiency, two-stage furnace will often beat the energy savings of a 95% single stage furnace.
You can find your system's AFUE rating displayed on the Energy Guide sticker on your unit.
Standard Efficiency : The most basic furnace being manufactured today, a standard or mid-efficiency furnace has an AFUE rating of around 80%. High Efficiency : If a furnace is considered a 'high-efficiency furnace,' it is rated as 90% AFUE or more.
You can find the model and serial numbers (M/N and S/N) for your furnace by removing the top-front service panel and looking to the left side of the interior cabinet or the top of the blower deck, depending on whether your system is an 80% or 90% AFUE unit.
Look at the outdoor unit. It should have a label identifying it as an air conditioner or heat pump. No label? Search the brand and model online.
In case of combustion type furnace, depending upon the kind of combustion, it can be broadly classified as oil fired, coal fired or gas fired.
The most straightforward way to tell if your furnace is gas or electric is to check its fuel source. A gas furnace connects to a gas supply line. You can usually find a gas meter or gas pipes near it. On the other hand, electric furnaces don't require a gas supply and connect to your home's electrical system.
Known as the Energy Efficient Home Improvement Tax Credit, this program allows you to earn a tax credit of up to $3,200 a year. The program started on January 1, 2023, and will run until December 31, 2032, which means you may be eligible if you upgrade or replace any HVAC unit within the next decade.
Non-Condensing Furnace: A mid-efficiency furnace (80% and 90% AFUE) vents exhaust gases out of the home, typically through the roof. Condensing Furnace:A high-efficiency furnace (90% AFUE or higher) utilizes a second heat exchanger to heat the air from condensed exhaust gases in order to reach higher efficiencies.
Check Your Heating Equipment's AFUE Rating
AFUE, or Annual Fuel Utilization Efficiency, determines what percentage of fuel your equipment can turn into heat. For example, an AFUE of 75% means that ¾ of your heating oil will be transformed into heat, while ¼ is the by-product.
How You Can Tell if it's a High-Efficiency Furnace? A high-efficiency furnace is specifically a furnace that has an annual fuel utilization efficiency (AFUE) rating of 80% or more. The best has 97% or higher AFUEs. That's very helpful if you're looking at a furnace available for sale, where metrics are easy to find.
In other words, AFUE represents the amount of fuel that is used to create heat. The AFUE percentage is calculated by dividing the amount of fuel supplied to the heater by the amount of heat produced by the unit (usually in Btu).
What is the difference between high efficiency and standard efficiency furnaces? Standard-efficiency furnaces convert roughly 80% of the energy from gas into heat. High-efficiency furnaces convert 90-97% (depending on the model) of the energy from gas into heat. So basically: high-efficiency furnaces use less fuel.
There's a simple way to find out the energy efficiency of your home's furnace: Look at its AFUE rating. This number, found on the cabinet or in the user manual, is the Annual Fuel Utilization Efficiency measurement.
An 18 to 20-year-old furnace will measure more than 20% inefficiency, meaning 80% of the power (gas or electricity) goes to heating your home, while 20% is wasted. A new high-efficiency furnace will read between 90-95 AFUE, meaning 90-95% of the power used goes to heating your home, and only 5 – 10% is wasted.
A well-maintained, high-efficiency furnace, on the other hand, is usually able to last 20 to 30 years. As a result, scheduling an annual maintenance appointment with an experienced HVAC company in your area is one of the most effective ways to ensure your home's furnace stays efficient for as long as possible.
Without cold air returns, your system would struggle to pull in the air it needs. This could lead to inefficiencies, higher energy costs and potentially uneven temperatures throughout your home.
Without proper drainage, that condensation from your furnace would accumulate in the heat exchanger and in the vent, making it difficult to heat the air properly. In fact, many high-efficiency furnaces have two drains: one in the secondary heat exchanger and one in the vent.