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Residential Heating and Air Conditioning Blog

Should I Buy 80 or 95 Efficiency Furnace?

Winter is here, the holiday season is almost over, and you’re putting your heater to good use. If you’ve started to realize that your heater isn’t performing the way you want it to anymore, then it’s time to schedule an appointment for a potential furnace replacement in Minnetonka, MN. Replacement is a job that we can perform for you. 

Replacement and installation services are two of the important jobs you can have done for your heater. If you’re looking for a team that will make sure that your furnace gets the service it deserves, then it’s time to get in touch with us. We have a full team of technicians who have the experience they can put to use for you. Today, we’re going to start from the bottom up–we want to give you the necessary information to get a high-quality furnace.

What’s the Difference Between an 80% and 95% Furnace?

Let’s start off by defining the difference between an 80% efficiency furnace and a 95% efficiency furnace. 

We want to start things off by mentioning the AFUE rating. The AFUE (or Annual Fuel Utilization Efficiency) rating is a tool used to measure a furnace’s efficiency. If you have an 80% AFUE-rated furnace, it means 20% of the energy produced by natural gas is expelled as exhaust. While 80% AFUE-rated systems were more common in the past, there are systems with up to 95% AFUE ratings available today.

This might be obvious, but a 95% AFUE-rated furnace is more efficient than an 80% system. For some people, it may initially seem that the choice between the two is obvious. You want a system that’s more efficient, right? 

The answer is actually: not always. The efficiency isn’t the only thing that’s different between these two systems. The way these two systems work is also vastly different. An 80% furnace vacuums in the air from the surrounding area to produce warmth. This is also known as open combustion. A 95% furnace sucks air in from the outdoors in a sealed combustion system. In certain circumstances, an 80% AFUE rated system might suit a home’s needs better than a 95% AFUE rated system can. 

Other Important Factors That Impact Furnace Efficiency

Your furnace’s AFUE rating isn’t the only thing that’s going to factor into your furnace’s efficiency. If efficiency is high on the list of things you want from your heater, then you should also consider the type of heater you’re choosing regarding stages and speeds.

For example, lots of homeowners choose single-stage furnaces. These systems only have one setting and that’s on or off. When your heater is on, it runs on full blast. A two-stage furnace can offer you another stage. It’s has on (100% capacity), a slow speed (65%), and off. 

Now let’s discuss modulation. A furnace with a modulated gas valve is similar to a two-stage furnace. It operates at a variety of capacities to match your fluctuating heating needs. 

We say all this to say that there are no absolutes in furnace efficiency. A variable speed 80% AFUE rated furnace is likely to be more efficient than a single stage 95% AFUE rated furnace. This is why you should discuss your options with us. 

Contact Residential Heating and Air Conditioning to schedule an appointment with our professionals. 

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