Tuckers Air Conditioning, Heating & Plumbing Blog

The Two Heating Ratings You Should Know About

If you’re currently looking for a new heating system, you might be more than a little overwhelmed by the choices you have available. Amid the sea of different models, fuel types, and other configurations, it can be all too easy to gloss over things that should really not be ignored. One of those things is efficiency ratings. Before you settle on a new heating system, whether it’s a furnace or a heat pump, you need to know the efficiency ratings and what they mean. Otherwise, you may find yourself with a system that doesn’t meet your heating needs properly.


If you’re installing a combustion based system, like a furnace, you’re going to need to know about AFUE. AFUE stands for Annual Fuel Utilization Efficiency, and is the primary measurement of how cost-effective the furnace is going to be during operation. The rating is determined by the ratio of BTU’s (British Thermal Units) of fuel put into the system vs the amount of BTU’s that come out of it. So, if you put 100 BTU’s of fuel into a furnace, and you get 90 BTU’s of heat out of it, the furnace has an AFUE rating of 90%.

Generally, you’re going to want to find a heating system with an AFUE of higher than 80. Less than that, and a lot of the time the fuel waste simply isn’t worth it. If you’re not sure about how to determine the best AFUE rating for your needs, consult with a professional. Better to be cautious now, than regret your choice later.


AFUE isn’t the only rating used for heating systems. If you’re looking for a heat pump system, you’ll be going by HSPF. HSPF stands for Heating Seasonal Performance Factor, and measures the efficiency of electrical systems. This rating system actually applies to air conditioners, as well as heaters, since it measures the amount of BTU output over the heating season to watt-hours of electricity used. Basically, the ratio measures how much heat the system is capable of moving for every hour of electricity it’s provided. The formula can get rather complicated from there. Again, though, what matters is that you find a system with an HSPF that matches your needs. HSPF is not presented as a numeral from 1-100, as AFUE is. Instead, it’s a scale from 1-10, with 10 being the highest. An HSPF of 8 or greater is typically considered “high efficiency.”

As with AFUE, you should make absolutely sure that the HSPF is satisfactory before you install a heat pump system in your home. If you aren’t sure exactly about the rating system, have a professional go over it with you. It’s far better to make sure that you’re making the right choice now, then to install the wrong system and have to replace it later on.

Tuckers Air Conditioning, Heating & Plumbing provides a full range of heating installation services in Gaithersburg, MD. If you need help finding a new heating system, contact us today and we’ll walk through the process with you.