Energy efficiency and your HVAC system: a primer
HVAC energy efficiency is an important topic to understand as you make decisions regarding your home’s heating and cooling system. There are a multitude of factors and ratings that go into determining and describing energy efficiency. As always, our goal is to help reduce confusion so that you, the customer, have the knowledge necessary to make important decisions. First we’ll focus on describing the various energy efficiency ratings. Then we’ll dive into the parts of your system that most affect efficiency. Finally, we’ll reference our main units and how they rate within energy efficiency.
Energy Efficiency Ratings
When considering a new system, you want to look at its energy ratings. The higher the rating with each of these, the better the system will run. In other words, a higher number means a system will use less energy to heat and cool your home.
SEER– this stands for Seasonal Energy Efficiency Ratio and is for air conditioners. Again, the higher the SEER number, the more efficient the unit. The current highest SEER in the Daikin line is 23, with other units coming in at 12 or above.
AFUE– this stands for Annual Fuel Utilization Efficiency and is relevant to gas furnaces. AFUE is a percentage that shows how much the furnace’s energy source is converted to heating, with the rest being lost to exhaust. So then, a higher percentage means less energy lost. Side note: an electric furnace technically has an AFUE rating of 100%, but that’s because it can’t lose any of its energy to exhaust. So while an electric furnace may have a 100% AFUE rating, that doesn’t technically mean its more efficient/will cost less. Energy efficient units will have AFUE in the 90s, while standard units will be in the 80s.
HSPF– this stands for Heating Seasonal Performance Factor and is used with heat pumps. This is, in essence, the SEER rating for a heat pumps heating mode. Most heat pumps will come with both a SEER (cooling) and HSPF (heating) rating. You should be looking for an HSPF between at least 8-10, though some can reach above 12.
Factors that affect efficiency
You’ll see some of the terms below mentioned when as you read more about HVAC energy efficiency. Here’s what they mean and how they affect the unit:
Multi-stage vs. Single-stage– “stage” is a reference to the level of power that is used to heat or cool your home. A single-stage unit only has one setting. It uses full power all the time, no matter the temperature, to regulate your home. Sometimes this is the right amount of power needed, but many times it is an unnecessary amount. Conversely, a multi-stage unit can alternate its level of power to the necessary amount in the moment. This reduces unnecessary energy use in less extreme temperature conditions. For this reason, multi-stage units are more energy efficient.
Variable Speed vs. Single Speed- this refers to the way the blower motor within the unit works. Like the stages above, a single speed motor always blows air at the same setting. Variable speed motors are able to switch their power setting to save energy when it’s not needed. As you can imagine, variable speed units are more efficient.
Unit size- It’s important to ensure that you install the correct sized unit for your home. If your unit is too small for your home, as we outline here, it will struggle to keep up with the demand. This will put an unnecessary amount of strain on the unit. On the other hand, having a unit too big for your home will cause it to turn on and off consistently, also wasting energy.
How efficiency affects you
According to Energy.gov, your heating and air conditioning system costs more than any other system in your home. On average it makes up about 48% of your utility bill. By understanding your options as they relate to HVAC energy efficiency, you can help determine how much you’ll spend on your utility bill. While high efficiency units do cost more up front, they are able to make up their cost within a handful of years in many cases through lower utility bills. You can check out this list of our main air conditioner product line to see what might be best for you.
In the end, there’s not a one-size-fits-all approach to determining the right units for your system. Taking the above factors and ratings into account, as well as the size of your home and budget, will help you find the right fit. To learn more about all things AC related, including more information on efficiency, see our AC Repair and Replacement Guide.
For any additional questions or help finding the right unit for you, give us a call at 317-203-8149 or set up an appointment online.