Efficiency ratings on Furnaces and Air Conditioners

What do the numbers mean?

It’s time to buy a new furnace, or you’re tired of hot sticky nights and are looking to purchase an air conditioner. But how do you make a decision? What do all of those energy efficiency ratings tell you?

With natural gas prices more than tripling in the past ten years, it’s an important consideration to look at the numbers. Efficiency ratings of new furnaces have been increasing as well, however. Fifteen years ago, most heating systems installed at the time were only 60-80% efficient and very old units less than 50%. New furnaces are 90-98% efficient and can reduce your heating costs by up to 40%.

The Annual Fuel Utilization Efficiency (AFUE) is the percentage you see on the specs for a furnace. AFUE measures a gas furnace’s efficiency in converting fuel to energy. The higher the rating means the more significant the energy efficiency or heating performance.

Keep in mind that AFUE is only the efficiency of that furnace to convert fuel into heat. The higher the number, the better it is at that conversion. So, yes, that will save in energy costs. But the higher-efficiency furnaces also cost more than their lower-efficiency models. That’s something to consider when new-furnace shopping. You need to weigh these factors against one another, as well as the cost of your type of furnace fuel when looking to make that decision.

When it comes to furnaces, FortisBC currently has great rebates that can help, and the rebate is more for a higher efficiency furnace — another factor to build into your decision-making process.

As well, if you have some long term goals for living in your home, a higher AFUE will be the way to go. It will cost less in the long run (particularly with continually rising energy costs) and could be a decisive factor when you do decide to sell in the future. Many savvy home buyers will consider that.
There’s a whole different set of numbers when it comes to air conditioning. An air conditioner’s efficiency is measured by its SEER (Seasonal Energy Efficiency Ratio) rating.

Many people suggest that you consider a SEER rating is being like the miles-to-the-gallon ratio that cars have, except in this case, it’s the amount of cool//warm air to unit of energy that is used. The higher the SEER rating is, the more efficient the heating or cooling unit is.

To ensure you’re purchasing an HVAC unit with a high SEER rating, look at units that are approved by Energy Star, as those units must have a SEER rating of at least 14.5 to meet the standards. Gandy Installations can offer up to 26 SEER units!

The higher the SEER rating, the more money you will save over the long term, but there’s more than just numbers here. A higher SEER usually has two-stage technology that means your air conditioner doesn’t have to run at 100% in every circumstance but can adjust to load requirements. A low-stage demand from the thermostat can result in up to 35% speed reductions at both the compressor and indoor unit circulating fan. Two-stage cooling generally occurs in extended operation at a low speed, providing improved indoor comfort, and using less electricity than single-stage systems and less wear and tear on the unit. And when you look at it, improved indoor comfort is why you’re considering an air conditioner in the first place. There are also fully modulating furnaces and air conditioners that adjust their input in 1% increments allowing for 65 stages of heating/cooling when paired with the appropriate thermostat.

Numbers are important in making your final decision, but there are additional factors that can influence cooling and heating and home comfort.
The friendly folks at Gandy can help. They can educate you on all the different types of systems and help you choose the one that is best for you and your budget, and will then provide you with upfront pricing so that you know the exact cost of the work before they begin.