By: Brian Schutt
As we discussed with Pete the Planner this morning on WIBC, heating and cooling energy efficiency can be a confusing thing for homeowners. Not only does no universal definition exist, but it’s also a moving target depending on what appliance you’re shopping for, and as government standards change that definition does as well.
If you’re looking at buying a new gas furnace, there are two areas of gaining efficiency: fuel utilization and moving the air. Currently, the government’s definition of high efficiency starts at 95% AFUE (annual fuel utilization efficiency). That essentially means that 95% of the heat produced by the furnace is coming out of the vents. With the base level of efficiency at 80%, this move would garner you a 15% improvement in fuel utilization. The net of that should mean that over a year you’ll use less gas to have the same amount of comfort.
The second area of efficiency for your gas furnace is moving the air. The base-level systems will have a single-speed blower, so the system is either on or off. The loss of efficiency comes from the fact that sometimes to be most comfortable, the airflow needs to be at half speed or 2/3 speed. That’s where a variable speed blower motor yields an increased inefficiency. By only using half-speed we’ll pull less electricity, therefore gain efficiency in our operation.
We always recommend homeowners ask their heating and cooling firm about an operating cost calculator to compare the different options available when purchasing a new system. That should assist you in determining how long the increase in price for high efficiency will take you to pay back. That’s why a big factor in selecting a new furnace should be the length of time you will be in the home. A high-efficiency furnace payback can take 3-5 years. Whereas an air conditioner can take a few years longer.
Have questions about heating and cooling energy efficiency or need work on your HVAC system? Tweet us @TrustHomesense or call us at (317) 203-8149.