What is an A.F.U.E. (Annual Fuel Utilization Efficiency) rating and what do they mean to you?
The efficiency of a furnace is measured in a rating known as A.F.U.E. (Annual Fuel Utilization Efficiency). A lot like your car’s miles per gallon rating, A.F.U.E. tells you how efficiently the furnace converts fuel (gas, oil or propane) into heat. An A.F.U.E. of 80% means that 80% of the fuel is used to heat your home, while the other 20% basically goes up the chimney.
In 1992, the government mandated a minimum A.F.U.E. rating of 78% for furnaces installed in new homes. (In contrast, many furnaces manufactured before 1992 had A.F.U.E. ratings as low as 60% – so nearly half the fuel was being wasted.) Furnaces with A.F.U.E. ratings of 78% to 80% are considered “mid-efficiency”, while those with ratings of 90% or higher are termed “high efficiency”.
In general, a higher efficiency furnace usually means two things.
* lower monthly operating costs
* higher comfort levels
If you have an older furnace (10 – 15 years old with an estimated A.F.U.E. of around 60%), you could save up to 40% on your heating bills by replacing it with a new high-efficiency furnace. So the cost to replace your older, inefficient furnace is paid back through lower utility bills.
What is a Modulating or Two-stage furnace?
Modulating Furnace: Most furnaces are either “off”, providing no heat, or “on” at full capacity, with the burner and blower operating at 100%. This causes the temperature in your house to go up and down by several degrees – affecting both your comfort and your energy bills. Furnaces are designed to keep your home warm on the coldest of days. But in most cases, those days account for only 2-1/2 percent of the heating season. The rest of the time, you furnace is providing more heat than is needed to satisfy your comfort requirements. Modulating furnaces solve this problem by “modulating” between different capacities (40-100%), depending upon the comfort requirements of the homeowner and the temperature outside. This results in lower operating costs, quieter operation and much more even temperatures throughout the home. It’s like having a separate furnace to handle the unique heating requirements of each day – all in one unit! Check out the Rheem Modulating Furnace with Contour Comfort Control – the only truly modulating gas furnace in the world!
Two Stage Furnace: A two-stage furnace has the same concept in mind as a modulating furnace. The difference lies in the fact that while a modulating furnace can operate at any capacity between 40% and 100%, a two-stage furnace operates on a low-stage and a high-stage. The low and high stages have preset BTU outputs. On most days, the furnace will operate at its first stage to only provide the heat you need to stay comfortable. On those very coldest days of the year, this furnace will ramp up to its second stage and give the full BTU output of the furnace to keep satisfying the heating requirements of the home. It’s basically like having two furnaces in one – one for warmer days and one for the very coldest.
Do I need to get my furnace cleaned every year?
Naturally, you would expect a heating contractor to recommend an annual furnace cleaning as we do. But we do so for a number of reasons. A cleaning means that your furnace will operate more efficiently, getting more heat for your fuel dollar. More importantly, however, the cleaning also includes a thorough safety check of the entire unit for cracked or defective/damaged parts. This annual maintenance check will assure you a carbon monoxide free winter. An annual cleaning is also recommended by all manufacturers as well as utilities.
How often should I change the standard throw-away 1 filter on my furnace?
You should change your standard 1″ filter every 6-8 weeks. Believe it or not, a filter actually becomes more efficient as it gets dirtier – up to a point. After peak efficiency is reached, the efficiency drops again. Make sure to inspect the filter and use your own judgment. Don’t let the filter get “clogged” as this can cut down on the efficiency and/or cause damage to the unit.
How can I make sure that my HVAC system is safe for operation?
Always have your system checked annually to make sure that the unit is safe. In many cases, tiny cracks or perforations in the heat exchanger occur. If you furnace is burning inefficiently or incompletely, carbon monoxide can escape and fill the house causing serious health problems and/or death to those inside.
If I go away for a few days or even longer during the winter, at what temperature should I set my thermostat?
We recommend 55 degrees. It’s low enough to save you energy and money but warm enough to protect your pipes and other vital parts of your structure. Also, it’s a good idea to turn your main water supply off even if you’re only going to be gone for a day. A water leak could cause serious and very costly damage to your home.
My thermostat is equipped with two position settings for the fan, 'automatic' and 'on'. Where should I set it?
The two positions are usually used in conjunction with a central air cleaning system. The normal setting is on “automatic” and the fan’s cycle will be controlled by the temperature in the room. However, if your home is equipped with an air cleaner (media or electronic) or you wish to keep a continuous flow of air, switch the setting to “on”. Remember, central air cleaning devices only work when the furnace is circulating air. If you wish to get the most from your air cleaner, you should keep the setting to “on”.
I have trouble getting even amounts of heat/cooling to certain parts of my house. How can I get more heat/cooling to the upstairs/downstairs of my home?
Adjust the louvers inside the registers on the wall or floor in the room where too much heat/cooling is present so that the registers are partially closed. For example, to get more cooling upstairs during hot summer months, partially or fully close the registers downstairs to force more airflow to the upstairs registers.
Another possible solution is a furnace equipped with a variable speed blower motor. These furnaces are designed to overcome airflow problems in a home and will keep the airflow steady all over the home. These types of furnaces also use about 1/3 the electricity of a standard furnace and can save considerable amounts of money in operating costs.
A zoning system is also a possible solution to this problem. Zoning is the controlled delivery of heated or cooled air to a particular area of the home, without heating and cooling the entire home. Temperatures can be set and maintained independently throughout the home through the use of multiple thermostats.
Does it pay to turn down the thermostat at night or when you leave your home for any length of time during the day?
Yes, there would be some fuel savings but we do not recommend lowering your thermostat by more than 5-7 degrees. You might think about the purchase of a programmable thermostat. It would do the job for you automatically.