Furnaces, Boilers, and Heat Efficiency: A Guide to AFUE Ratings

energy guideThe measure of a boiler or central furnace’s efficiency is determined by what’s known as “Annual Fuel Utilization Efficiency”, or an AFUE for short. An AFUE, as the name implies, looks at how well boilers and furnace models use fuel to heat a home on a yearly basis.

Currently, manufacturers of either boilers or furnaces are required by the Federal Trade Commission to display their AFUE. This move towards transparency allows prospective buyers to know what they can expect in terms of heating efficiency as they seek to make informed purchasing decisions.

A Little More About AFUE Ratings

AFUE is a ratio that’s determined by weighing the total heat produced by the appliance against the total amount of fossil fuel energy it consumes each year. An AFUE rating of 90% tells an individual that approximately 90% of the fossil fuel energy used will be converted into heat for home while the remaining 10% is displaced or sent elsewhere.

Despite the convenience of efficiency being condensed into a single number, it’s worth noting that AFUE isn’t a percentage that factors in losses associated with pipes or the duct system, although these can account for up to 35% of the energy. This is especially true when ducts are situated in unconditioned areas such as garages and attics.

What About Electric Furnaces and Boilers?

A major strength associated with boilers or furnaces that run purely on electricity is that there are no heat losses via chimneys and the like. Typically, with all-electric appliances of this nature, the AFUE rating is in the range of 95% to 100%. At the lower end of this range are outdoor units which are associated with larger amounts of heat loss. Another concern is the expense of electricity in certain cities, which in turn makes all-electric boilers and furnaces impractical. Those who are intrigued by electric heating may be better-served with heat pump technology, or the new tankless hot water on demand systems.

What’s the Minimum AFUE Rating?

The lowest allowable AFUE rating allowed for a home furnace is 78% unless the purchase is for a mobile home in which case the threshold is 75%. It’s expected that in the future AFUE minimums for furnaces will be decided on the basis of a number of factors such as indoor or outdoor installation, fuel usage, and whether the furnace is designed for use in a mobile home.

In the case of a boiler, AFUE minimums depend on both the means of heating and the fuel used. For example, a gas-based water boiler the AFUE minimum is 82% while a water boiler that’s oil-fired has a number of 84%. Meanwhile, an oil-based steam boiler has a minimum AFUE rating of 82%. Further conditions include hot water boilers needing the ability to automatically adjust the water temperature while a gas-fired boiler isn’t allowed to burn constantly.

Condensing v Non-Condensing

The difference a condensing boiler or furnace makes is in the way that it takes water vapor and uses it to provide heat. AFUE ratings for this type of appliance are often significantly higher than other types. These furnaces and boilers are often more costly than their non-condensing counterparts, but they pay-off over time and are often more economical in places with harsh winters.

The efficiency of a system can also be discovered by examining a unit’s equipment features.

Older and less efficient:

  • Constant-burning pilot
  • AFUE of 56%-70%
  • Use of a natural draft with combustion gasses
  • Heat exchange

Mid-Efficiency Heating:

  • Ignition uses electricity
  • Flue pipes in smaller size
  • AFUE ratings of 80%-83%
  • A more precise exhaust fan has a greater degree of control over the combustion process
  • Smaller unit size and reduced weight leading to more efficient cycles

Higher-Efficiency Heating:

  • Combustion is a sealed process
  • AFUE ratings in the range of 90%-98.5%
  • A second heat exchanger allows the system to further condense flue gasses

For more information on this subject visit the appropriate government page on heat and energy for furnaces and boilers.

Helpful Tips for Maintaining The Furnace

Maintaining a furnace is a do-it-yourself task that does not require technical expertise. Its effectiveness and efficiency can only be determined by the level of care offered. When maintaining a high functional burner, it is important to subject it to regular cleaning and maintenance. This can only be ensured by knowing each component and how it should be handled during cleaning. Therefore, it is important to familiarize yourself with all its components and the right measurements you should have for your burner. The main components in a cleaner are discussed below, as well as, how they should be maintained.

Oil and Gas Burners

Using gas or oil in burners depends on the type of furnace you are cleaning. Normally, oil burners are known to involve less complicated technology and tools in comparison to oil burners. Gas burners require more maintenance owing to the high level of technology and equipment associated. Therefore a professional technician should do such maintenance techniques as inspecting flames and pilot mechanism. However, simple practices like cleaning the burners can be done at home yourself to maintain a longer span of the cleaner. Before checking it is imperative to turn off the burners, gas supply line and the pilot light.

Brushes for Cleaning

Not all brushes are suitable for cleaning soot, especially for oil. In order to figure out which brush to use, you should first know which model is you are using. By using the recommended brush, cleanliness is maintained, and this increases its efficiency and span. Grainger illustrates different brushes suitable for different furnaces. For instance, a pin boiler requires a wire bristle brush with a diameter of 1/2″. Safety gear as goggles are indispensable in this case, and then you can slowly brush it diagonally until all the soot is removed.

Combustion Compartment

This is the most essential part you should consider cleaning. The compartment is subject to getting dust, cobwebs, and rust. These contaminants are dangerous for the functioning of the compartment, and should be eliminated as soon as possible. It is recommended to use a long nozzle that can penetrate the long wires and cabinets. By using the nozzle, one will be able to trap cobwebs, rust and even dust. Always make sure that there is adequate supply of oxygen around the combustion compartment to avoid lint. Lint is mostly found in those furnaces that are located in a room since it uses the air in the room, which has limited oxygen to allow full combustion.

It is imperative to clean furnaces and eliminate any traces of dirt. Dirt is regarded as harmful because it reduces its efficiency, and prompts high drains of fuel usage. You do not need plumbing skills to clean or maintain one. Other parts that you should take care of include the blower, motor, filter and power cord. For example, always ensure that all cords are connected appropriately to prevent short circuit. It is important to maintain plumbing machines for long in order to avoid repair and replacement expenses on your furnace.

If you feel this is beyond your skill level and you are not comfortable preforming these tasks then it is recommended that you set up a regular maintenance schedule with a reputable Kelowna furnace cleaning company in the city you live in. If your home uses a boiler for radiant heat instead of a forced air furnace, no need to worry because most contractors that handle furnace repair also service boilers.

Furnace Cleaning Tip

How To Find Professional AC Repair

Hiring a professional AC repair company is a very important decision that home owners need to make this summer. When it comes to your house, one of the most vital systems is your hvac system. For this reason it is necessary to regularly have your system checked by a professional ac repair work firm.

Any credible company concentrating on 24 hr air conditioning repair will certainly have the ability to provide you along with the routine maintenance your system has to try to keep running at a the best possible level. They will likewise be able to give you assistance on exactly how you can keep your system functioning effectively as well.

HVAC Systems

The hvac system is what takes care of the central air within your home. For this reason it’s important that it is consistently cleaned and examined. This will enable your system to operate successfully and keep your month-to-month costs down. It’s likewise crucial to take care of any kind of issues promptly by getting a cooling repair work business to come check out your system and see what the problem is.

Selecting Professional AC Repair People

There are some things you can do that could help keep your system going effortlessly between maintenance times. As long as your system is operating effectively and does not call for repair then there are some things you could do to keep it running hassle-free. This includes keeping your air filters tidy and changing them regularly. You likewise want to make sure that your condenser is constantly well-maintained– keeping it clear from fragments.

Your air return grill is likewise important; you want to make certain there is no dust as this is the air that will come back into your home. If you have an outdoor system you want to make sure it is calibrated correctly as this will assist optimize your systems efficiency. By keeping these things in mind and seeing that your system receives regular maintenance your system ought to last a very long time and continue to keep your place comfy.

AC Repair Maintenance

Every concerned homeowner will want to have the latest technology to help maintain the quality of the air in your home. This is especially valuable in the Flu Season. When systems are set up to aggressively combat any sources that can lead to sickness you have a healthier home.

We understand how important it is to maintain your AC system and keep the ducts clean and open, with proper maintenance harmful gasses, viruses, and odors can be reduced by up to 99%!

For just pennies on the dollar you and your whole family can be protected from illness causing microorganisms!

HVAC systems that aren’t properly maintained can actually cause more harm than good. Due to the nature of their inner workings they can be the perfect breeding ground for harmful microorganisms like mold and other allergens. We check systems and make sure they’re working properly and are cleaned properly to prevent this from happening. We want only the cleanest air for our customers!