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A furnace AFUE rating provides you with a single metric to assess how much heat that unit will generate over an average year versus the amount of energy it will consume to do it. Short for Annual Fuel Utilization Efficiency, the rating for a specific unit is determined by lab tests and is usually prominently displayed on the furnace’s yellow EnergyGuide sticker. It gives consumers a quick, at-a-glance method to comparison shop among different makes and models. The Annual Fuel Utilization Efficiency percentage doesn’t tell you everything you need to know about a furnace, but it does serve as a baseline for estimating energy efficiency.

In the 1970s, gas-fired furnaces typically had AFUEs around 60 percent. That means 40 percent of the energy contained in the natural gas or heating oil was lost in the combustion process and did not contribute heat to warm your home. Most of that energy went up the vent in the form of hot combustion gases. Today, the minimum allowable Annual Fuel Utilization Efficiency rating is 78 percent. Mid-range conventional furnaces have ratings in the range between 80 and 83 percent. High-efficiency furnaces, known as condensing furnaces, incorporate a secondary heat exchanger to extract spare heat from combustion gases. This boosts the rating of these units to 90 percent and above.

Two things to remember:

  • AFUE should be considered in conjunction with other issues such as the cost of fuel. Because electric furnaces don’t utilize combustion to generate heat, these units typically have AFUE ratings above 90 percent. However, since electricity generally costs substantially more than gas, a gas-fired furnace with a lower AFUE is usually the more cost-efficient choice.
  • Furnace efficiency is expressed by factors other than the Annual Fuel Utilization Efficiency rating. The furnace blower fan's electrical consumption isn’t included when calculating the rating. Yet, it makes a substantial contribution to furnace operating cost. Optional variable-speed ECM blowers that reduce electricity use as much as 75 percent less also help reduce utility expenses.

For more information about the importance of the AFUE when shopping for a furnace in the Richmond area, contact us at Gilman Heating & Cooling.

Consider the possibility of installing a boiler heating system instead of a furnace in your new Richmond area home. Boiler heating offers several advantages over furnaces in terms of efficiency, ease of operation and home comfort. Refer to this short guide so you know the right questions to ask your heating contractor as you design your new living space.

The main furnace versus boiler difference is in the heat transfer medium. Boilers use hot water and furnaces use hot air. The answer to "how do boilers work?" is fairly simple: A boiler system features a burner which heats water in a storage tank, and a circulating pump that moves the hot water through radiators or floor heating loops. A furnace heats air and uses a blower to force the hot air into the home's ductwork.

Advantages and Disadvantages of Boiler Heating

  • Cost - Boiler systems cost a little more to install than furnace systems, but the extra cost will be recovered over time due to higher energy efficiency.
  • Comfort - Boiler heating keeps a house more comfortable than forced air heating. The radiant heat from hot water doesn't dry the air out like the convection heat supplied by a furnace. With floor-loop hydronic systems, the floors stay warm and cozy, whereas a furnace heats the air above the floors and the floors remain cold.
  • Ease of operation - Boiler systems are easier to maintain than furnace systems. There are no filters to change in a boiler system and there are no supply and return air ducts to have to keep unobstructed and in balance.
  • Efficiency - Modern boilers and furnaces have comparable annual fuel utilization ratio (AFUE) ratings—the ratio of heat supplied by the boiler or furnace to the fuel consumed by the burner. But hot water systems are more efficient beyond the boiler than forced air systems are beyond the furnace, since less energy is lost in the piping than in the ductwork. It's also easier to install and operate zoning systems with boiler heat.

For more information on boiler heating, or any other home comfort questions, contact the pros at Gilman Heating & Cooling. We're proud to service Richmond area homes.

Now that fall has arrived, you'll want to take some time to schedule your annual heating system or furnace tune-up if you haven't already. A yearly inspection by a professional is an important part of every homeowner's routine for numerous reasons, including maintenance of  your system warranty, avoidance of problems down the line when the weather is frigid and, most importantly, the safety of your family. Taking this simple step is something you'll be glad you did.

What's Involved in a Furnace Tune-Up?

A quality technician will take the time to check out many aspects of your heating system including:

  • Thermostat settings
  • Electrical connections
  • Moving parts
  • Condensation drain
  • System controls

It's important to ensure that the thermostat settings are working correctly, keeping your home at a constant temperature, saving you money. Checking the electrical connections decreases the potential for any safety issues and increases your system's overall life. Keeping the moving parts lubricated will make for a more efficient-running furnace and decrease your energy consumption. If your condensation drain is clogged, it can cause big problems such as water leakage in your home and high indoor humidity.

It's also imperative that your technician inspects specific items and components in gas systems during the fall furnace tune-up. If your gas connections are not operating properly, it can be very dangerous.

What You Can Do Yourself

There are some steps you can take on your own to increase your furnace life. Once a month, you'll want to inspect the condition of your system's air filter. If dirty, it's easy to clean or replace. Our technicians will be pleased to show you how to do these things and answer any questions. Keeping up with regular maintenance will help to extend the life of your system and make it more efficient; however, personal maintenance is no substitute for a professional inspection. Only trained professionals know what to look for and how to repair the complex parts of your furnace.


Please give us a call at Gillman Heating & Cooling to set up your furnace tune-up today. We serve Richmond, Ashland, Henrico, Chesterfield, Hanover and Glen Allen.



The changing of the seasons offers the perfect opportunity to clean up, make repairs, and generally get your home in good order so you can enjoy the best home comfort and energy efficiency during the coming months. Here are some regular tasks that should be part of your fall home maintenance routine before the colder temperatures really move in. Check your insulation and weatherproofing. Look for daylight or feel for a draft with your hand, going around to all windows and doors in the home. Consider replacing or upgrading weatherstripping and caulk wherever necessary. Don’t forget basement windows and other less obvious areas. Heating and cooling make up about half of your energy bills, so  weatherization represents a vital part of fall home maintenance. Take care of your air conditioning system. You should winterize your air conditioner as soon as you won’t be using it. Place approved tarps over outdoor units and bring window units inside. The windows will help retain more heating if you remove the window unit. Reverse ceiling fans. Don’t forget to change the direction your ceiling fans rotate so that you can spread warm air downward during the heating months. Get your humidifier situation in order. Having a humidifier during heating season greatly improves home comfort. Clean your humidifier or consider getting one if you do not have one already. Clean it regularly so that it can better remove allergens and pathogens in the air to improve your indoor air quality. Take care of wood stoves and fireplaces. Have a chimney sweep clean your chimney and check on any leaks or damage. By taking a moment to maintain your home and its heating and cooling equipment you’ll be able to enjoy better air at home while minimizing your energy bills. Like spring cleaning, consider fall maintenance to prepare for cold weather ahead. For help with fall home maintenance in your home, contact us at Gilman Heating and Cooling and ask how we can help. We’ve been serving the greater Richmond area since 1917.  

Perhaps you spend a lot of time in your garage working on the car, playing around with power tools, or maybe even hosting a table tennis tournament. Or maybe the recent college grad in your family is moving back in with the parents, but you turned his bedroom into an office when he left.   There are plenty of good reasons to spend time in the garage, and air conditioning a garage can be crucial to enjoying your time there. Ductless systems offer easy and efficient solutions for air conditioning your garage.   Ductless systems don’t require extensive duct space because the compressor needs only a little room on the wall. The technology behind ductless air conditioners allows the necessary machinery to have a layout very different from window units or outdoor units.   Key advantages of ductless systems include:

  • Powerful cooling ability
  • Higher efficiency than other solutions
  • Flexible options to suit your space
  • Flexibility for air conditioning a garage or other individual rooms
  • Supplemental cooling for rooms that don’t get cooled easily

  Ductless systems can often cost more than window units, but those are not an option in many garages. Also, the cost of a ductless air conditioner may be mitigated by the fact that you don’t have to do additional ductwork in order to install the unit. There are many questions about air conditioning that we can answer for you to help determine your best options.   If you want to convert a garage or if you like spending time there, you should ensure that you and your family can feel comfortable and breathe healthful air there. You may have thought that air conditioning your garage was not an option, but ductless air conditioning units can cool the room perfectly.   For help figuring out how and where to install air conditioning for your garage, get in touch with us at Gilman Heating & Cooling. We’ve been proudly serving the greater Richmond area since 1917.