Frequently Asked Questions

Furnaces are rated by the Annual Fuel Utilization Efficiency (AFUE) ratio, which is the percent of heat produced for every dollar of fuel consumed.

Like the miles-per-gallon rating on your automobile, the higher the AFUE rating, the lower your fuel costs. All furnaces manufactured today must meet at least 78% AFUE. If your furnace is 10 to 15 years old, it very well may fall below the current furnace minimum and waste energy.

This doesn't mean that you should only select a furnace based on its AFUE rating. The efficiency rating is just one factor to consider when looking for a new furnace.

Furnaces use electricity to run fans and motors. The amount of electricity used varies greatly depending on the type of furnace. Be sure to check electricity usage prior to making a purchase decision.

The term "variable speed" refers to the furnace's indoor blower motor, which moves at different speeds to precisely control the flow of heated and cooled air throughout your home. Better airflow control has several benefits:

Electrical efficiency
Variable speed motors can actually save you money on your energy bills, as they consume less electricity than standard motors.

Cooling efficiency
Variable speed technology also means you will gain heating efficiency or AFUE.

Zoning
Variable speed motors are excellent for zoning, which allows you to customize your comfort in different areas of your home and control your energy bills.

Air quality
A variable speed motor can also help clean the air in your home. When the fan is in constant operation (indicated by the "Fan" setting on your thermostat), the motor will continue to slowly circulate air, allowing filters to capture more contaminants.

Humidity control
A variable speed motor combined with a programmable thermostat allows you to control the amount of humidity in your home for improved indoor air quality and comfort.

A heat pump is an all-in-one heating and air conditioning system that works year-round to keep you comfortable.

During warmer months, a heat pump works as a normal air conditioner. It extracts heat from inside the home and transfers it to the outdoor air. In colder weather, however, the process reverses—the unit collects heat from the outdoor air and transferring it inside your home.

Even when the air outside feels extremely cold, the air still contains some heat. The heat pump pulls the heat from this cold outdoor air and sends it inside to warm your home. When there's not enough heat in the outside air to meet the demand of the thermostat setting, an electric heater supplements the outdoor air to warm the home. Extremely efficient, this process produces two to three times more heat than the energy it uses.

Also, a heat pump can be an effective add-on option to use in conjunction with an existing gas furnace. With this dual-fuel option, the two systems share the heating load, but never function at the same time. Each system operates when it is most cost effective. The heat pump will be the primary heating and cooling system. However, when the temperature drops below the heat pump's ability to operate as efficiently as the gas furnace, the gas furnace will take over until the temperature rises enough for the heat pump to operate more efficiently.

Two-stage heating means the furnace has two levels of heat output: high for cold winter days and low for milder days. Since the low setting is adequate to meet household-cooling demands 80% of the time, a two-stage unit runs for longer periods and provides more even heat distribution.

Longer, low-capacity operation has many advantages:

Consistent comfort
Two-stage heating eliminates the temperature swings associated with standard furnaces, regulating temperature to within as little as one degree of the thermostat setting.

Quiet operation
Two-stage furnaces start in the first stage, when the amount of heat required is lower, instead of reaching full capacity all at once. That means there's no sudden "kick" or blast of air.

Improved air filtration
Low-speed operation allows your filters to capture more contaminants (because air is constantly passing through them), so you can breathe easier.

Efficient performance:
Because the furnace operates mostly in its lower-capacity first stage, it burns less fuel than a standard furnace that always runs at full capacity and shuts off when the heating demand has been met.

Furnace technology has advanced significantly in recent years, raising concerns over chimney use. As a result of changing technology, many existing masonry chimneys aren't able to meet the specific demands of new furnaces.

There are several reasons for this furnace-chimney incompatibility. First, the size of the chimney can be an issue. Modern, higher-efficiency furnaces transfer more heat into your home and less heat up the chimney than older, less-efficient units. While this means more efficiency for your energy dollar, it also means that the existing chimney might be too large for the new furnace. The result could be improper ventilation of flue products, which can cause condensation problems inside the chimney.

Other considerations include chimney height and location, proper lining and condition of the chimney. Building codes must also be kept in mind to ensure proper draft in the chimney for adequate ventilation.

Furnace technology has advanced significantly in recent years. Modern furnaces are designed to provide more even and efficient heating than past furnaces, which can impact both how your system operates and what you notice about your system.

To better regulate temperatures and airflow, modern furnaces move more air over the heat exchanger than older furnaces. The air that comes out of your furnace registers may not seem as warm as the air from your old furnace, but overall airflow is improved. Better airflow means higher comfort.

Also, new furnaces are designed to integrate with high-efficiency air conditioners, so furnace blowers are more powerful to accommodate add-on cooling. Since cold air is much heavier than warm air, your system needs an extra boost from the blower to deliver cool air throughout your home. If you have an older home, this performance boost could produce unfamiliar sounds because air duct systems were originally designed for heating only. To minimize sound levels, choose a variable speed product which automatically changes speeds to meet the airflow needs of both heating and cooling cycles.

The answer is most likely YES, but this is mainly due to four main reasons:

1. Matched system design
   All outdoor cooling units are specifically designed to work with matched indoor units for optimum efficiency and performance. Air conditioner and heat pumps may "work" with other indoor units, but the result is a definite compromise in overall system performance.
2. Design advances
   In recent years, indoor blower coil units have undergone numerous design advances—especially in the areas of air handling performance, filtering efficiency and operating sound levels. A new outdoor unit will also include the latest design advances.
3. Higher cooling and heating efficiency
   The cooling and/or heating efficiency rating assigned to a given air conditioner or heat pump is based on matched system performance. While you may gain higher efficiency by replacing only the outdoor unit, the efficiency levels (and savings) will not be as high as with a matched system.
4. Equipment age
   If an air conditioner or heat pump outdoor unit is 10 years old and needs to be replaced, the indoor unit is just as old and has been subjected to the same amount of wear and tear. Replacing both units means you won't have to replace the indoor unit in a short time you'll have years of service from both units.

New warranty
A new unit also gives you a new product warranty. Replacing the indoor unit at the same time as the outdoor unit gives you added peace of mind, knowing the new warranty covers the entire system. Cost savings

At first, replacing only an air conditioner or heat pump outdoor unit may appear to be a bargain. That is, until you consider the lower efficiency, decreased reliability and high cost of ownership associated with single-unit replacement. It may cost more to replace an entire system, but this gives you more efficiency, reliability and comfort.

Simply put, all Heat Pumps in northern climates [below 0 degrees Celsius] need a supplemental heating source. Usually it is in the form of electric resistance heating. This is an all-electric Heat Pump. It can be a gas, oil, or hot-water back-up system as well. The supplemental heat is also referred to as "second-stage" or "back-up" heating, "first-stage" being the Heat Pump only. The supplemental heat is also what is used as the Emergency Heat.

Different systems have different ways of determining when the second-stage comes on to assist the heat pump but it is always done automatically. So the two stages will work together in the colder months and it is not necessary to switch your thermostat to Emergency Heat. Now we know what supplemental heat is and that it is also used for Emergency Heat.

The Emergency Heat switch on a Heat Pump thermostat confuses many people. The fact of the matter is that most people don't seem to understand exactly what Emergency Heat is and when they need to use it. Many people think that Heat Pumps don't work in cold weather and they are supposed to use the emergency heat whenever it gets really cold... Wrong!

An air conditioner seems as if it cools your home's air, but it actually makes your home less warm by removing heat from the indoor air and transferring that heat to the outdoor air.

Heat is extracted from the home by passing indoor air across a refrigerant coil in the indoor unit. Refrigerant lines then carry the heat to the outdoor unit, where it is released into the outside air. The cooling cycle continues until the indoor temperature reaches the thermostat setting.

SEER (Seasonal Energy Efficiency Ratio) is a system for rating the efficiency of cooling equipment. The higher the SEER rating, the less your unit will cost to operate.

HSPF (Heating Seasonal Performance Factor) is a measurement similar to SEER, but it measures the efficiency of the heating portion of a heat pump.

Two-stage cooling means the air conditioner or heat pump has a compressor with two levels of operation: high for hot summer days and low for milder days. Since the low setting is adequate to meet household-cooling demands 80% of the time, a two-stage unit runs for longer periods and produces more even temperatures.

Longer cooling cycles also translate to quieter, more efficient operation and enhanced humidity control. Compared to a single-stage unit, a two-stage air conditioner or heat pump can remove twice as much moisture from the air. This is important because when moisture levels are high, there's a higher potential for mold and other pollutant problems.

"Variable speed" refers to the fan motor inside the air handler—the indoor part of an air conditioner that moves cooled or heated air throughout the ductwork of your home. An air handler is usually a furnace or a blower coil.

Unlike conventional single-speed motors, a variable speed motor runs at a wide range of speeds to precisely control of heated and cooled air throughout the home.

Better airflow control has several benefits:

Electrical efficiency
Variable speed motors can actually save you money on your energy bills, as they consume less electricity than standard motors.

Cooling efficiency
Variable speed technology also means you will gain air conditioning efficiency or SEER.

Zoning
Variable speed motors are excellent for zoning, which allows you to customize your comfort in different areas of your home and control your energy bills.

Air quality
A variable speed motor can also help clean the air in your home. When the fan is in constant operation (indicated by the "Fan" setting on your thermostat), the motor will continue to slowly circulate air, allowing filters to capture more contaminants.

Humidity control
A variable speed motor combined with a programmable thermostat allows you to control the amount of humidity in your home for improved indoor air quality and comfort.

The only reliable way to determine the size that best matches the needs of your home is to have your local Lennox dealer perform a load calculation, which takes into account the square footage of your house, the insulation value of your windows, the amount of insulation in your walls and roof and many other factors.

A heat pump is an all-in-one heating and air conditioning system that works year-round to keep you comfortable.

During warmer months, a heat pump works as a normal air conditioner. It extracts heat from inside the home and transfers it to the outdoor air. In colder weather, however, the process reverses—the unit collects heat from the outdoor air and transferring it inside your home.

Even when the air outside feels extremely cold, the air still contains some heat. The heat pump pulls the heat from this cold outdoor air and sends it inside to warm your home. When there's not enough heat in the outside air to meet the demand of the thermostat setting, an electric heater supplements the outdoor air to warm the home. Extremely efficient, this process produces two to three times more heat than the energy it uses.

Also, a heat pump can be an effective add-on option to use in conjunction with an existing gas furnace. With this dual-fuel option, the two systems share the heating load, but never function at the same time. Each system operates when it is most cost effective. The heat pump will be the primary heating and cooling system. However, when the temperature drops below the heat pump's ability to operate as efficiently as the gas furnace, the gas furnace will take over until the temperature rises enough for the heat pump to operate more efficiently.

The answer is most likely YES, but this is mainly due to four main reasons:

1. Matched system design
   All outdoor cooling units are specifically designed to work with matched indoor units for optimum efficiency and performance. Air conditioner and heat pumps may "work" with other indoor units, but the result is a definite compromise in overall system performance.
2. Design advances
   In recent years, indoor blower coil units have undergone numerous design advances—especially in the areas of air handling performance, filtering efficiency and operating sound levels. A new outdoor unit will also include the latest design advances.
3. Higher cooling and heating efficiency
   The cooling and/or heating efficiency rating assigned to a given air conditioner or heat pump is based on matched system performance. While you may gain higher efficiency by replacing only the outdoor unit, the efficiency levels (and savings) will not be as high as with a matched system.
4. Equipment age
   If an air conditioner or heat pump outdoor unit is 10 years old and needs to be replaced, the indoor unit is just as old and has been subjected to the same amount of wear and tear. Replacing both units means you won't have to replace the indoor unit in a short time—you'll have years of service from both units.

New warranty
A new unit also gives you a new product warranty. Replacing the indoor unit at the same time as the outdoor unit gives you added peace of mind, knowing the new warranty covers the entire system.

Cost savings
At first, replacing only an air conditioner or heat pump outdoor unit may appear to be a bargain. That is, until you consider the lower efficiency, decreased reliability and high cost of ownership associated with single-unit replacement. It may cost more to replace an entire system, but this gives you more efficiency, reliability and comfort.

The SunSource® Home Energy System reduces the amount of electricity needed from your utility provider to put you in control of your utility bills. This energy-saving system harnesses solar-energy and uses it first—before using electricity from the utility company—to power your air conditioner or heat pump. The solar power that's collected can also operate other appliances and electronics when the heating and cooling system is not in use. What's more, if the SunSource system generates more solar power than is needed, that power will be sent back to the utility company, possibly entitling homeowners to a credit.

Solar power has a number of substantial advantages, from economical to environmental:

Readily available. Electricity generated from sunlight is free and limitless.

Significant energy savings. A SunSource® Home Energy System with as few as one solar module can save you money on your monthly utility bills. The U.S. federal government and some states provide tax credit for renewable-energy systems. Depending on where you live, you may also be eligible for incentives through your utility company. To find out what incentives are available in your area, visit dsireusa.org

Virtually no environmental impact. Solar is a fast-developing renewable energy source because it produces no air pollution or hazardous waste. By comparison, electricity generated by power plants produces carbon dioxide emissions that are believed to contribute to climate change and pollution.

Can be expanded over time. The SunSource system gives you the flexibility to start small and add more roof modules at a later date for greater energy savings.

The modules are made of tempered glass and are laminated to a resilient substrate. They are rugged, durable, and weather-and-impact-resistant.

The hardware that mounts the modules to your roof allows them to integrate nearly flush with the surface for a discreet appearance that does not detract from the overall appeal of your house.

Your system will not work at night because the solar modules need sunlight to produce power. Solar modules will still produce power on cloudy or overcast days, but at a reduced level.

We stand behind the Lennox name and the quality that has made us a global leader in home comfort. Because the SunSource® Home Energy System is backed by Lennox, you can take comfort knowing it's built to exacting standards. Our warranties are designed to give you added peace of mind:

Solar-ready heat pumps and air conditioners from the Dave Lennox Signature® Collection include a 10-year limited warranty on the compressor and covered components.

Solar modules include a 5-year limited warranty against defects from faulty workmanship or damage to the surface. The modules have a 12-year limited performance guarantee that covers a power output of less than 90%; a 25-year limited performance guarantee applies to a power output of less than 80%.

Microinverters include a 15-year limited warranty against defects in workmanship and materials.

The number of modules you need depends on several factors, including the size of your home, angle of your roof and so on.

SunSource systems are suitable for almost any location in North America and are adaptable to almost any roof type.

In the event of a power outage caused by a storm or some other problem, the SunSource system will shut off. Once power is restored by your utility company, the system should turn back on automatically along with lighting, appliances and other household electronics.

A qualified Lennox Home Energy Consultant can install the system in one day once the plans are approved. The system can be running in as little as a few hours, depending on the amount of solar modules installed.

Your air filter is located in either the blower compartment of your furnace, in an attached filter case, or in a wall-mounted return air grille.

Every month, you should inspect or clean your air filter, or replace it if necessary, to keep your equipment running at peak efficiency.

You can purchase replacement filters from Custom Cooling Solutions. Some after-market filters are not recommended by Lennox for use with Lennox heating and cooling equipment because they may be too restrictive and cause system malfunctions.

According to the Environmental Protection Agency (EPA), your exposure to air pollutants can be up to 100 times higher indoors than outdoors. The American Lung Association estimates that most people spend 90% of their time indoors, so clean indoor air is very important.

Many everyday household items contribute to poor indoor air quality. Compounds found in carpeting, furniture, upholstery and drapery fabric consistently emit gas or fumes. Other sources of pollutants can include, but are not limited to, cleaning agents, paints and personal care products.

Also, newer homes that are tightly sealed for energy efficiency tend to limit air circulation, which can contribute to a buildup of contaminants. Likewise, things like weather stripping and storm doors keep stale air in and fresh air out.

There are five basic strategies for outsmarting indoor air pollution:

Identify the problem
The first step toward better indoor air is to identify the types of pollutants present in the home. The best way to do this is to schedule an in-home air-quality test with your local Lennox dealer. Reduce concentrations of particles and bioaerosols

Routine cleaning and housekeeping helps reduce indoor air pollutants, but these simple fixes are not cure-alls. Some contaminants are so small that they may escape through the vacuum or never land on a surface. Lennox HEPA filtration systems, electronic air cleaners, high-efficiency air filters capture even the smallest of particles and bioaerosols. Reduce or eliminate chemical vapors and odors

Chemical vapors and odors can come from many different sources inside and outside the home. Once inside the home, these potentially toxic pollutants circulate through the ductwork, entering every room and living space. A Lennox air purification system removes and destroys 50% of household chemical vapors and odors within 24 hours.

Ventilate Your Home
Today's modern homes are well-insulated and sealed to conserve energy, which means airborne pollutants have no way to escape. Ventilation systems help remove particles and bioaerosols by exchanging stale, recirculated indoor air with fresh, filtered outside air.

Control Temperature and Humidity
Improper humidity levels and high temperatures can actually increase concentrations of particles and bioaerosols. Programmable thermostats regulate moisture levels and temperatures to improve indoor air quality and enhance comfort.

You may have tried to get rid of odors in your home by spraying air fresheners or lighting candles. The problem with these methods is that they only mask the odors—they don't get rid of them. In fact, they may even cause further contamination of the home due with chemical ingredients.

Improve ventilation
What causes the lingering odors? Sometimes, poor ventilation in a home causes unpleasant odors. Moisture condensation on walls or windows and stuffy air are signs of poor ventilation. A qualified service technician can inspect your home comfort system to determine if this is indeed the problem, and the technician can also inform you whether or not your equipment is working properly.

Purify the air
Bacteria, dust mites, animal dander, cat saliva and mold may also be roots of your home's odor problem. You can reduce these odor-causing contaminants with a germicidal (UV) light, which inhibit the growth of biological contaminants, sterilizing surfaces in the HVAC system. Germicidal lights are designed to work with your home comfort system.

Activated carbon and microbiocide-treated filters can also purify your home's air. Both the carbon and the microbiocide-treated filters remove odor and kill bacteria. The carbon filters are more effective at removing odor, and the microbiocide-treated filters trap bacteria as the air is pulled through, which inhibits biological contaminants from growing.

Electronic air cleaners clean the air by taking recirculated air and passing it through a prefilter that traps large pollutants. Then, ionizing wires give a positive electrical charge to remaining particles. The particles are collected by a negatively charged collecting section. Pollutants pass through an optional carbon filter that absorbs unwanted odors.

Allergies and asthma are two health problems that can be helped with clean indoor air. When airborne irritants are removed, allergy and asthma sufferers often find relief from their symptoms. Even healthy people who have never suffered from allergies can benefit from clean air. Dust, smoke and other particles float around in the air, causing your drapes and furniture to gather dust. By removing airborne dust particles, you reduce the amount of exposure your respiratory system has to them.

At one time, it was possible to achieve natural ventilation in our homes by merely opening a window. However, with the concern for energy efficiency in recent years, we have been busy making homes "tighter" from an energy standpoint. Armed with weather stripping and caulk guns, we have eliminated air leaks from our homes. Unfortunately, that means contaminants have no way to escape.

Pollutants in your home's air can cause poor indoor air quality, which in turn may cause dizziness and headaches, plus aggravate allergies and asthma. Ventilation systems that help remove contaminants by exchanging stale, recirculated indoor air with fresh, filtered outside air.

With central heating, people are confined indoors with unnaturally dry air for many months each year. Humidifiers help to keep comfortable levels of moisture in the air, which is essential for your respiratory health.

Whole-house humidifiers work like old-fashioned room humidifiers: They put moisture into the air, making harsh, dry air easier to breathe. And whole-house humidifiers use water mists instead of hot steam, which keeps the entire house at the desired humidity level - no more carrying a humidifier from room to room in the winter.

The amount of sound generated by a heating or cooling system can have a significant impact on comfort. Inside the home, a low sound level means no sudden blast of air at startup and smooth, vibration-free operation. Outside the home, low sound levels help you keep the peace with your neighbors. This is particularly important, given that many communities have noise ordinances.

Most heating and cooling systems manufactured today are quieter than those produced in past years. But there is still significant variance in sound rating ratings among these products.

Lennox designs each air conditioner and heat pump to be as quiet as possible. Through extensive testing, Lennox has come up with many features that, either alone or in combination, make our air conditioners and heat pumps some of the quietest available.

Insulated compressor compartments, discharge mufflers and patented fan designs work to soften the sound of a hard-working, high-efficiency compressor. Top-panel orifices, compressor wrappers and indoor blowers are all designed to further promote smooth, quiet airflow.

You wouldn't buy a brand-new car and expect to never have to put air in the tires, change the oil and check out any unusual noises, would you? In the same way that an automobile requires periodic maintenance for optimal performance, a home comfort system should be regularly inspected by a qualified technician.

Covering the unit is not necessary, especially if you have a heat pump that runs all year long. In fact, covering an entire unit may actually trap moisture.

Heating and Air Conditioning equipment should be serviced at least once a year. The best scenario is to have the heating system checked in the Fall and the air conditioning checked in the Spring. Oil-fired equipment should definitely be cleaned and serviced annually.

A zoning system is designed for the many ways you use your home. Maybe you're caught up in family "thermostat wars?" Or perhaps you have unoccupied areas that do not need conditioning? A zoning system allows you to divide your home into separate areas, giving you the comfort and control you've always wanted.

The main benefits of residential zoning are:

Comfort
Zoning meets the specific temperature and airflow requirements of one area, without affecting other areas.

Efficiency
A properly designed zoning system can save you hundreds of dollars in energy costs each year.

Control
Zoning divides the home into different areas and comfort into different levels, giving you more choices and control than ever before.

Quiet Performance
When integrated with variable speed and/or two-stage HVAC systems, zoning allows your heating and cooling equipment to deliver peak performance and efficiency without continually operating at peak capacity. Lower speeds mean lower sound levels.