Frequently Asked Questions
Here you will find information that should help to answer some questions that you may have concerning heating and air conditioning in your home or office. We will explain what a heat pump is, how your equipment works, energy ratings, new refrigerant, as well as various other topics that tend to be confusing to homeowners.
How does an air conditioner work?
Air conditioning includes both the cooling and heating of air. It also cleans the air and controls moisture levels. An air conditioner is able to cool a building because it removes heat from the indoor air and transfers it outdoors. A chemical refrigerant in the system absorbs the unwanted heat and pumps it through a system of piping to the outside coil. The fan, located in the outside unit, blows outside air over the hot coil, transferring heat from the refrigerant to the outdoor air.
Your air conditioning system has four mechanical components – a compressor, an expansion valve, an evaporator coil and blower, and a chemical refrigerant. A central air conditioning unit operates by means of a split system. That is, it consists of a “hot” side, or the condensing unit – including the condensing coil, the compressor, and the fan – which is situated outside your home, and a “cold” side that is located inside your home. The cold side consists of an expansion valve and a cold coil, and it is usually mounted on your furnace or air handler. The furnace blows air through an evaporator coil, which cools the air. Then this cool air is routed throughout your home by means of your duct work. For more information on the compressor, condenser coil, expansion valve, and evaporator coil, see our HVAC terms.
A bigger air conditioner will cool my home better, right?
Wrong! When considering the purchase of a new air conditioner for your home or office, consider the fact that today’s best air conditioners use 30% to 50% less energy to produce the same amount of cooling than air conditioners from the mid-80’s. A larger air conditioner will not necessarily provide the best cooling. Many companies will not spend the time to accurately size your equipment, but it is absolutely critical. A larger air conditioner costs more initially. It will cycle on-and-off more frequently which will drastically lower efficiency. Frequent cycling also causes large temperature swings which decrease your comfort. In humid areas such as the Ohio River Valley, moisture removal is critical. Excessive cycling reduces moisture removal and wears out parts and components much more quickly. When all of these factors are combined, it means more electricity usage and shorter equipment life, which costs you more money.
What are the benefits of two-stage cooling?
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. As an added benefit, many two-stage compressors use the new R410A refrigerant, which meets US government standard for environmental safety.
When replacing the outdoor unit of an air conditioner or heat pump,
should the indoor unit also be replaced?
We highly recommend it; here are the reasons why! All outdoor air conditioning and heat pump units are specifically designed to work with matched indoor units for optimum efficiency and performance. While new air conditioner or heat pump units may “work” with your existing indoor unit, the result is a definite compromise in system performance. The cooling and/or heating efficiency ratings that are advertised for an air conditioner or heat pump are based on their performance as part of a matched system. Longer equipment life will likely also result because all components operate as they we designed to. At first glance, replacing only the outdoor unit may appear to be a bargain, but decreased efficiency and reliability is not such a bargain after all. Replacing an entire air conditioning or heat pump system costs more initially, but you get more efficiency, reliability, and comfort in the long run.
Should I be concerned about the new energy efficiency standards?
Federal regulation has raised the energy efficiency standards for air conditioners and heat pumps. A minimum of 13 SEER is required for air conditioners and 13 SEER/7.7 HSPF for heat pumps. Previously, ratings were only required to meet 10 SEER. This increase in energy efficiency creates significant environmental benefits as well as important economic benefits. For example, when compared with older, less efficient equipment, air conditioners and heat pumps with higher SEER ratings can save you hundreds of dollars each year on your utility bills.
What can you tell me about air conditioning refrigerants?
Refrigerants are what make air conditioning possible. Contained within the coils of your system, these agents make it possible to cool and dehumidify indoor air. Today, there are several types of refrigerants used in air conditioning systems. The most common is R22, which will be phased out over the coming years in response to international environmental concerns. Though the transition away from R22 is just beginning, Prudential and Lennox are one step ahead by offering a full line of products that use a more responsible, chlorine-free refrigerant, R410A. R410A is better suited for use in higher-efficiency equipment because you get a higher heat transfer rate than with R22.
How does a furnace work?
A furnace works by drawing air inside a heat exchanger, where it is warmed with a flame of natural gas. A blower sends the warm air through the house via your metal ducts. It enters the room through a register in the floor or wall. Indoor air is circulated continuously through the system, so a furnace filter is used to contain dust, pollen, and other airborne particles.
What is a heat pump and how does it work?
A heat pump is an efficient method of cooling your home in the summer and warming it in the winter. It works by moving existing heat from one area to another. A condenser absorbs heat from the outdoor air (even the coldest air contains some heat) and transfers it to an indoor coil. During the summer, the process is reversed to cool and dehumidify your home. One advantage of a heat pump is that it provides both heating and cooling capabilities in one unit. Like a furnace, they use filters to reduce airborne particles and keep the unit clean.
What is a dual fuel system?
A dual fuel system combines your electric heat pump with your indoor gas furnace to share the heating load of your home. Each system will operate when it is the most cost effective heating method. In the summer, your heat pump will cool your home. It will also serve as your primary heat source in the winter. However, when the temperature drops below the heat pump’s set point, your furnace will take over until the outdoor temperature rises enough for your heat pump to operate more efficiently again.
What is a variable speed furnace or air handler?
Inside your furnace or air handler is an electric motor that drives the indoor blower. In most standard systems, it runs at only one speed – full capacity – and is either on or off. A variable speed motor, however, automatically varies its speed based on your home’s heating and cooling requirements. It ramps up to maximum speed slowly instead of coming on full throttle all at once. This means no more sudden blasts of air – just a gentler, more even airflow. Also, since it runs as a lower speed most of the time, there is a lot less noise and cost to operate.
What are furnace energy ratings?
Furnaces are rated by the Annual Fuel Utilization Efficiency (AFUE) ratio, which is the percent of heat produced for every dollar of fuel consumed. AFUE works a lot like the miles-per-gallon rating on your car – the higher the rating, the lower your fuel costs. All furnaces manufactured today must have an AFUE ratio of at least 78%. If your furnace is 10-15 years old, it very well may fall below the current furnace minimum and waste energy.
What’s the advantage of two-stage heating?
Traditional furnaces are designed to operate only at one level – high. No matter what the temperature is outside, they run at full capacity. Furnaces with advanced two-stage technology make the distinction between mild and extreme weather, delivering the level of heating output necessary to maintain optimal comfort conditions inside your home. The first stage operates the furnace at about 68% of its heating capacity. Your furnace will adjust automatically should the outdoor temperature drop and switch to the second stage to meet the comfort demands of your home. It’s like having two furnaces for the price of one, and you don’t have the hassle of constantly adjusting your thermostat. A two-stage furnace can provide optimal comfort within your home, despite the changing weather conditions outside. If you want and expect high-level performance from your home comfort equipment, then a Lennox two-stage furnace is the right choice for you.
Why should I zone my house?
To keep all areas of your home comfortable, no matter what the weather! No longer must you have hot or cold rooms, or pay to heat or cool areas of your home that you rarely use. Zoning has come a long way in recent years, and it is now efficient, easy to install and flexible enough for any home.
Why should I choose Lennox products?
Lennox has long enjoyed a reputation for having the best products and services in the industry. This reputation was earned over time because of the high levels of quality in product design. For over 100 years, Lennox has helped keep homes and businesses comfortable. This stability ensures they will stand behind their products. Lennox products have always led the way in design and performance innovation. When you see the Lennox label, you know you’re getting the finest, most innovative heating, cooling and indoor air quality products available that will provide exceptional performance and reliability.
Why should I choose an ENERGY STAR product for my home?
ENERGY STAR is a U.S. government-sponsored program that helps businesses and homeowners save energy and protect the environment by giving them the information they need to make smart choices about efficiency. One of the strongest reasons for choosing an ENERGY-STAR labeled product over a conventional model is that it can deliver significant savings. ENERGY STAR equipment can reduce your heating costs by as much as 40% and cooling costs up to 50%. By creating a more efficient home environment, you are contributing to a cleaner global environment. According to the EPA, if just one in ten households installed ENERGY STAR heating and cooling products, the change would keep more than 17 billion pounds of pollution out of the air.
What are the 90%+ AFUE Gas Furnaces?
(The G71P, G61V, G61, G51, G43 models)
These furnaces have an AFUE (Annual Fuel Utilization Efficiency) rating greater than 90%. That means that you will receive more than 90 cents of heat for every dollar that you spend on gas. They are all condensing furnaces which means there is water in the flue gases. In all cases the flue gases must be exhausted through a white plastic (PVC) pipe, typically to the side or rear of the house. This type of furnace should show average savings of 25% to 40% depending on the type of furnace you are replacing. A homeowner with a large old house, high gas bills, or one who plans on being in the home at least 10 years is a good candidate for one of the 90%+ furnaces. With lifetime warranties on the heat exchanger (with the exception of the G43 which has a 20 year warranty), they are units that will provide years of dependable satisfaction.
What are the 80%+ AFUE Gas Furnaces?
(The G60V, G60, G50, G40 models)
The AFUE on these furnaces is 80%. The flue gases exhaust at a higher temperature than the 90% furnace, therefore it can be vented through most chimneys. However, in many houses a metal flexible liner must be pulled through your existing chimney. This protects against the flue gases cooling and condensing in the chimney. The water would then seep back into the home and do damage to the plaster. A homeowner with a small house and small gas bills, or someone who is not going to live in the home for more than 5 years would likely choose this model. These models carry a 20 year limited warranty on the heat exchanger and will provide average savings of 15% to 25% depending on the type and age of furnace you are replacing.
Why is ventilation important for proper indoor air quality?
We were once able to achieve natural ventilation in our homes by merely opening a window. However, with the concern for energy efficiency, we have been busy making homes “tighter” from an energy standpoint. With HRV’s (heat recovery ventilators) and ERV’s (energy recovery ventilators), air can be circulated throughout your home using your existing forced air system. Bringing fresh air into your home could help reduce concentrations of indoor contaminants. With these innovative products, you can get fresh air and still maintain energy efficiency in your home.