The Glossary below has been provided to define and explain common heating- and furnace-related terms and phrases. If you find anything on the site that isn't explained here, please feel free to contact us so that we can add it below.

AFUE
Annual Fuel Utilization Efficiency ratings are similar to the gas mileage ratings on a car. The higher the AFUE number, the higher the efficiency and the greater the energy savings.

Deluxe Furnace
Equipment selection is extremely important. There are many sub tier furnace manufacturers which means they do not have much in the way of market share simply because their products do not meet the needs of the informed consumer. The only way to be assured of a quality product is to select equipment from the top manufacturers. However, even the larger manufacturers do make lower cost entry level units that are typically installed in track homes where the main concern is the first year warranty period.

A deluxe furnace is manufactured to a higher standard and will typically include:

· An insulated blower compartment. This means quieter operation.
· 20 year + heat exchanger warranties
· 3 or more years warranty on the system microprocessor.
· 3 or more years warranty on the hot surface igniter.

If you are getting other bids always ask “Are you quoting me a deluxe unit”? The cost between a standard unit and deluxe unit is very small and not worth the discount when your total comfort system is concerned.

Deluxe Two-Stage Furnaces
A two stage furnace has the ability to operate in two stages based on what the actual demand for heat is in the home. This means that over 80% of the time the furnace will operate at 50% capacity since rarely is full capacity needed. When your furnace operates at the lower heat stage the fan speed is also reduced. This means that you will not only save energy dollars your furnace will be quieter and more efficient. When needed the furnace will operate at 100% capacity.

Deluxe Variable Speed Furnaces
A deluxe variable speed furnace has all of the features of a deluxe two stage furnace and includes:
· A variable speed blower motor to better match the actual system airflow requirements.
· Reduced system sound levels.
· Up to 80% less electrical energy required to operate the blower compared to non variable speed models.

Filtration
Your filtration system is an important part of your total comfort system. Selection of a proper filtration system can and will improve the indoor air quality in your home resulting in improved comfort and reduced allergy and asthma symptoms.

Do not be misled by large efficiency ratings when they quote the rating in “Arrestance”. This rating is related to its total dust holding ability. The more realistic rating is the “Atmospheric Dust Spot Efficiency Rating”. This is a much more rigid rating standard that tests the filters ability to actually capture atmospheric dust.

Standard Filters
The typical standard air filters that are used in a heating system are rated at less than 10% efficiency relating to dirt removal ability. Their primary function is to protect the heating equipment. They are not very effective in removing the small dust particles that cause allergy and asthma symptoms.

Electrostatic Air Filters
A good quality electrostatic air filter is guaranteed for life, washable and is made of electrostatic fibers to aid in dust collection. They also will be treated with an anti-microbial treatment to inhibit fungal and bacterial growth on the filter. Their efficiency can be from 10-22%.

Electronic Air Cleaners
Electronic air cleaners are considered very high efficiency air cleaners. They create an electrical charge on the dust particle and then use a collector plate with the opposite charge to collect the particle. These units have proven to be very effective over a wide range of particle sizes. Their efficiencies can range from 70-90% depending on the particle size. The collector cells are removed and cleaned on a regular basis. The initial cost of this filtration system is higher, however, their efficiency ratings are high and life cycle costs are much lower than any other medium to high efficiency filtration system on the market.

Sealing
This means no duct tape will be used to seal any portion of your new furnace installation. Studies have shown that duct tape does not stand up over time to the temperature changes experienced in a heating system. The duct tape breaks down and results in leakage of air from or into your heating system. The California Energy Commission has banned the use of duct tape in new home construction.

Standard Installation
A standard furnace installation includes:
· Removal and disposal of your old furnace
· Installation of new selected furnace and options.
· Sheetmetal adapter and proper sealing.
· Connect gas and electrical to new furnace.
· Connect flue
· New programmable thermostat
· Start up and testing of system
· One year parts and labor warranty. (Extended warranties available)

Startup and Testing of System
Connecting the gas and electrical to a new furnace and making sure it turns on does not constitute the proper startup and testing of a new furnace. Mechanical Air Service includes the following services in their start up and testing of a new furnace.
· Leak test all gas connections
· Test and inspect all safety controls.
· Setting the heat anticipator on your thermostat to match the new furnace if a programmable thermostat is not installed. This is extremely important to the proper operation of your furnace.
· Checking and recording the heat temperature rise across the new furnace. This is important to be sure the furnace operates in the temperature range it is designed for. New furnaces have multiple speed blowers that may need to be adjusted to provide the proper comfort levels in your home. Without this testing, proper design efficiencies may not be met.
· Testing and recording the total external static pressure of your heating system. This is another important measurement of your systems performance and can have a direct relationship to your furnace operating at its design efficiency and the comfort in your home. Unfortunately, many contractors have no idea how to conduct this measurement or what impact it has on the systems operation and its efficiency.

An improperly installed system will never perform at the efficiency level it was designed for. This means even though you purchased a high efficiency unit, if it is not installed correctly, tested and commissioned properly you have wasted your money.

System Evaluation
A quality conscious, experienced and professional contractor does not simply remove and replace a furnace. They conduct a system evaluation which takes into account the actual size of your home (many older heating systems are oversized) and any particular operational or system deficiencies you may have noticed such as:
· Your furnace seems to cycle on and off frequently.
· You feel cold drafts in your home.
· Supply air registers have dirt streaks. (This rarely has anything to do with your filters!)
· Do you have rooms that receive too much or too little heat?
· If you have a two story home with one furnace do you experience significant temperature differences between floors? This impacts the comfort in your home, is a waste of energy and can be corrected without adding a second furnace.
· Do you have unused rooms in your home that you close the registers in to save energy? Contrary to popular belief that does not save energy and can actually harm your furnace. Your furnace has no way of knowing a register is closed. It is designed to produce a specific amount of heat and will do that regardless of whether you have closed a register or not. Closing registers can reduce the overall airflow in your heating system resulting in higher than normal heat exchanger temperatures and reduced life expectancy of your furnace. The good news is this situation can be compensated for.
· Do any family members suffer from allergies or asthma? Your heating system can help reduce your symptoms by improving the filtration of the air in your home and reducing the amount of airborne dust particles and mold spores.

Ultra-Violet Light Systems
Ultra violet light (UV) systems generate an ultra violet light source in the “C” bandwidth and in the germicidal kill range. Doctors and hospitals have used UVC light to sterilize tools for many years.

As air flows across the UVC light source mold and fungal spores and bacteria are killed and or rendered unable to reproduce. These light systems have proven to be a very effective tool in improving the indoor air quality and environment in homes.

If your environmental system also has air conditioning a UVC light system provides some additional benefits. The light source helps keep the cooling coil clean improving its efficiency and reducing maintenance needs. It also helps reduce the possibility of microbial contamination on the cooling coil.

If someone in your home suffers from allergy or asthma symptoms a UVC light system can help them. Be sure to only purchase a high intensity UV light system.