General Information on Air Conditioning, Heating, Ventilation, and Refrigeration

Overview - You can find a little bit of everything here from the history of air conditioning to information on air cleaners, humidifiers, dehumidifiers, filters, central air conditioning and electric and gas heating and how they work, indoor air quality, recycling, mold, and a host of other things.

The History of Air Conditioning - There have been many attempts throughout history to avoid the ravages of heat and to keep cool in the hot winter months. Only in the last 100 years has man developed machinery that will allow for him to do more that just take advantage of his surroundings to keep cool. He can now artificially manufacture weather to help him to stay comfortable.

Air Cleaners - When people think of pollution most of them think of car emissions and petrochemical plants polluting our city or town. Few think that their home may be a source of pollution but the truth is that the air may be 5 to 100 times more polluted than the air outside their home. According to the House of Representatives and the Environmental Protection Agency or EPA indoor air pollution is the biggest health problem in America. Find out why you may need an air cleaner here.

Annual Fuel Utilization Efficiency or AFUE - Gas and oil heaters and boilers are rated in AFUE or Annual Fuel Utilization Efficiency. AFUE calculates the percentage of heat delivered to your house and compares it to the amount of fuel that you supply to the furnace. For example a furnace that has a 80% AFUE rating converts 80% of the fuel that you supply to heat and the other 20% is not converted to heat and effectively lost out the flue or chimney. AFUE is limited in that it only refers to the unit's fuel usage and not its electrical consumption.

Black Mold and Other Toxic Mold - Mold is a type of fungi which is fluffy and can be white, yellow, pink, brown, green, gray, or black. Molds produce invisible spores which act like seeds and travel easily through the air. Under severe conditions thousands of mold spores can be carried in each cubic foot of air.

Carbon Monoxide - Carbon Monoxide is a colorless odorless and tasteless gas or liquid which is a byproduct of burning kerosene, gas, oil, charcoal, wood, tobacco, gasoline and other petroleum products and comes from incomplete oxidation of the carbon during the combustion process. Even at low levels it can cause fatigue, impaired brain function, upset stomach, dizziness, muscle pains, impaired vision, chest pain and shortness of breath.

Carbon Monoxide Detectors - The best way to keep your home safe from dangerous levels of Carbon monoxide or CO is to have a carbon monoxide detector or alarm. The United States CPSC or Consumer Product Safety Commission recommends that every home should have a carbon monoxide alarm or detector even if you don't have any fuel burning appliances.

Carbon Monoxide Poisoning - The safety level for carbon monoxide as specified by the Health and Safety Executive is 50 parts per million (ppm). Between 50 - 200 ppm a healthy adult who is exposed will experience a slight headache within 2-3 hours. Between 200 - 400 ppm a frontal headache occurs within 1-2 hours, becoming widespread in 3 hours. Between 400 - 800 ppm dizziness, nausea, and convulsions occur within 45 minutes, and unconsciousness occurs in 2 hours.

Central Air Conditioning - Almost all of us have experienced air conditioning but few of understand how it works. Most homes have central air conditioners which are often referred to as split systems. This means that there is a separate outdoor and indoor unit with copper tubing which connects the two transferring the refrigerant. An air conditioner is designed to take heat out of your home.

Central Heating - Electric heating or resistance heating converts electricity directly to heat. Electric heat is often more expensive than heat produced by combustion appliances like natural gas, propane, and oil. Electric resistance heat can be provided by baseboard heaters, space heaters, radiant heaters, furnaces, wall heaters, or thermal storage systems.

Centrifugal Chillers - In large buildings and multi story buildings a traditional air conditioner is not very effective because copper tubing must carry not only Refrigerant but oil or lubricant back to the compressor. The long distances between outdoor units are too long to allow for proper return of the oil and running ductwork for such long distances is similarly difficult so most contractors turn to chilled water.

Compressors Air Conditioning - An air conditioning compressor is a mechanical motor which pumps and compresses the Refrigerant gas into the high pressure side of the cooling cycle and causes the refrigerant to circulate through the system. It is the most expensive and important component in a system and without it there is no cooling. It is usually found inside the condensing unit although on some large commercial applications is may be an isolated component.

Condenser Air Conditioning - The outside or condensing unit in a residential system is commonly referred to an a condenser because it is the part of your system which condenses the refrigerant or Refrigerant.

Cooling Towers - Cooling towers come in all shapes and sizes. Unlike most air conditioning systems where air is used to dissipate the heat from the outside condenser coil a cooling tower uses water to cool the system down. In a large system where higher efficiency is needed using a cooling tower can be an excellent choice especially in areas with low humidity. The cooling tower creates a stream of low temperature water which trickles through a thick sheet of open plastic mesh.

Dehumidifiers - A dehumidifier is a small and simple air conditioner that draws the air over the cold coil or evaporator to condense the moisture and then the dry air passes through the hot coil or condenser to heat it back up to its original temperature.

Duct Cleaning Information - According to the House of Representatives and the Environmental Protection Agency or EPA indoor air pollution is the biggest health problem in America. Many companies are offering services, some legitimate and some not that are designed to capitalize on this awareness. Companies offering to clean the air ducts in your home have become very common.

Dust Mites - Anton Van Leeuwenhoek invented the microscope and shortly after in 1694 reported that a strange species of small insects live in house dust. We now know that dust mites are not insects but are closely related to spiders and ticks. Dust mites are invisible to the naked eye. They live in warm, humid areas like beds, carpet, couches, pillows, old clothing, etc. and feed on the dead skin or dander that falls off the bodies of humans and animals. In people who are sensitive to them their waste and shed skin is a major cause of allergies, second only to pollen.

Electric Heaters - Electric heating or resistance heating converts electricity directly to heat. Electric heat is often more expensive than heat produced by combustion appliances like natural gas, propane, and oil. Electric resistance heat can be provided by baseboard heaters, space heaters, radiant heaters, furnaces, wall heaters, or thermal storage systems.

Evaporators or Evaporator Coils - An evaporator or evaporator coil is a part or an air conditioning system and is sometimes referred to as a cooling coil or indoor coil. Liquid refrigerant or Refrigerant travels through a sealed copper tube and into the evaporator coil and then goes through a very tiny hole or metering device causing the liquid's pressure to drop significantly. This causes the refrigerant to expand which turns it into a low temperature, low pressure gas.

Fan Coils - A fan coil is an indoor component of a air conditioning or heat pump system. It is in effect an electric furnace or heater with an evaporator coil, a resistance heater, a blower, and a drain pan built inside. The electric heater provides heat on cold days and the evaporator supplies air conditioning on hot days.

Filters for Air Conditioners and Heaters - Heating and cooling systems can use many different types of filters. The main purpose of an air filters is to keep your indoor air conditioning system particularly the evaporator coil clean. Some filters are also capable of cleaning the contaminants in the air creating better indoor air quality and greatly improving health.

Refrigerant and Refrigerant leaks - The cooling medium of a air conditioning or refrigeration system is called its refrigerant. In most residential air conditioners and many refrigeration systems it is R-22 or Refrigerant which is a chlorofluorocarbon or CFC. Refrigerant is an Environmental Protection Agency controlled substance which is deemed hazardous if released into the environment and will damage the Earths ozone layer if not properly contained.

Gas Furnaces - Gas fired heaters or furnaces provide warm, consistent heat for your home or business by creating and circulating warm air through the duct work of your house and transferred to your house or business.

Gas and Oil Boilers - Gas and oil fired boilers provide warm, consistent radiant heat for your home or business by creating and circulating steam or hot water through insulated pipes and into baseboard or radiator type system. From there the heat is then transferred to the house or business when the air in your home moves across the outside of the radiators and absorbs the heat from the heated metal surface. The warm air is then circulated through your home by convection.

Heat Pumps - Heat pumps are a lot like air conditioners but give out both heating and cooling. Heat pumps and air conditioners both work on the same basic principles but heat pumps have a few extra controls like a reversing valve which effectively reverses the flow taking the heat from outside and transferring it inside for use in the colder winter months.

Heating Seasonal Performance Factor or HSPF - Heat pumps efficiency is rated in HSPF or Heating Seasonal Performance Factor. As a general matter the higher the rating the more heating and cooling you get per watt of electricity so the higher the number the better.

Humidifiers - Our bodies register heat as a combination of temperature and humidity. If you add humidity to dry, heated air in the winter you can set your thermostat to a lower temperature and still be just as comfortable while saving money on your natural gas bill. Humidifiers also prevent dry skin, help ease some repertory problems and sore throats, reduce winter colds, keep woodwork and other items from deteriorating, and reduce static electricity.

HVAC - HVAC is an abbreviation for heating, ventilation and air conditioning.

Hydronic and Steam Systems - Hydronic systems are HVAC systems that use a pump to circulate a heated or cooled medium like treated water and then use a pump to circulate the water to the building through plastic pipes installed into the concrete slab or other spaces. The medium then conducts the warmth or cooling to the surface of the floor or other areas where it radiates energy outward heating or cooling the room. This sends the medium right to the areas where it is needed significantly increasing the systems efficiency. Hydronic systems are closed loop meaning the same medium is reused over and over.

Indoor Air Quality (IAQ) - When people think of pollution most of them think of car emissions and petrochemical plants polluting our city or town. Few think that their home may be a source of pollution but the truth is that the air may be 5 to 100 times more polluted than the air outside their home.

Introduction to HVAC Design - The purpose of a Building's HVAC design is both high indoor air quality and energy efficiency. These dual considerations require an integrated design approach. A building's heating, ventilation, and air conditioning system (HVAC) creates a climate that allows for maximum comfort by compensating for changing climatic conditions. carbon monoxide gas heating

Motors for Blowers and Condenser Fans - Blower motors are the motors that blow air across the evaporator coil of an air conditioning system and deliver cooling to the interior of a home or building. Condenser motors are the motors in an condensing unit that pull air across the condenser coil and cool the superheated gas drawing the heat from the interior of a house. These motors vary in frame size, horsepower, rpm, voltage, number of speeds, manufacturer, and shaft size.

Natural Gas for Heating - Natural gas is a safe, environmentally friendly, and inexpensive fuel available for use in appliances and equipment in your home, business and for industrial applications. The National Fire Protection Association or NFPA reports that gas heat is responsible for fewer home fires than electric or oil fueled systems.

Odor absorbing Filters or Gas Phase Adsorption - Gas phase adsorption is the process of using an adsorption media to adsorb gases and odors in an air stream. Carbon is the most common and is used primarily for odor absorption. Adsorptive medias do not filter out any particles they are only designed to remove or reduce the levels of gases and odors and as such must be used in conjunction with some other form of air filtration system or air filter to keep the carbon or other media from collecting dust.

Recycling Refrigerants - The cooling medium of a air conditioning or refrigeration system is called its refrigerant. CFC's or chlorofluorocarbons are used as refrigerants in some commercial air conditioning and refrigeration systems. CFC's are considered to be 100% ozone depleting and are very dangerous to the environment.

Refrigerants - Refrigerant and Other Alternatives - The cooling medium of a air conditioning or refrigeration system is called its refrigerant. CFC's or chlorofluorocarbons are used as refrigerants in some commercial air conditioning and refrigeration systems. CFC's are considered to be 100% ozone depleting and are very dangerous to the environment.

Room Air Conditioners or Window Units - Window units or larger versions called through the wall units are small systems which have a compressor, blower, evaporator, condenser, controls, and other components all in a single cabinet. For a small house, an extra room or an apartment a room air conditioner or window unit is a cheap and easy alternative to a central air conditioning system.

Seasonal Energy Efficiency Ratio SEER - On of the most important things to consider when purchasing a unit is the efficiency. The higher the efficiency of the unit the more it will cost you in the beginning but an investment in a higher efficiency system will return your investment many times over in cost savings over the course of the equipments life span. Air conditioner efficiency is rated in SEER or Seasonal Energy Efficiency Rating.

Sound rating number SRN - Sound Rating Numbers or SRN is a method of measuring and comparing sound levels of air conditioners. Sound is not relevant to the efficiency of a unit but it can affect your comfort level. If your unit has a low sound level, you will hardly notice it is operating while high levels may mean many sleepless nights and annoyed neighbors.

Space Heaters - Space heaters are small sometimes portable heaters powered by oil, electricity, kerosene, and natural gas. Most space heaters are powered by a standard 120V three wire power cord. These heaters sometimes have fans to circulate the warm air and built in thermostats to allow the user to adjust them. They all must have adequate clearance for safety.

Static Pressure - Static pressure and pressure drop is the most important and overlooked variable in air conditioning ductwork design or any device that moves air for that matter. Improper understanding of static pressure when designing a air conditioning or heating system is a recipe for disaster.

Technicians servicing heating air conditioning equipment - Heating air conditioning and refrigeration installers and technicians install maintain and repair systems which control the temperature, humidity, air flow, and air quality in residential, commercial, industrial, and other buildings. Because heating, ventilation, air conditioning, and refrigeration systems are sometimes called HVACR systems, workers may be called HVACR technicians and installers.

Thermidistat Controls - Typical thermostats maintain the proper desired temperatures in homes and businesses by signaling to your HVAC equipment when appropriate temperature settings are reached but they do nothing to control humidity. Typically this was done by a humidistat which was separate and usually installed in an inaccessible area like inside a return air duct. Carrier's Thermidistat (TM) Control not only helps your heating and cooling equipment maintain the proper temperature but also monitors and controls humidity.HVAC information

Thermostats - Thermostats maintain the proper desired temperatures in homes and businesses by signaling to your HVAC equipment when appropriate temperature settings are reached. There are several types of thermostats available and they can vary from the simple to the complex.

Two Speed Central Air Conditioning - Two speed units are very much like traditional air conditioners but they can run on low speed up to 80% of the time, which uses less electricity than a conventional unit. When temperatures rise Two speed units shift into high speed to maintain the set point of the thermostat.

Ultraviolet Filters - Ultraviolet light is a frequency of energy generated by the sun. Since UV is invisible it is not really light but the term ultraviolet light has become the standard term for UV energy. Most light sources generate a small amount of UV but in order to purify air UV must be generated by electric lamps similar to ordinary fluorescent lights.

VAV System Design - The Advanced VAV System Design provides recommendations to help engineers improve the efficiency of large HVAC systems. It focuses on built-up variable-air-volume (VAV) systems in multistory office buildings.

Ventilators - Ventilators work by drawing fresh air into a filter and transferring the fresh air into the air conditioning system which is distributed through the home. These ventilators are often controlled by a wall mounted unit.

Willis Carrier the "father" of the modern air conditioning - Willis Havilland Carrier, known to many as "The Father of the modern Air Conditioner" was born on November 26, 1875 on his families farm in a small town in Angola, New York.

Zoning or Zoned HVAC Systems - Zoned cooling is the process of dividing a home or building into two or more separate zones which gives more control over the cooling and heating system allowing for individual control of temperature in each of these zones. There are several ways of doing this depending on the size of the home or building.