HVAC professionals in the US can receive training through formal training institutions, where most earn associate degrees. Training for HVAC technicians includes classroom lectures and hands-on tasks, and can be followed by an apprenticeship wherein the recent graduate works alongside a professional HVAC technician for a temporary period.[34] HVAC techs who have been trained can also be certified in areas such as air conditioning, heat pumps, gas heating, and commercial refrigeration.[35]
We want to compliment your fine sales and installation team. They are outstanding. Carlos, your sales rep., was highly informative. We reviewed our needs and we ultimately chose the Trane XV-18 variable speed system. Carlos did not try to up sell us with things that we did not need but he did help us choose the correct upgraded filter and UV light that we wanted. We told Carlos that our research indicated that the quality of the installation of the unit was at least as important as the unit itself, and Carlos agreed. Carlos pointed out that new proper sized duct work and copper wiring would be required for a correct installation, and that we needed to add two more returns. We asked if more returns were needed and Carlos said that would not be cost effective. That was great to hear. Carlos assured us that the installation team of Willie and Gary, both lead installers, would be used. They were both superb. They came on time and worked for 12 and 1/2 hours. It was a 93 degree day so the heat in the attic was intense. We kept telling them to take a break but they continued to work up there in what must have been 130+ temperatures. They were amazing! They were neat and cleaned up any mess they made. They patiently answered all of our many questions and gave us helpful tips. They were truly professional in all respects. We also note that Stacy, Angie and Karen of your office staff were each courteous, accommodating and efficient. They helped things to go smoothly. Carlos, Gary, Stacy, Angie, Willie and Karen are each great assets to your company. We would be comfortable recommending that team of people to anyone! Ken and Kathy Luban
At Gainesville Mechanical, Inc., we’ve been in the business of providing the most reliable 24-hour AC repair service throughout Gainesville, Lawrenceville, Buford, Dahlonega, Braselton & Cumming, GA, since 1977. Because of our years of unending quality AC unit repair service, we know exactly what our customers expect, and what they deserve. We’ve made it incumbent upon our technicians to always provide prompt, thoughtful service while following the strictest ethical standards in the industry. It’s our commitment to providing excellent residential and commercial AC repair that allows us to back up our work with a 100% Satisfaction Guarantee. Whether you require our services as a Bryant Factory Authorized Dealer, or as the providers of the finest 24-hour air-conditioning repair services in the country, you can relax in knowing that we’ll never deliver anything less than the very best AC unit repair at an AC repair cost that is always reasonable and fair.
All consumer and property manager beware of this is not the old frymire anymore. they are under new ownership and with bunch rip-off tech! I am the property manager with a handyman and were unable to get the heat pump furnace relay replaced on time so I gave them another chance to do it base on good experience in previous. however, the tech used old school trick:telling me his truck dont have the relay and need to get the parts then will call me back. lone story short, we end up been charged for 290 for just a relay! and he even quoted us for a bad run capacitor for total 460!! we called them to provide a detail work invoice as usual and they never send to us so we end up to tell landlord that's how it is.. Huge mistake I ever made..don't trust them at all!!
The performance of vapor compression refrigeration cycles[27] is limited by thermodynamics. These air conditioning and heat pump devices move heat rather than convert it from one form to another, so thermal efficiencies do not appropriately describe the performance of these devices. The Coefficient-of-Performance (COP) measures performance, but this dimensionless measure has not been adopted. Instead, the Energy Efficiency Ratio (EER) has traditionally been used to characterize the performance of many HVAC systems. EER is the Energy Efficiency Ratio based on a 35 °C (95 °F) outdoor temperature. To more accurately describe the performance of air conditioning equipment over a typical cooling season a modified version of the EER, the Seasonal Energy Efficiency Ratio (SEER), or in Europe the ESEER, is used. SEER ratings are based on seasonal temperature averages instead of a constant 35 °C (95 °F) outdoor temperature. The current industry minimum SEER rating is 14 SEER.[28]
From winter's chill through the dog days of summer, our primary goal at Bailey's Comfort Services is to keep your home comfortable for you and your family. But, that's just the beginning. We also offer you peace of mind, ensuring your equipment operates safely. We help you save money on your fuel bills. And, we help deliver relief to those with allergies and those concerned with the quality of the air they breathe.
Air Conditioning Your home's air conditioner is an essential part of your overall indoor comfort. A properly working system can mean the difference between a cool, comfortable summer and a hot, miserable few months. If you're currently dealing with a broken air conditioner, an inefficient system, or you would like to schedule a routine, pre-season tune-up, Horizon Services is here to help!
The use of furnaces, space heaters, and boilers as a method of indoor heating could result in incomplete combustion and the emission of carbon monoxide, nitrogen oxides, formaldehyde, volatile organic compounds, and other combustion byproducts. Incomplete combustion occurs when there is insufficient oxygen; the inputs are fuels containing various contaminants and the outputs are harmful byproducts, most dangerously carbon monoxide, which is a tasteless and odorless gas with serious adverse health effects.[14]

A multi-split system[44] is a conventional split system, which is divided into two parts (evaporator and condenser) and allows cooling or heating of several rooms with one external unit. In the outdoor unit of this air conditioner there is a more powerful compressor, ports for connecting several traces and automation with locking valves for regulating the volume of refrigerant supplied to the indoor units located in the room.
In addition to the information below, see these two articles for the general care and maintenance of your air conditioner: Preparing Your Air Conditioner for Summer and How to Replace Furnace & AC Filters. Most noteworthy, you should replace the filters at least twice a year, before the heating and cooling seasons. For information on furnace problems, please see Furnace Not Working.
Dehumidification (air drying) in an air conditioning system is provided by the evaporator. Since the evaporator operates at a temperature below the dew point, moisture in the air condenses on the evaporator coil tubes. This moisture is collected at the bottom of the evaporator in a pan and removed by piping to a central drain or onto the ground outside.

The last thing you need is for your air conditioning to stop working in the middle of a heat wave. If this has ever happened to you, you understand the need for a reliable company to come out and get the air conditioning going again. Let us prove to you that we are the right company for you in Southern Maryland. As a service we do offer maintenance of all air conditioning units to help prevent this problem, but we understand that things happen!
To keep your furnace in good working order it’s important to have it regularly cleaned. The national average furnace cleaning cost ranges from $60 to $80, though prices can vary greatly based on where you live in the country and what your furnace maintenance includes. An HVAC company may have different rates for different levels of furnace maintenance. For example,one company may offer general furnace maintenance for $79 and advanced maintenance for $138. Another company may offer a 38-point maintenance check for $89 and a 64-point maintenance check for $178. According to Energy.gov, a standard furnace cleaning and maintenance visit can include:
When you establish routine visits with Vredevoogd Heating & Cooling Grand Rapids MI, you can enhance the longevity of your HVAC system with our custom care. Our technicians are skilled at performing comprehensive inspections. We routinely spot small issues before they can turn into major repairs. By optimally maintaining your system, we can extend its life and ensure that it reliably meets your household’s heating and cooling needs. You can also join our Comfort Club! You can schedule routine appointments to service your system before the hot and cold seasons. If you discover a problem afterward, call us to provide you with immediate service. We can troubleshoot the problem in no time. We’ll give you an upfront estimate concerning cost, parts, and labor. There’s no guessing when it comes to our service and costs. Our techs will provide you with everything you need to know about their service from beginning to end of the job. We even have Financing Available.
Whole-house fans have helped cool homes for a century. The basic design is simple: An attic-mounted fan pushes hot air out through attic vents and draws cooler, outside air in through open doors and windows. This rapid air exchange—large fans can purge a house of hot air in two to three minutes—not only removes built-up heat but also creates a pleasant breeze.
If your compressor doesn’t have an overload button and you hear it humming or buzzing, poke a screwdriver or stick down through the top grille and try to spin the fan blades clockwise. If doing this gives the fan enough of a boost to get it going, the unit has a faulty capacitor that must be replaced. See How to Test and Replace an AC Run Capacitor, above.
Nobody wants to deal with a broken furnace in winter. Lucky for you, our Denver furnace repair specialists are available 7 days a week. Don’t face cold winter nights without a well functioning furnace. Contact us, your Denver furnace repair company so that we can diagnose the problem and set you up with a preventative maintenance package so we can catch problems before they occur. Click HERE to learn more about our furnace related services.
When natural gas, propane or heating oil are burned in a furnace, the resulting hot combustion gasses by burning natural gas, propane or heating oil circulate through a heat exchanger. The heat exchanger will, in turn, release that heat to be circulated by the furnace’s blower. The flue gas then travels through the flue vent, which carries the gas outside of the home. When a heat exchanger is cracked, it generally will require a complete system replacement. That is one of the reasons why we highly recommend annual preventive maintenance on your home’s furnace – this preventative furnace inspection and maintenance can greatly prolong the life of your home heating system.
When natural gas, propane or heating oil are burned in a furnace, the resulting hot combustion gasses by burning natural gas, propane or heating oil circulate through a heat exchanger. The heat exchanger will, in turn, release that heat to be circulated by the furnace’s blower. The flue gas then travels through the flue vent, which carries the gas outside of the home. When a heat exchanger is cracked, it generally will require a complete system replacement. That is one of the reasons why we highly recommend annual preventive maintenance on your home’s furnace – this preventative furnace inspection and maintenance can greatly prolong the life of your home heating system.
Air conditioners often use a fan to distribute the conditioned air to an occupied space such as a building or a car to improve thermal comfort and indoor air quality. Electric refrigerant-based AC units range from small units that can cool a small bedroom, which can be carried by a single adult, to massive units installed on the roof of office towers that can cool an entire building. The cooling is typically achieved through a refrigeration cycle, but sometimes evaporation or free cooling is used. Air conditioning systems can also be made based on desiccants (chemicals which remove moisture from the air) and subterraneous pipes that can distribute the heated refrigerant to the ground for cooling.[2]

The belt should slip right into place. If it seems to be too tight or difficult to set in place, it may be necessary to adjust the motor mount to provide more slack. Then you can re-tighten the tension once the belt is in place. Check the manufacturer’s specifications for proper tension—in most cases, the belt should deflect about an inch when you press down on it.

"Warren at Lighten Up came in on time and as scheduled. Loved working with him. He provided new lighting for our kitchen remodel and did a great job. He still needs to come back and hook everything up. Also Seth came in and did some plumbing work and repair that we did not even know needed repair. I highly recommend this company and look forward to working with them in the future"


Finally, don't underestimate the thermostat as a potential reason why your furnace is not working. Everything on the heating unit itself may function perfectly, but your home still will not heat right if the console you use to set the temperature doesn't communicate your input. A faulty thermostat can either be due to the wall unit itself, or the wiring that connects it to your furnace. Average thermostat repair costs are between $108 and $282, including labor. Replacement costs, of course, depend on the thermostat you choose. Visit our thermostat repair cost guide to learn more about this type of issue.


Any forced air system in your home - whether it is powered through electric or gas-generated energy - requires a blower motor. This component consists of an electric motor and fan, and is responsible for pushing air evenly through the furnace. As hvac.com points out, you can easily identify the blower motor in your furnace as the part that looks similar to a hamster wheel at the bottom of the unit. If it stops working, the air needed to heat your home will no longer be pushed through the furnace to be heated and distributed evenly. In that case, you need to inquire about potential repairs. Blower motor repair typically costs between $150 for a simple fix, and $450 for complete replacement and installation of the part. Where you land on that range depends on the exact damage.
The professionals here at Brothers Plumbing, Heating and Electric are well trained, experienced and seasoned experts. We have been the go-to plumbing, electrical and HVAC company in the area for over 35 years and we always come highly recommended by our many satisfied customers. We offer a 100% satisfaction guarantee, have an A+ Rating with the BBB, won the Thornton “People’s Choice Award” for 2016, drug test and background check all of our employees, email you a picture of the technician who will be providing the service before arrival and call once the service is complete to ensure 100% satisfaction. So what are you waiting for? With our competitive pricing, trained and experienced technicians, and well-rounded list of home services, we’re clearly the company to trust. Get in touch with us here at Brothers Plumbing, Heating and Electric to schedule your needed service today!
Gainesville Mechanical Inc is open for regular business hours, Monday through Friday, from 8 a.m. to 5 p.m. We offer everyday extended business hours, at regular rates, to meet the challenge of your busy schedule with flexible appointment times, and always have a licensed technician at your door within 24 hours.  For desperate times, we protect your home, comfort, and safety with 24/7 Emergency Assistance without added after-hour costs.  Contact us at 770-532-9130, and rest assured, we prioritize your best interests.  Our skilled service never comes with inflated or hidden charges.  We provide affordable rates, upfront pricing, and the detailed information you need to make the best possible decisions.  We service all makes and models of cooling equipment, optimizing safety, efficiency, and reliability, to deliver superior, ongoing performance.  Trust our award-winning team of NATE-certified technicians to restore your comfort today, with repairs that ensure long-term satisfaction.
Before opening the electrical cover on the A/C unit, be sure to shut off all power to the compressor unit and the indoor furnace or air handler, and verify that it is off. Note that this may mean shutting off a circuit breaker that serves the furnace and air handler, and then, near the compressor, pulling out the disconnect block (or shutting off the 220-volt power) to the outdoor compressor.
Vredevoogd Heating & Cooling Grand Rapids MI routinely serves the areas of Grand Rapids, Wyoming, Lansing, Grandville, and Kalamazoo. We provide a comprehensive menu of HVAC services delivered by certified HVAC technicians who specialize in heating and cooling repair and installation. World-class customer service is a cornerstone of our business and we are committed to doing the job right the first time. We have a reputation for integrity and service excellence. By living up to our good name, we continue to build our customer base throughout the Michigan region and look forward to adding you to our service family. So if you are looking for a “heating & air company near me” in Grand Rapids, or a Furnace Repair Lansing, Furnace Repair Kalamazoo and more. Call today.

Vredevoogd Heating & Cooling Grand Rapids employs more than 80 people who are proud to work under the Vredevoogd Heating & Cooling banner. Each team member shares our company values for service excellence. All of our employees are intensely screened and background checked so that you have peace of mind when they enter your home. Moreover, our technicians are certified to work in the HVAC industry and provide the level of expertise that our customers expect from Vredevoogd Heating & Cooling. We back our technicians’ work and continue to make training a priority so that all of our techs are familiar with the latest HVAC models and advances. Our customers deserve the best, so the best is what we deliver to each and every job.

As a locally owned and operated HVAC contractor we are not owned by anyone else but ourselves. This allows us to keep our prices reasonable. It also allows us to keep our responses personal and our service reliable because we directly answer to each of our customers. If we send one of our technicians to service a call anywhere in Southern Maryland, we recognize that their customer service is a direct reflection on our business name – so we want your satisfaction to be 100%.
With the split system, the evaporator coil is connected to a remote condenser unit using refrigerant piping between an indoor and outdoor unit instead of ducting air directly from the outdoor unit. Indoor units with directional vents mount onto walls, suspended from ceilings, or fit into the ceiling. Other indoor units mount inside the ceiling cavity, so that short lengths of duct handle air from the indoor unit to vents or diffusers around the rooms.
In the event of an emergency with your residential heating and cooling system, we understand that you simply cannot wait! At R.S. Andrews, we take your comfort and well-being seriously and are proud to offer our emergency HVAC repair at any hour, on any day—including weekends! We provide only the highest quality services to ensure your needs are met!
Most Michigan HVAC repair companies will often charge a “Travel Charge” or “Diagnosis Fee.” Randazzo calls this fee simply, a “Service Call Fee.” This will be the minimum cost of the repair. It is not recommended to judge a company on how expensive or how cheap their service rates are. In most cases, with larger companies the rates will be higher. This is not because they may have more overhead but simply because of the quality and preparedness of the service that will be preformed.
Air changes per hour Bake-out Building envelope Convection Dilution Domestic energy consumption Enthalpy Fluid dynamics Gas compressor Heat pump and refrigeration cycle Heat transfer Humidity Infiltration Latent heat Noise control Outgassing Particulates Psychrometrics Sensible heat Stack effect Thermal comfort Thermal destratification Thermal mass Thermodynamics Vapour pressure of water
Architectural acoustics Architectural engineering Architectural technologist Building services engineering Building information modeling (BIM) Deep energy retrofit Duct leakage testing Environmental engineering Hydronic balancing Kitchen exhaust cleaning Mechanical engineering Mechanical, electrical, and plumbing Mold growth, assessment, and remediation Refrigerant reclamation Testing, adjusting, balancing

Though Harrison had commercial success establishing a second ice company back in Sydney in 1860, he later entered the debate over how to compete against the American advantage of ice-refrigerated beef sales to the United Kingdom. He wrote: "Fresh meat frozen and packed as if for a voyage, so that the refrigerating process may be continued for any required period", and in 1873 prepared the sailing ship Norfolk for an experimental beef shipment to the United Kingdom. His choice of a cold room system instead of installing a refrigeration system upon the ship itself proved disastrous when the ice was consumed faster than expected.[citation needed]
You might guess it from the name: the heat exchanger is the part of your furnace that actually heats the air your blower motor pushes through the furnace. It consists of a chamber in which the heat energy produced by natural or propane gas is transferred to the forced air. At the same time, this part also includes a vent through which the gases themselves are safely removed from the unit and the air that enters your home. Because of these gases, a problem with your heat exchanger needs to be dealt with promptly. Over time, cracks in the exchanger can result in carbon monoxide leaks. Taking care of the problem once again means understanding the existence of a range: repairing your heat exchanger can cost as little as $100, but a full replacement may cost up to $1,200.
Before opening the electrical cover on the A/C unit, be sure to shut off all power to the compressor unit and the indoor furnace or air handler, and verify that it is off. Note that this may mean shutting off a circuit breaker that serves the furnace and air handler, and then, near the compressor, pulling out the disconnect block (or shutting off the 220-volt power) to the outdoor compressor.
Heaters exist for various types of fuel, including solid fuels, liquids, and gases. Another type of heat source is electricity, normally heating ribbons composed of high resistance wire (see Nichrome). This principle is also used for baseboard heaters and portable heaters. Electrical heaters are often used as backup or supplemental heat for heat pump systems.
An example of a geothermal heat pump that uses a body of water as the heat sink, is the system used by the Trump International Hotel and Tower in Chicago, Illinois. This building is situated on the Chicago River, and uses cold river water by pumping it into a recirculating cooling system, where heat exchangers transfer heat from the building into the water, and then the now-warmed water is pumped back into the Chicago River.[25]
Finally, don't underestimate the thermostat as a potential reason why your furnace is not working. Everything on the heating unit itself may function perfectly, but your home still will not heat right if the console you use to set the temperature doesn't communicate your input. A faulty thermostat can either be due to the wall unit itself, or the wiring that connects it to your furnace. Average thermostat repair costs are between $108 and $282, including labor. Replacement costs, of course, depend on the thermostat you choose. Visit our thermostat repair cost guide to learn more about this type of issue.
In addition to the information below, see these two articles for the general care and maintenance of your air conditioner: Preparing Your Air Conditioner for Summer and How to Replace Furnace & AC Filters. Most noteworthy, you should replace the filters at least twice a year, before the heating and cooling seasons. For information on furnace problems, please see Furnace Not Working.

James Harrison's first mechanical ice-making machine began operation in 1851 on the banks of the Barwon River at Rocky Point in Geelong, Australia. His first commercial ice-making machine followed in 1853, and his patent for an ether vapor compression refrigeration system was granted in 1855. This novel system used a compressor to force the refrigeration gas to pass through a condenser, where it cooled down and liquefied. The liquefied gas then circulated through the refrigeration coils and vaporized again, cooling down the surrounding system. The machine produced 3,000 kilograms (6,600 lb) of ice per day.[citation needed]


In 1906, Stuart W. Cramer of Charlotte was exploring ways to add moisture to the air in his textile mill. Cramer coined the term "air conditioning", using it in a patent claim he filed that year as an analogue to "water conditioning", then a well-known process for making textiles easier to process. He combined moisture with ventilation to "condition" and change the air in the factories, controlling the humidity so necessary in textile plants. Willis Carrier adopted the term and incorporated it into the name of his company.[10]
5) Your air conditioner is short cycling. It is perfectly normal for your air conditioner to cycle on and off to maintain a set temperature throughout your home. However, if you notice that it is turning on and off more frequently than usual and the outside temperature is not particularly warmer than normal, it is possible that your unit is malfunctioning. Short cycling puts extra stress on your air conditioner, and can cause it to fail if not handled quickly. 
Central home air conditioner service systems consist of two major components: a condensing unit that sits outside your house, and the evaporator coil (often referred to as an A-coil) that sits in the plenum of your furnace or air handler. The refrigerant in the A-coil picks up the heat from your home and moves it to the outdoor condensing unit. The condensing unit fan blows outside air through the condensing coil to remove the heat. The condensing unit houses the three parts replaceable by a DIYer: the contactor, the start/run capacitor(s) and the condenser fan motor. The condensing unit also houses the compressor, but only a pro can replace that. The A-coil has no parts that can be serviced by a DIYer.
This information is not intended as an offer to sell, or the solicitation of an offer to buy, a franchise. It is for information purposes only. Read More Currently, the following states regulate the offer and sale of franchises: California, Hawaii, Illinois, Indiana, Maryland, Michigan, Minnesota, New York, North Dakota, Oregon, Rhode Island, South Dakota, Virginia, Washington, and Wisconsin. If you are a resident of or want to locate a franchise in one of these states, we will not offer you a franchise unless and until we have complied with applicable pre-sale registration and disclosure requirements in your state. Read Less Aire Serv is a registered trademark of Aire Serv LLC © Aire Serv | All rights reserved | All Aire Serv franchise locations are independently owned and operated.
Finally, don't underestimate the thermostat as a potential reason why your furnace is not working. Everything on the heating unit itself may function perfectly, but your home still will not heat right if the console you use to set the temperature doesn't communicate your input. A faulty thermostat can either be due to the wall unit itself, or the wiring that connects it to your furnace. Average thermostat repair costs are between $108 and $282, including labor. Replacement costs, of course, depend on the thermostat you choose. Visit our thermostat repair cost guide to learn more about this type of issue.
Visit our one-of-a-kind showroom and explore the latest options on the market today. Check out sound decibel levels, heating and cooling capacity, learn how these systems work and compare old to new. The team from Strongsville Heating & Air Conditioning provides the products, guidance and service you can trust to surpass all your expectations. The weather is no match for our dedication to your satisfaction. At Strongsville Heating & Air Conditioning Customers Set the Goal….We Exceed It!
The most recognized standards for HVAC design are based on ASHRAE data. The most general of four volumes of the ASHRAE Handbook is Fundamentals; it includes heating and cooling calculations. Each volume of the ASHRAE Handbook is updated every four years. The design professional must consult ASHRAE data for the standards of design and care as the typical building codes provide little to no information on HVAC design practices; codes such as the UMC and IMC do include much detail on installation requirements, however. Other useful reference materials include items from SMACNA, ACGIH, and technical trade journals.
In hot weather, air conditioning can prevent heat stroke, dehydration from excessive sweating and other problems related to hyperthermia. Heat waves are the most lethal type of weather phenomenon in developed countries. Air conditioning (including filtration, humidification, cooling and disinfection) can be used to provide a clean, safe, hypoallergenic atmosphere in hospital operating rooms and other environments where proper atmosphere is critical to patient safety and well-being. It is sometimes recommended for home use by people with allergies.
At Genz-Ryan, we are here for you 24 hours a day, 7 days a week so you can count on us for all your heating repair work in the Minneapolis area. Our furnace repair technicians are well-trained and experienced. They’re ready to take care of any heating issue that you may have. We are a Lennox Premier Furnace Dealer and provide expert furnace repair service for most of the Minneapolis/St. Paul area. For over 60 years we have been getting the job done right the first time.
In 1758, Benjamin Franklin and John Hadley, a chemistry professor at Cambridge University, conducted an experiment to explore the principle of evaporation as a means to rapidly cool an object. Franklin and Hadley confirmed that evaporation of highly volatile liquids (such as alcohol and ether) could be used to drive down the temperature of an object past the freezing point of water. They conducted their experiment with the bulb of a mercury thermometer as their object and with a bellows used to speed up the evaporation. They lowered the temperature of the thermometer bulb down to −14 °C (7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that, soon after they passed the freezing point of water 0 °C (32 °F), a thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about 6 mm (1⁄4 in) thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded: "From this experiment one may see the possibility of freezing a man to death on a warm summer's day."[9]
In 1758, Benjamin Franklin and John Hadley, a chemistry professor at Cambridge University, conducted an experiment to explore the principle of evaporation as a means to rapidly cool an object. Franklin and Hadley confirmed that evaporation of highly volatile liquids (such as alcohol and ether) could be used to drive down the temperature of an object past the freezing point of water. They conducted their experiment with the bulb of a mercury thermometer as their object and with a bellows used to speed up the evaporation. They lowered the temperature of the thermometer bulb down to −14 °C (7 °F) while the ambient temperature was 18 °C (64 °F). Franklin noted that, soon after they passed the freezing point of water 0 °C (32 °F), a thin film of ice formed on the surface of the thermometer's bulb and that the ice mass was about 6 mm (1⁄4 in) thick when they stopped the experiment upon reaching −14 °C (7 °F). Franklin concluded: "From this experiment one may see the possibility of freezing a man to death on a warm summer's day."[9]
In the most general sense, air conditioning can refer to any form of technology that modifies the condition of air (heating, (de-) humidification, cooling, cleaning, ventilation, or air movement). In common usage, though, "air conditioning" refers to systems which cool air. In construction, a complete system of heating, ventilation, and air conditioning is referred to as HVAC.[3] 
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