The 2nd-century Chinese mechanical engineer and inventor Ding Huan of the Han Dynasty invented a rotary fan for air conditioning, with seven wheels 3 m (10 ft) in diameter and manually powered by prisoners of the time.[6] In 747, Emperor Xuanzong (r. 712–762) of the Tang Dynasty (618–907) had the Cool Hall (Liang Dian 涼殿) built in the imperial palace, which the Tang Yulin describes as having water-powered fan wheels for air conditioning as well as rising jet streams of water from fountains. During the subsequent Song Dynasty (960–1279), written sources mentioned the air conditioning rotary fan as even more widely used.[7]
A specialized air conditioner that is used only for dehumidifying is called a dehumidifier. It also uses a refrigeration cycle, but differs from a standard air conditioner in that both the evaporator and the condenser are placed in the same air path. A standard air conditioner transfers heat energy out of the room because its condenser coil releases heat outside. However, since all components of the dehumidifier are in the same room, no heat energy is removed. Instead, the electric power consumed by the dehumidifier remains in the room as heat, so the room is actually heated, just as by an electric heater that draws the same amount of power.
For a scheduled or emergency HVAC repair, you can count on SMO Energy and our team of certified technicians. We’re ready 24 hours a day and seven days a week to fix your heating system and deliver the professional and courteous service you expect from our family-owned and operated business. Aside from your system shutting down, several other signs that your HVAC system needs repairs include:
Absorption heat pumps are a kind of air-source heat pump, but they do not depend on electricity to power them. Instead, gas, solar power, or heated water is used as a main power source. An absorption pump dissolves ammonia gas in water, which gives off heat. Next, the water and ammonia mixture is depressurized to induce boiling, and the ammonia is boiled off, which absorbs heat from the outdoor air.[citation needed]

We maintain a complaint-free A+ rating with the Better Business Bureau, and are a 2017 Better Business Award Winner for ethics. Comfort Plus Services has achieved recognition as a Carrier Factory Authorized Dealer for sound business practices, technical expertise, and customer approval ratings. We simplify the demands of local weather and a comfortable home with upfront pricing, honest estimates, comprehensive service plans, and Emergency Service throughout Salisbury, Fruitland, Delmar, Hebron, Eden, Delmar, Parsonsburg, Pittsville, Mardela Springs, Princess Anne & Willards, MD and more. See our Areas of Service. For new home comfort systems, Comfort Plus Services protects your interests with a 100% money back guarantee. We provide expert service you can trust.
Feel perfectly comfortable at home with our innovative Lennox Residential heating, cooling and air quality systems. Lennox manufactures high-efficiency HVAC systems including furnaces and air conditioners designed to conserve energy and save money. Our complementing air filtration systems, humidifiers and dehumidifiers help keep indoor air quality healthy and clean.
For more than sixty years, Nerthling's Heating and Air Conditioning has continued a tradition of superior customer service across Erie County, including Erie, Millcreek and Fairview.  Family owned and operated, we treat you, your home, and your comfort the way we would like to be treated.  This commitment to integrity extends to every service and product we provide.  Our goal is to deliver the highest rewards for your investment, whether you require installation, maintenance, or repair.  We offer a wide range of styles and sizes of equipment, services, and resources to help you achieve your goals for temperature control, air quality, and energy savings.
Air conditioners come in two basic types—central and window. A central AC provides cooling to your entire home, while a window AC cools just the room where it’s installed. If you’re not using a heat pump, you can pair an air conditioner with a furnace to provide both heating and cooling. Just to make things a bit more confusing, a central air conditioner housed together with a furnace in a single cabinet is also known as a packaged unit!
Natural ventilation is a key factor in reducing the spread of airborne illnesses such as tuberculosis, the common cold, influenza and meningitis. Opening doors, windows, and using ceiling fans are all ways to maximize natural ventilation and reduce the risk of airborne contagion. Natural ventilation requires little maintenance and is inexpensive.[19]
Need 24-hour emergency furnace repair? We can provide that too. With our same-day service and live phone and online chat service available 24/7, we make your comfort our greatest priority. Heating and air conditioning should help you live a comfortable life, so let us help you make your home the most comfortable it has ever been. It’s easy, just grab your furnace repair coupon, then simply give us a call at 301-747-3140, chat or schedule an appointment with us online.
Reinstall the access panel and disconnect block. Turn on the circuit breaker and furnace switch. Then set the thermostat to a lower temperature and wait for the AC to start (see “Be Patient at Startup,” below). The compressor should run and the condenser fan should spin. If the compressor starts but the fan doesn’t, the fan motor is most likely shot. Shut off the power and remove the screws around the condenser cover. Lift the cover and remove the fan blade and motor (photo 7). Reinstall the blade and secure the cover. Then repower the unit and see if the fan starts. If it doesn’t, you’ve given it your best shot—it’s time to call a pro.

Taking used gas out of a fridge system and filling it into packages. Avoids release into the environment – an action that is environmentally irresponsible and illegal in many countries. This process is usually performed by a refrigeration contractor. This occurs during maintenance or when removing a refrigerant permanently due to equipment decommissioning or retrofitting to a new gas.
Humidity is becoming more of a concern to building operators and owners. High indoor humidity leads to mold and mildew growth inside the building. The are several methods of controlling indoor humidity. The simplest (and most expensive) method is to connect a humidistat to an electric heater. When the humidity inside the building rises above the humidistat set point, the heater is turned on. The additional heat causes the air conditioning system to run longer and remove more moisture.

A split system is a combination of an indoor air handling unit and an outdoor condensing unit. The indoor air handling unit contains a supply air fan and an air-to-refrigerant heat exchanger (or cooling coil), and the expansion device. The outdoor condensing unit consists of a compressor and a condenser coil. Split-systems are typically found in residential or small commercial buildings. These systems have the highest energy efficiency rating (EER) of all the available AC systems. Manufacturers are required to take the EER rating a step further and provide a seasonal energy efficiency rating (SEER) for use by consumers. SEER ratings vary widely and range from 10 to 20. The higher the SEER rating, the more efficient the AC system operates. If heating is required, an alternate method of heating the interior of the building must be used, usually in the form of electric or gas heating.
Time for a class in HVAC technology! Just in case you missed the first lesson, HVAC is short for Heating, Ventilation and Air Conditioning. It’s a whole system with the sole purpose of making the indoor environment habitably comfortable. HVAC systems are currently available in four different types. These four types of HVAC systems all come in different sizes and specifications to suit your business or home.
Keep your home comfortable all year round with Keep your home comfortable all year round with this high quality and efficient 14 SEER central heating and cooling heat pump system. This system is ideal for new or replacement residential or commercial applications and consists of the outdoor condenser indoor air handler with evaporator coil heat strip and 30 ...  More + Product Details Close
The U.S. Environmental Protection Agency (EPA) requires this certification since appliances that use refrigerants can harm the ecosystem if they're not properly installed or maintained. While the EPA mandates this area of HVAC work, requiring a technician to get a license is up to the state to decide. With that said, not all states demand contractors to obtain one.
When your furnace filter becomes dirty, dusty and clogged, you can expect some negative effects on your furnace efficiency and your indoor air quality. The forced air is supposed to get blown through the filter and the filter is supposed to trap any particles so they don’t end up in your air ducts and throughout the house. When the filter has trapped too many particles and it is clogged up, the air keeps blowing, but some of those trapped particles will end up in the system and your living space. Another effect is that the furnace has to work harder to get the same amount of air through that dirty filter, so your heating bills may go up.
An air conditioner cools and dehumidifies the air as is passes over a cold coil surface. The indoor coil is an air-to-liquid heat exchanger with rows of tubes that pass the liquid through the coil. Finned surfaces connected to these tubes increase the overall surface area of the cold surface thereby increasing the heat transfer characteristics between the air passing over the coil and liquid passing through the coil. The type of liquid used depends on the system selected. Direct-expansion (DX) equipment uses refrigerant as the liquid medium. Chilled-water (CW) can also be used as a liquid medium. When the required temperature of a chilled water system is near the freezing point of water, freeze protection is added in the form of glycols or salts. Regardless of the liquid medium used, the liquid is delivered to the cooling coil at a cold temperature.

As a Carrier Factory Authorized Dealer, M and M, Heating & Cooling, Plumbing & Electrical is qualified to properly size and install the most technologically advanced and well-regarded heating, cooling, and air quality products on the market today. Our team is NATE-certified, factory trained, EPA certified, and regularly updated, ensuring the right solution to any challenge.


Clean air delivery rate is the amount of clean air an air cleaner provides to a room or space. When determining CADR, the amount of airflow in a space is taken into account. For example, an air cleaner with a flow rate of 100 cfm (cubic feet per minute) and an efficiency of 50% has a CADR of 50 cfm. Along with CADR, filtration performance is very important when it comes to the air in our indoor environment. Filter performance depends on the size of the particle or fiber, the filter packing density and depth and also the air flow rate.[28]
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.
Even if your air conditioning unit is still working, depending on the type of system in your home today, you could recoup your investment in a new system in as little as three years. However, that doesn't mean that your system needs to be replaced. Furnaces, air conditioners, and other heating and cooling systems have made tremendous gains in efficiency over the past five years, so if you have an older unit, it is worth taking a look at whether or not a repair is the best investment.
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