A contactor is a $25 mechanical relay that uses low-voltage power from the thermostat to switch 220-volt high-amperage current to the compressor and condenser fan. AC contactors can wear out and are at the top of the list of common air conditioning service failures. Even if your contactor is working, it pays to replace it every five years or so. Unscrew the old contactor before removing the wires. Then move the wires to the new unit (photo 6).

A mini-split system typically supplies air conditioned and heated air to a single or a few rooms of a building.[38] Multi-zone systems are a common application of ductless systems and allow up to 8 rooms (zones) to be conditioned from a single outdoor unit. Multi-zone systems typically offer a variety of indoor unit styles including wall-mounted, ceiling-mounted, ceiling recessed, and horizontal ducted. Mini-split systems typically produce 9,000 to 36,000 Btu (9,500–38,000 kJ) per hour of cooling. Multi-zone systems provide extended cooling and heating capacity up to 60,000 Btu's.


There are a number of claims in the HVAC industry that make HVAC technicians sound like they know what they are doing, but the North American Technician Excellence (NATE) certification program is the only closed book examination and certification program, administered by a third party, that tests real world working knowledge of HVAC systems. That's why all of our service technicians complete and continue NATE certification training throughout their career with SMO.

We’ve lived our entire lives, and continue to work in Southern Maryland and parts of Virginia, and are committed to the local community. Both the loyalty of our long-term customers and our A+ BBB rating are a testament to our dedication. Exceeding your expectations for service and performance, T. N. Bowes Heating & Air Conditioning, Inc. delivers the results you’re looking for.


As the first Carrier Factory Authorized Dealer in the area, Nerthling's Heating and Air Conditioning is recognized for exemplary business practices, customer loyalty, and industry knowledge.  Our service team continues factory training, staying updated with ever-evolving techniques and technology.  We remain current with product development, qualifying us to identify equipment that accurately suits your needs and allows for maximum efficiency.  We install proven reliable systems with a track record of durability, in a variety of configurations, guaranteeing an ideal match to your expectations.  We specialize in the installation, service, and repair of air conditioning, heat pumps, furnaces, boilers, geothermal options, generators, air quality solutions, and ductless HVAC.

Extensive training – Over the years, we have had to learn continually and update our skills to stay top-of-the-line. We continue to offer state-of-the-art products today with the service skills to match. We offer 800 hours of training classes to our technicians every year. They also have access to factory resource personnel and engineers for consultation.
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
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Nothing is worse than having your furnace fail on the coldest night of the year. When your furnace needs a repair, you shouldn’t have to worry about the company providing your furnace repair services. You won’t have to – not when you give John Betlem Heating & Cooling a call. No matter what kind of furnace you own, our talented team of technicians are able to easily identify any problem your furnace might be having.
Vredevoogd Heating & Cooling is Michigan’s top Heating & Air – Furnace Repair & Replacement – Air Conditioning Repair and installation service. With decades of experience and expertise, Vredevoogd Heating & Cooling remains committed to offering affordable 24/7 service. Our skilled heating and cooling specialists are certified and background checked. Our team is here when you need us to meet all your heating and cooling needs.
In 1992, a non-governmental organization, Greenpeace, was spurred by corporate executive policies and requested that a European lab find substitute refrigerants. This led to two alternatives, one a blend of propane (R290) and isobutane (R600a), and one of pure isobutane.[18][22] Industry resisted change in Europe until 1993, and in the U.S. until 2011, despite some supportive steps in 2004 and 2008 (see Refrigerant Development above).[27][67]
Headquartered in Portsmouth, Virginia, Air Conditioning Specialists was established in 1997 and is a fully licensed, insured and experienced heating and cooling company. We strive to provide our customers with the quickest, most efficient HVAC service and installation. Our workmanship, along with the highest quality of home and business products available, ensures the dependable performance of your HVAC system and your family’s comfort year after year. Our staff welcomes the opportunity to serve you, and looks forward to building a long-term relationship. Our success is dependent upon 100% customer satisfaction and the referrals we receive from our many satisfied customers.
For complex commercial heating and cooling systems, you need an expert. When you run into malfunctions, it’s not a DIY job to fix it. At Air Blue Heating and Cooling Inc., we know how important your HVAC systems are to running your commercial facility. Anytime you need repairs, maintenance, or installations, contact our team of licensed professionals. With our extensive industry background, we provide the highest quality service for your systems. We always adhere to strict standards for procedures, training, and customer service. As a Carrier Factory Authorized Dealer, we meet rigid standards for customer service and technical expertise, so you know you’re getting the very best. Give us a call any time of the day for efficient, accurate, and long-lasting commercial HVAC services in Elk Grove Village, Addison, Bedford Park, Bensenville, Elmhurst, Chicagoland and the surrounding suburbs.

Do you need expertise in HVAC? Roswell and Marietta residents who choose Moncrief Heating & Air Conditioning get the benefit of over 118 years of reputable experience in air conditioning and furnace repair, service and installation. Whether you have an emergency or need routine service, we are available 365 days a year. Call us today at 404-350-2300.
If you need help with your air conditioner or want to learn more about the types of air conditioners available for your home comfort needs, explore HVAC.com’s HVAC Contractor Directory. Through the directory, you’ll be connected with local cooling contractors who can answer your questions and help you determine the best system and best value for your home. Just enter your ZIP code to see local HVAC contractors near you!

Nytech Heating and Cooling has proudly served Castle Rock, and Douglas county customers for over 10 years. We are passionate about customer service and truly care about your family and your home. We don't believe in cutting corners to boost profits. We do what it takes to get the job done correctly. Douglas County is our Home and we genuinely care about our neighbors.

This is a great option for cooling your home or business without having to deal with the ductwork.  Other systems require ductwork so that the cool air can travel throughout the space.  A ductless mini split air condition doesn’t require ductwork because it has an air conditioner or a heat pump outside that connects to units in the home that handle the cooling being pushed into them from outside.  You can control the temperature of a whole home or just one room by controlling the air handlers in each specific area.  This allows for more control and a more efficient way to control the temperature and cost of operating the ductless mini split air conditioner.
An air conditioner's compressor contains a refrigerant. As it works, it sends this refrigerant through the system. As warm air blows across the coil that carries this refrigerant, the heat transfers to the refrigerant (cool always absorbs warm). A fan moves the cooled air through the ducting and out of vents that lead into the rooms of your house. The refrigerant returns to the compressor where the absorbed heat is moved outside. The refrigerant is then sent through the coil once again to continue the cycle.

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