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.[31]


The use of CFC as a refrigerant was once common, including the refrigerants R-11 and R-12 (sold under the brand name Freon-12). Freon refrigerants were commonly used during the 20th century in air conditioners due to their superior stability and safety properties. When they are released accidentally or deliberately, these chlorine-bearing refrigerants eventually reach the upper atmosphere.[61] Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine radicals catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst until it binds with another radical, forming a stable molecule and quenching the chain reaction.


Free cooling systems can have very high efficiencies, and are sometimes combined with seasonal thermal energy storage so that the cold of winter can be used for summer air conditioning. Common storage mediums are deep aquifers or a natural underground rock mass accessed via a cluster of small-diameter, heat-exchanger-equipped boreholes. Some systems with small storages are hybrids, using free cooling early in the cooling season, and later employing a heat pump to chill the circulation coming from the storage. The heat pump is added-in because the storage acts as a heat sink when the system is in cooling (as opposed to charging) mode, causing the temperature to gradually increase during the cooling season.

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
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.
I have a very old HVAC. The heater went out. I had just purchased the heater check package from Angie's list and it went out the nex tday. I called them and John came within a day or so. He found the problem after checking several items (fuse in heater shorting). He ordered the part and there was a delay due to getting the part and then the ice storm. As soon as the part was in John texted me. When I was available, John came back in a reasonable time and fixed it. He always called half hour before he was en route to notify me and was very punctual. He is professional and knowledgeable. He used my coupon toward my total bill and I have heat! I will use him again and am thankful he could get out and get it fixed at a reasonable cost.
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.

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]
Air conditioner equipment power in the U.S. is often described in terms of "tons of refrigeration", with each approximately equal to the cooling power of one short ton (2000 pounds or 907 kilograms) of ice melting in a 24-hour period. The value is defined as 12,000 BTU per hour, or 3517 watts.[32] Residential central air systems are usually from 1 to 5 tons (3.5 to 18 kW) in capacity.
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