The HVAC industry has many manufacturers of units that all have heating and/or cooling coils as an integral part of their package. There are also many free-standing coils in large built up systems and some are mounted in duct runs from a central station unit. What they all have in common is the presumption that all the coils will meet the designated performance. They do...
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Almost all packaged A/C or split system units do not have a service factor for extra capacity. Even when new, these units may not yield the cooling BTUH capacity specified due to improper installation and/or incorrect load calculations at the inception of installation and startup. Consequently, as the system gets older and parts become less efficient, the system may lower its capacity to the point...
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Finned tube coils are meant to have contact with the air flow, as more contact creates more heat transfer. Heat transfer is nothing more than heat exchanged from one medium to another, and the goal is to create maximum heat transfer efficiency. The downside to this process is the coil’s susceptibility to foreign materials becoming lodged in them. The following explores this problem in a...
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HVAC and process heating/cooling must deal with the added tonnage created by using fresh air from outside. Most times, the requirement for fresh air is mandatory and can go from 10% all the way to 100 % of the system air flow. There are numerous rules and regulations written to eliminate air flow quality problems, including bacteria and other micro-organisms, that can cause health problems....
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Evaporator coils are a mystery to many technicians and engineers in the HVAC industry. Evaporator coils don’t have any movable parts, and a coil can have many different capacities based on what it’s fed from the refrigerant side of the closed refrigeration loop. If a self-contained unit is used to provide air conditioning in a space, the evaporator coil will have been engineered to match the...
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