Indoor

Steam Distributing Coil

There are many terms used in the HVAC Industry. One that is often misunderstood is heat transfer. Wikipedia’s definition states that heat transfer is a thermal engineering discipline that concerns the generation, use, conversion, and exchange of thermal energy between physical systems. It affects the measurement of heat.   The various heat transfer types are thermal conduction, thermal convection, thermal radiation, and the transfer of energy...

Read More

USA Coil & Air has been marketing our patented, freeze-damage water and steam coil line for over 25 years under the name Sentry Guard™. Sentry Guard™ is a one-of-a-kind invention that guarantees that any water or steam coil will not have freeze damage during a freeze event. What is a "freeze event"? Freeze events occur when chilled water, hot water, or steam heating coil has liquid in...

Read More
Hot Water Coil

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...

Read More
Duct Booster Coil

There are many existing systems that require the addition of cooling to a heating-only unit. Systems need to keep pace with changing requirements for spaces that include a mandatory requirement for cooling. Existing systems can already have cooling, but a booster will have to be placed into the system to add additional cooling.   When cooling is added, it must be decided whether the tonnage can be...

Read More
Fan Coil Unit

Many existing fan coil unit installations have inherent performance issues that relate to the original design and/or systemic conditions that decrease overall performance. Fan coil units are direct drive – the motor is directly connected to a squirrel cage fan. This arrangement clearly defines the volume of air based on external static pressure and the amount of dehumidifying at the chilled water coil. There’s very...

Read More
Industrial Coil

The generic terms “industrial “and “heavy duty” are used to describe an HVAC coil that has an arrangement and/or construction that creates quality heat transfer when adverse temperature, pressure, or a corrosive agent are present. Standard HVAC coils are constructed of copper tubes, aluminum or copper fins, and galvanized steel. The normal temperature for these materials is 250 degrees F and 200 PSIG pressure.   Enter Carbon...

Read More

Most HVAC steam heating coils operate with steam pressure below 25 PSIG, and a very large percentage are below 15 PSIG. These coils have specific piping and coil arrangement requirements to allow these systems to optimize performance and avoid systematic problems that require premature replacement.   Preheat coils in most of the country will require an arrangement that deals with below freezing air temperatures. In conjunction with...

Read More
Sectional Coil

Many heating and cooling coils are installed in air handling units with very limited access to the unit. This often occurs because the original designer didn’t give much thought to possible future replacement of the coils and fans. We have all seen ductwork, electric lines, water lines, boilers, chillers, pumps, and other air handlers where it’s impossible to install a new coil. The pull length...

Read More

It’s often difficult to understand circuitry on a chilled water coil. Changes to the “circuitry” and changes to the “tube diameter” will affect the overall capacity and pressure drops. Each time you change the circuitry on a coil selection, you have a positive, which relates to a higher capacity or lower fluid side pressure drop. The negative is either a lower capacity or a higher...

Read More