Coils and Counter-flow: 5 Common Questions
The first thing to remember about coils and counter-flow is that chilled water coils are always built to be piped in counter-flow. This means that the air flows in the opposite direction as the water. For example, with counter-flow, the air flows through rows 1-8, while the water runs through rows 8-1. Water always travels through the coil in the opposite direction of the air; hence the term “counter-flow.” Direct Expansion Coils (Evaporator Coils) are also piped in the same manner.
Steam Distributing (Non-Freeze) Coils: The Accidental Coils
Were you aware that Steam Distributing coils or “Non-Freeze” steam coils were essentially discovered by accident? At the inception of the HVAC industry, steam coils were originally designed to be shorter in length because there was not a good way to evacuate condensate. In an effort to make steam coils longer in length, the concept of a steam coil containing a tube within a tube was invented.
Guidelines For Air Velocities
Step # 1 in determining the size and performance of a coil is dependent upon understanding face velocities of air across the coil. Whether you use CCA’s coil selection program to help size the coil, or you are replacing an existing coil; the height, length and resulting velocity determine everything.
Why Is Fin Design On HVAC Replacement Coils Important?
What is the point of understanding the importance of fins in HVAC replacement coils? While coils can be built with flat fins for various reasons, the vast majority of coils are built with enhanced fins. Enhanced fins help to ensure that the airflow is not running straight through the coil.