Evaporator

Airflow, airflow, airflow… When we set up and commission comfort cooling and heating systems, we need to pay more attention to airflow before worrying about the fancy controls or the refrigerant circuit. One way to do that is by checking out Bill Spohn's Airflow 101 webinar on ESCO Group's learning network, which you can access […]

Does setting a thermostat too low cause an air conditioning system set in cool mode to freeze? The answer is no, at least not directly. However, low evaporator load (low return temperature or low airflow) and low outdoor ambient temperature can lead to evaporator coil freezing. Low indoor setpoint can lead to low return air […]

When the quiz or the teacher asks what “latent” heat is, there is generally some reference to it being hidden heat, which is what the word “latent” means. We then learn that it is heat energy transferred that results in a change of state rather than a temperature change. Later on, we hear a lot […]

On occasion you will either find a furnace or be tasked with installing a furnace where the coil overlaps the edge of the furnace because the coil is wider. In the case of a Carrier CNPVP coil you need to ensure that you align the coil according to manufactures specs or you risk cutting off […]

On occasion, you will either find a furnace or be tasked with installing a furnace where the coil overlaps the edge of the furnace because the coil is wider. In the case of a Carrier CNPVP coil, you need to ensure that you align the coil according to the manufacturer's specs, or you risk cutting […]

This is a basic overview of the refrigeration circuit and how it works. It isn't a COMPLETE description by any means, but it is designed to assist a new technician or HVAC/R apprentice in understanding the fundamentals. First, let's address some areas of possible confusion:  The word “condenser” can mean two different things. Many in […]

In commercial HVAC, you will find several different types of multi-stage evaporator coils: intertwined (shown above), horizontal face split (one coil on top of another), and vertical (side by side). When staging a horizontal evaporator, pay attention to ensure that stage #1 is on the bottom and stage #2 is on the top. If stage […]