Blog – Catastrophe Response, Disaster Preparedness, Disaster Recovery, Water and Storm Damage

How Evaporator Coils Assist Disaster Recovery Teams

A large part of disaster recovery efforts involves temperature control. This is particularly true when it comes to controlling mold growth, creating the ideal environment, and promoting worker health and comfort. Disaster recovery equipment often contains evaporator coils that dry and condition the air by drawing out moisture and heat.

evaporator coil

How Evaporator Coils in Disaster Recovery Equipment Work

An evaporator coil removes heat and moisture from air with the help of a coolant chemical within the system. The coolant is a liquid that becomes a gas as it moves through a disaster recovery system. While it’s in its gaseous state, the coolant acts like a heat sink and traps heat from the air as a blower moves over the condenser coils. As the chemicals cool, the heated coolant returns to its liquid state and travels to an expansion valve, where it then reverts back into a low-pressure gaseous state. When the coolant chemicals enter the evaporator coils, the gas quickly cools. Fans blowing over the evaporator coils then cool the air.

Disaster recovery equipment may have separate condenser and evaporator coils, or coils that serve both functions. Common evaporator coil types include vertical coils, cased coils and uncased coils. Vertical evaporator coils are best for vertical airflows. Cased coils are similar to vertical coils, but have different shapes and sizes. Uncased evaporator coils are the simplest to modify because they lack a protective case.

Benefits of Evaporator Coils in Disaster Recovery Equipment

  • Dry air: Just as a glass filled with iced water collects beads of condensation, evaporator coils acquire drops of water that fall into a drain pan. The coils accumulate condensation because of the moisture in the conditioned air. Because cool air cannot hold as much water vapor as warm air, the moisture in the warm air that passes through the drying equipment condenses on the surface of the cool evaporator coils.
  • Improved indoor air quality: Evaporator coils in drying equipment help create an environment in which mold and bacteria cannot thrive or easily spread.
  • Equipment health: While an area that experienced water damage may have an HVAC system, this system is not designed to eliminate excess moisture after a disaster. The evaporator coils in disaster recovery units reduce the load on the existing HVAC system and prevent unnecessary wear, such as the formation of ice on the coils.
  • Increased comfort: Cooling coils work with other disaster recovery components to create an ideal drying climate, regardless of the weather outside. This optimal environment helps workers remain productive and healthy because they feel comfortable.
  • Controlled conditions: Clean coils and drains are essential to keeping a room dry and eliminating excess moisture. By maintaining the evaporator coils in your disaster recovery systems and not relying on an on-site HVAC system, you ensure the success of your team’s efforts and the performance of the equipment. By adding remote monitoring to the drying equipment, you’ll ensure the conditions are optimal for the recovery efforts.


Evaporator coils are the unsung heroes of disaster recovery equipment. Without them, moisture and warm air would persist, making restoration efforts more difficult. At Polygon, we offer a selection of the latest evaporator coils that work in tandem with heaters, chillers and desiccant dehumidifiers. Our expert engineers will gladly design a custom solution tailored to your needs to eliminate moisture efficiently and quickly. Talk to a restoration specialist today to learn more and schedule a free consultation.

[Photo from jblevine2004 via CC License 2.0]

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