HVAC Knowledge Hub

We recommend using the highest MERV-rated filter your HVAC system can handle without restricting airflow. This varies by system and can range from a basic filter to MERV 16 or higher. A system evaluation is the best way to determine the ideal filter without compromising performance.

This depends on the filter type, air quality, and system usage. In most active commercial buildings, filters should be replaced every three months. More advanced filtration systems, such as bag filters, may have different maintenance schedules.

Outdoor coils should be cleaned at least once per year. However, areas with high airborne particulates may require more frequent cleaning. Indoor coils typically don’t need cleaning if filters are changed regularly and the building operates under normal conditions.

Drain lines from the air handler and other HVAC equipment should be cleaned once per year. This includes clearing the line and treating it with an enzymatic solution to prevent clogs.

A well-functioning HVAC system that properly controls humidity should maintain:

• Cooling setpoint: 72-76°F
• Heating setpoint: 68-72°F

• We recommend Metal Oxide Varistors (MOVs) to safeguard high-voltage equipment from power surges.
• High-quality MOVs are replaceable and have status indicators to show if they are still functional.
• MOVs absorb damage from power surges, preventing harm to your equipment. Given their low cost compared to HVAC components, we highly recommend installing them on all major high-voltage HVAC equipment.

• Phase protection devices should be used on three-phase equipment to safeguard against:
  • • Phase imbalance
    • Over/under voltage
    • Phase loss
    • Phase reversal
• Some advanced phase protection devices feature fault indicators, making it easy to monitor potential issues.
• Given their affordability compared to HVAC equipment costs, we strongly recommend installing these on all three-phase HVAC units.

• For low-voltage systems, we recommend using fuse boards and Transient Voltage Suppressor (TVS) diodes.
• TVS diodes function like MOVs, protecting against multiple voltage spikes. They are cost-effective and easy to test.
• Fuse boards are especially useful when dealing with high-amperage risks, such as low-voltage cables exposed to outdoor elements like rooftop wiring.

• An optical isolator (often in the form of a repeater) should be installed to protect communication lines from transient voltage issues.
• Optical isolators prevent voltage spikes from damaging HVAC controllers by physically separating power sources.
• We recommend installing an optical isolator inside the building at every rooftop penetration for maximum protection.