#fan laws

Tech Tips:

Replacing Residential HVAC Equipment With “Predictable Results”

When replacing a furnace or air handler for a customer, there is nothing worse than starting up the equipment and having it sound like the latest SpaceX rocket taking off. You insert your static pressure probes into the duct, and your stomach drops as you read the numbers. You realize the new high-end system you’ve […]

The 3 Fan Laws and Fan Curve Charts

This article was written by Tim De Stasio with Southern Comfort Consulting and Service. It was originally published on his blog, which you can access by clicking THIS link, but he permitted us to republish it on HVAC School as well. Thanks, Tim! It is critical for an HVAC technician to understand airflow and how […]

Blowers, Props, and How They Behave (or Misbehave)

Fan laws and fan curves are a deep subject with a lot of nuance and variation. Just to get our heads around the subject, let's focus on two different types of fans that we see all the time in HVAC: the prop/axial type and the radial/centrifugal type. Centrifugal/Radial As we increase the pressure differential across […]

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Bryan discusses surge protection devices (SPDs) with Mike from DITEK, focusing on practical applications for HVAC contractors and how to provide value to clients. Mike emphasizes that surge protection is essential for modern HVAC systems, particularly given that they are typically the most expensive appliance in a home and increasingly rely on sophisticated electronic components like variable-speed compressors and inverter boards.

The conversation delves into installation best practices, with a detailed discussion of proper wiring techniques for SPDs. Mike explains that surge protectors should be installed in parallel with the circuit, typically at the disconnect, and addresses common concerns about double-tapping lugs and ground connections. He emphasizes the importance of keeping wire lengths as short as possible and provides guidance for installations both with dedicated disconnects and panel-direct connections.

A significant portion of the episode focuses on DITEK’s Kool Guard (KG2) product, which represents an evolution in HVAC protection by combining surge protection with voltage monitoring. Mike explains how modern HVAC equipment, particularly inverter-driven systems, is increasingly sensitive to both over-voltage and under-voltage conditions. The Kool Guard monitors voltage on each phase independently and provides visual indication of fault conditions through LED indicators, making it easier for homeowners to identify potential issues without opening electrical enclosures.

Key Topics Covered:

· Why every modern HVAC system needs surge protection

· Installation locations and proper wiring techniques for SPDs

· The difference between line-side and load-side installation

· Ground connection best practices

· How to protect both condensers and air handlers

· The evolution from basic surge protection to voltage monitoring

· The importance of voltage monitoring for modern inverter-driven equipment

· How Kool Guard monitors voltage phase-to-ground vs line-to-line

· Common power quality issues beyond lightning strikes

· How to discuss surge protection with customers

· The limitations of utility-provided surge protection

· The impact of aging power infrastructure on power quality

· The advantages of USA-made surge protection products

· How voltage monitoring prevents damage from brownouts and over-voltage conditions

· The pre-programmed voltage protection ranges in Kool Guard

· Visual indication features for fault conditions

Learn more about DITEK at https://www.diteksurgeprotection.com/.

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