2026-02-02 – Weekly HVAC News : Storms impact HVAC components

Last week in our HVAC community, discussions centered around storm impacts on equipment, particularly the frequency of capacitor and contactor failures. Members also shared insights into airflow verification after sensor replacements, and debated the origins of the 400 CFM per ton rule. There was a lively exchange on how to reduce airflow noise without sacrificing comfort, and practical advice was shared on establishing effective installation habits from the first day on the job.


This Week’s Hot Topics

Storms killing caps and contactors
This thread delves into how recent storms have led to an uptick in capacitor and contactor failures. It’s an eye-opener for those dealing with frequent weather-related service calls.
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Verifying VAV airflow after sensor swap
A practical discussion on ensuring accurate airflow measurement following sensor replacements in VAV systems. This is critical for maintaining system efficiency.
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Origin of 400 CFM per ton
An intriguing debate about the historical reasoning behind the 400 CFM per ton standard. It’s a must-read for those interested in HVAC design principles.
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Quieter airflow without losing comfort
Explore solutions for achieving quieter airflow in HVAC systems without compromising on comfort. Handy tips for improving customer satisfaction.
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Day-one habits for quality installs
A guide on key habits to develop from day one to ensure quality installations. Perfect for those new to the field or looking to brush up on best practices.
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Low-flow accuracy on capture hoods
This topic covers the challenges of measuring low-flow rates accurately with capture hoods, essential knowledge for precise system assessments.
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Not a salt shaker, it’s 404A
A humorous yet informative thread discussing the peculiarities of handling refrigerant 404A, shedding light on common misunderstandings.
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Fill pressure on three-story hydronic systems
A technical discussion on the correct approach to filling pressures in multi-story hydronic systems. Valuable for those dealing with complex installations.
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Which contract clause saves the most
A deep dive into contract clauses that can lead to significant cost savings. Useful insights for anyone involved in drafting or negotiating contracts.
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Thanks for keeping up with this week’s discussions. If you have any thoughts or experiences to share, feel free to join the conversation. Keep up the good work!

I’ve seen a spike in blown caps after thunderstorms; my quick fix is adding an SPD at the condenser and using a contactor with an MOV/snubber, then checking L‑L voltage under load before the caps pop like popcorn. After a static sensor swap, I verify airflow with a hood or at least a quick ΔT/enthalpy check; 400 CFM/ton is just a starting point — humid markets often land around 325–350, but watch coil temp and comfort. “Treat every storm like a brownout test,” and if noise’s the gripe, drop the blower one tap and open another return, as @AlinaHVAC noted.

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After a storm, I’ve had success checking the circuit connections before replacing any blown capacitors. It’s like looking for the stray socks in the dryer before assuming you’ve lost one forever! Also, I find that checking the wiring insulation can save a lot of future headaches. @HVACGuy123 has a great thread on preventative measures that’s worth a read.

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I once found that installing a surge protector near the outdoor unit really helps reduce the risk of contactor failure after storms. It’s a small investment for peace of mind, especially with how unpredictable the weather’s been lately. Anyone else finding success with surge protection?

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