2026-01-19 – Weekly HVAC News : Friday startup superstition origins

Last week, our HVAC forum was buzzing with insightful exchanges. Members delved into common HVAC superstitions, particularly the lore behind Friday startups, and debated the practicality of closing vents to save energy. There was also a strong focus on professional development, with discussions on the value of Continuing Education Units (CEUs) for CO2 and electronic expansion valves (EEVs). Meanwhile, seasoned techs offered advice to newcomers facing challenges with larger systems.


This Week’s Hot Topics

Origin of the Friday startup superstition
This thread explores the origins of the belief that starting up systems on Fridays is bad luck. It’s a fascinating look at how industry myths persist and influence practices.
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Closing vents: energy saver or myth
Are closed vents really helping your energy bill? This discussion weighs the potential savings against system efficiency concerns.
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Worthwhile CEUs for CO2 and EEVs
Professionals are evaluating which CEUs offer the most value for those working with CO2 and EEV systems. It’s a practical guide for continuing education.
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Where new techs stumble on big systems
Experienced techs share insights on where newcomers often face hurdles with large systems, offering tips to ease the learning curve.
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Which contract clause saves the most
Exploring which contract clauses can result in significant savings, this discussion is a must-read for those involved in negotiations.
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First-year apprentice — what to master next
Apprentices and mentors alike discuss the next skills to focus on after the first year, offering valuable career guidance.
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CE that actually cuts kWh/ton
This conversation highlights continuing education that directly impacts energy efficiency, with real-world applications.
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Origin of the 400 cfm per ton rule
Unpacking the history and reasoning behind the 400 cfm per ton rule, this thread provides clarity on a foundational HVAC principle.
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Thanks for being part of our community. Keep contributing your knowledge and curiosity as we continue to learn and grow together.

But i avoid ‘Friday startups’ unless remote alarms active; saw +0.2 in… w.c. when folks ‘close vents’.

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@taylor_jones76 I’ll still start on Friday if I can set a weekend ramp and a 2-hour trend — ‘bad luck’s just bad data’ — that’s how I caught an EEV hunting issue before it became a Sunday call. If the client insists on closing vents, I add a static-pressure alert at +0.15 in. w.c. above setpoint as a guardrail.

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