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Building performance & science

I’ve been building a few HVAC calculators, and I’d like some feedback from the No Bull crew. They’re…

Discussion · Sep 26, 2026

I’ve been building a few HVAC calculators, and I’d like some feedback from the No Bull crew. They’re free to use, with no login required. • Filter Pressure & Airflow — Check clean-filter pressure drop and face velocity at your airflow. Search for a specific filter or compare filters, cabinets, and return-filter setups. https://filters.kalosflorida.com/ • Duct Check — Check duct sizes, room airflow, and return paths in an existing home to help spot restrictions and practical improvements. https://duct.kalosflorida.com/ • Dehumidifier Sizing — Estimate moisture-removal needs for occupied spaces, sealed attics, and encapsulated crawl spaces, then compare equipment using published performance data. https://dehum.kalosflorida.com/ This one is also on the HVAC School calculators page: https://www.hvacrschool.com/calculators/#dehumidifier-sizing-calculator Each has explanations to help you understand the inputs and results. Try them with a job you know well and tell me what you think. Do the results make sense? Is anything confusing, missing, or hard to use on your phone? If something looks wrong, please share which calculator you used, the numbers you entered, and what you expected to see. A screenshot helps. I’m still refining these, so honest feedback is welcome. Thanks for helping me make them more useful.

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Replies

Reply · Oct 12, 2026

https://deploy-preview-7--hvac-field-calculator.netlify.app/v2/field-calculator/ I’ve been building some similar calculators here. I’m interested in your duct version, it looks to be velocity aimed?

Reply · Oct 15, 2026

5-star initial rating on the filter performance / selection tool!

Reply · Oct 15, 2026

Awesome—looking forward to giving them a spin!

Reply · Oct 31, 2026

Bryan, thanks for putting these out free with no login — that's what gets a tool tried in the first place. One thing I look for, building software for small trade businesses: show the workings behind the answer. On the filter tool, if I can see the face velocity and pressure drop it used, I can check it against a filter I've already measured and decide whether I trust it. A number with nothing behind it is hard to lean on in front of a customer. Same test I'd run on the duct checker: feed it a house I already know and see if it flags the same restrictions I found by hand. If it does, that's when it earns a place on the phone.