Contact CFM Calculator
A result you don’t understand, a CFM figure that looks wrong, a feature you wish existed, or a partnership idea — this page routes your message to the person who can actually help. Every airflow question is answered by someone who can re-run the math and check your numbers.
Inbox Directory at a Glance
Sizing Help support@cfmcalculator.net | ~2 days | |
Corrections corrections@cfmcalculator.net | ~2 days | |
Product Feedback feedback@cfmcalculator.net | ~4 days | |
Partners partners@cfmcalculator.net | ~4 days |
Most replies within two business days — correction reports that affect calculator output are prioritized.
One inbox per purpose. Unsure? Use support@ and we will forward it.
Answered Already, Most Likely
Most CFM and ventilation questions are covered somewhere on the site. These are the destinations that resolve the majority of emails — worth a look before you write.
Pick the Right Inbox
Four routes, four inboxes — each one lands with someone who can act on it.
Sizing Help
Calculation & Results Support
A CFM figure not matching what you expected? Send your inputs — room dimensions or floor area, ceiling height, ACH, duct length and elbow count, safety factor, and unit system — along with the result you expected versus the result returned.
support@cfmcalculator.netCorrections
Report a Formula or Preset Error
Our engine runs the volume × ACH ÷ 60 math, duct friction and elbow losses, the ASHRAE rectangular-duct equivalent, velocity and noise checks, and unit conversion. If any output or guide statement disagrees with your hand calculation or the fan manufacturer's published curve, send the page URL and the exact numbers. We verify before changing anything.
corrections@cfmcalculator.netProduct Feedback
Feature Requests & Ideas
Want more scenario presets, an altitude or temperature correction, a static-pressure calculator, a printable fan schedule, or saved multi-room projects? We build around what HVAC installers, growers, and serious DIYers actually need on site.
feedback@cfmcalculator.netPartners
Partnerships & Trade Education
Fan and duct manufacturers, HVAC wholesalers, trade schools, apprenticeship programs, and ventilation associations — we are open to white-label licensing, classroom integrations, printed reference companions, and co-developed sizing tools.
partners@cfmcalculator.netWhat Happens After You Hit Send
No ticket numbers, no canned macros. Here is the actual path a message takes from your outbox to a verified answer.
Step 1
We Read It
A person reads your message — not a ticket bot. Messages with exact inputs (room size, ceiling height, ACH, duct length, elbows, safety factor, unit system) jump straight to the front of the queue.
Step 2
We Reproduce It
For anything numeric, we re-run the volume × ACH ÷ 60 math by hand and compare against the fan manufacturer's published performance data before we answer. Most airflow questions are resolved in a single reply.
Step 3
We Answer With the Math Attached
You get the explanation, the formula behind it, and — where relevant — the input to change. If we were wrong, the reply says so plainly and the fix is dated on the page it affects.
Step 4
We Keep the Receipt
Verified corrections and good feature requests feed directly into the roadmap. Your email stays with the thread and is never added to any list — there are no lists.
Quick Answers
The five questions we hear most from installers, growers, and DIYers.
How do I get a faster reply?
Include the exact inputs you entered — room dimensions or floor area, ceiling height, ACH, duct length and diameter, elbow count, and any advanced options (safety factor, unit system) — plus the result you expected and the result the calculator returned. That single message usually lets us reproduce and explain the difference in one reply.
Do you offer live chat or phone support?
Not yet. Email lets us verify every answer against the actual volume × ACH ÷ 60 math and the manufacturer's published fan data before responding, which matters when the topic is duct sizing and ventilation decisions. We read every message and answer most within two business days.
Can you tell me which fan to buy?
We can explain what the numbers mean — how a duct size change moves velocity, why elbows cost flow, how the safety factor behaves — but fan selection for a specific installation belongs to the manufacturer's performance curve and a qualified installer. Duct routing, make-up air, and code compliance are site decisions, not calculator outputs.
Do you sell fans, ducts, or tools?
No. The site sells nothing, carries no affiliate links, and is not affiliated with any manufacturer. Advertising is clearly labeled and separately handled — see the advertising section of the Privacy Policy for how that works.
Can I suggest a topic for the guide library?
Please do — that is exactly how the library grows. Send the question you were trying to answer, the room you were ventilating, and what you wished had been written down. Requests that describe a real job-site problem go to the top of the content queue.
Every email read by a humanPhoto: UnsplashWhat to Include for a Fast Reply
- 1Browser & device (for UI glitches)
- 2Exact inputs: room size, ceiling height, ACH, duct length, elbows — plus safety factor and unit system if changed
- 3The result you expected vs. the result shown
- 4Page URL or section title if a guide or reference looks wrong
Attach a screenshot of your calculator inputs if you can — it halves the back-and-forth.
Still need a human?
The three most-used inboxes, one tap away.