API · /ventilation-api

Ventilation & Airflow API

healthy 3,404 Subscribers

Ventilation and airflow maths as an API, computed locally and deterministically. The air-changes endpoint relates the air changes per hour, the airflow in CFM and the room volume — ACH = CFM × 60 ÷ volume — and solves whichever you leave out (the volume can be given directly or as length × width × height), reporting the airflow in cubic metres per hour too. The required-cfm endpoint applies the ASHRAE 62.1 breathing-zone rule, outdoor airflow = people × Rp + floor area × Ra, with sensible office defaults (5 CFM per person and 0.06 CFM per square foot), to size the fresh-air a space needs. The duct-velocity endpoint computes the air velocity in a round or rectangular duct from the flow and the duct size, V = CFM ÷ area, in feet per minute, metres per second and miles per hour, with guidance on whether it is in the quiet residential or noisier high-velocity range. Everything is computed locally and deterministically, so it is instant and private. Ideal for HVAC, building-services, indoor-air-quality and facilities app developers, ventilation-sizing and duct-design tools, and engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is ventilation and airflow; for heating and cooling load sizing use an HVAC API.

#ventilation #airflow #hvac #air-changes #duct #developer-tools

api.oanor.com/ventilation-api

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Machine-readable spec so AI agents can integrate this API.

/api/ventilation-api/openapi.json

/api/ventilation-api/llms.txt

Discovery: GET /api/index.json lists every API.

API health

healthy

Uptime: 100.00%; Server probes · 24h
Avg latency: 92 ms; Server probes · 24h
Subscribers: 3,404; active
Total calls: 28; last 7 days

Full status page → · 20 probes/24h

Pricing

Pick a tier — billed monthly, cancel anytime.

Free

2,000 calls / month
2 requests / second
Hard cap (429 above quota, no overage)
Air changes per hour (ACH) ↔ CFM conversion
Room volume from dimensions
Deterministic, instant results
2,000 calls/month

Starter

€9.00 /month

30,000 calls / month
5 requests / second
Hard cap (429 above quota, no overage)
Full ACH / CFM / duct-velocity endpoints
Required airflow for target ACH
Metric and imperial units
30,000 calls/month

Pro

€24.00 /month

150,000 calls / month
15 requests / second
Hard cap (429 above quota, no overage)
Duct sizing and friction-loss maths
Batch room and zone calculations
Higher 15 rps throughput
150,000 calls/month

Mega

€69.00 /month

750,000 calls / month
40 requests / second
Hard cap (429 above quota, no overage)
Highest volume for HVAC platforms
All ventilation and airflow endpoints
Priority 40 rps throughput
750,000 calls/month

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Frequently asked questions

Quick answers about pricing, quotas, and integration.

How do I get an API key for Ventilation & Airflow API?

Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Ventilation & Airflow API with the x-oanor-key header. No credit card needed for the free tier.

What's the rate limit for Ventilation & Airflow API?

Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.

How much does Ventilation & Airflow API cost?

Ventilation & Airflow API has a free tier with 100 calls / month. Paid plans start at €9.00 / month with higher quotas and faster rate limits.

Can I cancel my subscription anytime?

Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.

Is Ventilation & Airflow API GDPR-compliant?

All requests to Ventilation & Airflow API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.

Ventilation 3

Meta 1

Pick an endpoint from the list on the left to see its details and try it.

GET /v1/air-changes

Air changes per hour

Playground

Parameters

Custom headers

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GET /v1/duct-velocity

Duct velocity

Playground

Parameters

Custom headers

Language: Client:

GET /v1/required-cfm

ASHRAE required CFM

Playground

Parameters

Custom headers

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GET /v1/meta

Spec

Playground

Custom headers

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Code snippets

curl https://api.oanor.com/ventilation-api/SOME_PATH \
  -H "x-oanor-key: oanor_test_..."

const res = await fetch("https://api.oanor.com/ventilation-api/SOME_PATH", {
  headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();

$ch = curl_init("https://api.oanor.com/ventilation-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);

import requests
r = requests.get(
    "https://api.oanor.com/ventilation-api/SOME_PATH",
    headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())

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Ventilation & Airflow API

API health

Pricing

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Related APIs

Propane & LPG Tank API

Psychrometric Air API

Degree Day API

HVAC BTU Calculator API

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