When it comes to mechanical ventilation, one size never fits all. A small bathroom needs a whisper-quiet fan that barely sips power, while a warehouse, hospital, or commercial kitchen needs a duct fan capable of turning over thousands of cubic meters of air every hour. This is exactly the gap Astberg Ventilation has built its inline fan lineup to cover — starting from a compact 147 CMH unit small enough for a 4-inch duct, all the way up to 10,000 CMH systems engineered for large commercial and institutional spaces.
In this guide, we'll walk through India's widest airflow spread available under a single ventilation brand, explain how CMH (Cubic Meters per Hour) actually determines what fan you need, and show where the smallest and biggest options in the Astberg catalog fit into real-world use.
What Does CMH Mean, and Why Does the Range Matter?
CMH stands for Cubic Meters per Hour — the standard unit used to measure how much air a fan can move. It's the number you should look at before price, brand, or design, because an undersized fan simply won't clear moisture, odor, smoke, or heat fast enough, while an oversized one wastes energy and adds unnecessary noise.
A brand that only sells fans in the 150–800 CMH bracket can serve homes, but it can't help a facility manager sizing ventilation for a basement parking lot or a food processing unit. That's where having a catalog stretching from 147 CMH to 10,000 CMH becomes genuinely useful — the same trusted build quality and after-sales support scale with the project, whether it's a single bathroom or an entire commercial building.
The Smallest: Astberg Micro Jet AMJ100 — 147 CMH
At the compact end of the spectrum sits the Astberg Micro Jet AMJ100 Silent Mixflow Inline Fan (147 CMH), one of the smallest dedicated inline duct fans available in India today. Despite its size, it's built as a complete ventilation solution rather than a stripped-down basic fan.
Key specifications:
- Duct size: 100mm (4")
- Max. airflow: 147 m³/h
- Max. air pressure: 170 Pa
- Speed: 2600 RPM
- Voltage: 220–240V / 50Hz
- Net weight: 0.98 kg
- Body: Full ABS plastic construction (lightweight, sturdy)
Why it works well in tight spaces:
- Whisper-quiet operation — suited to bedrooms, home offices, and small bathrooms where noise matters
- Flanged intake and exhaust ends for tool-free assembly with standard vent hose and locking tabs
- Detachable housing and impeller, making cleaning and maintenance straightforward
- ETL-listed motor with automatic reset, protecting against overheating
- Versatile enough for grow rooms, basements, kitchens, and compact commercial nooks — anywhere odor control, humidity reduction, and steady air exchange are needed in a small footprint
For anyone comparing fans for a single room or a compact duct run, the AMJ100 is a good benchmark for what a small, well-engineered mixflow fan should deliver.
The Biggest: Commercial-Grade Mixflow and ERV Systems — Up to 10,000 CMH
At the other end, Astberg's ATMK Mixed Flow Fan Series is built specifically for commercial and industrial duct ventilation, where airflow requirements jump from a few hundred CMH into the thousands.
The ATMK range includes models like:
- ATMK300 — 3,150 CMH
- ATMK355 AC — 6,200 CMH
- ATMK400 AC — 7,100 CMH
These fans are designed for installation in compact mechanical spaces — either vertically or horizontally — making them practical for retrofit projects where ceiling or shaft space is limited but airflow demand is high. They're aimed at commercial kitchens, offices, retail spaces, warehouses, and any large enclosed space that needs continuous, high-volume air exchange.
For even higher capacity, Astberg's energy recovery ventilation system (the AHE-1000TL ERV) is rated at up to 10,000 CMH, combining HEPA, carbon, and dust filtration stages — built for homes, offices, hospitals, and hotels that need both high airflow and treated fresh air, not just extraction.
Together, the ATMK mixed flow series and the higher-capacity ERV systems represent the "biggest" end of Astberg's range — proof that the same brand offering a 147 CMH bathroom fan can also equip an entire commercial HVAC duct system.
How to Choose the Right CMH for Your Space
A rough way to think about it:
If you're unsure, it's always better to calculate air changes per hour (ACPH) for your room dimensions rather than guessing — Astberg's site includes a duct fan size calculator for exactly this purpose.
Why the Range Matters More Than the Single Product
The real advantage of a brand offering 147 CMH to 10,000 CMH in one catalog isn't just variety — it's continuity. A facility that starts with a few small inline fans for individual rooms can later standardize its larger duct runs and commercial zones on the same brand, same warranty terms, and same spare-parts ecosystem, instead of mixing suppliers as project scale grows.
Whether you need a single 147 CMH fan for a home bathroom or a 6,000+ CMH mixflow system for a commercial building, the underlying engineering — mixed flow impeller design, ETL-rated motors, and ABS/metal housing — stays consistent across the range.
Frequently Asked Questions
1. What is the smallest inline fan Astberg makes, and what CMH does it move? The smallest is the Astberg Micro Jet AMJ100, a 100mm (4") inline duct fan rated at 147 CMH (147 m³/h), with 170 Pa max. air pressure and a speed of 2600 RPM. It's designed for small bathrooms, home offices, and compact duct runs.
2. What is the biggest CMH inline/mixflow fan available from Astberg? On the commercial side, the ATMK Mixed Flow Fan Series goes up to 7,100 CMH (ATMK400 AC). For even higher capacity with built-in filtration, Astberg's AHE-1000TL energy recovery ventilation (ERV) system is rated at up to 10,000 CMH.
3. What does CMH mean in a ventilation fan? CMH stands for Cubic Meters per Hour — it measures how much air a fan can move in one hour. It's the primary spec to check when sizing a fan, more important than motor wattage or price alone.
4. How do I know what CMH fan I need for my room? A rough guide: 100–300 CMH for a small bathroom or utility room, 230–800 CMH for a domestic kitchen, 800–3,000 CMH for larger kitchens or commercial units, 3,000–7,000 CMH for warehouses/offices/retail spaces, and 7,000–10,000+ CMH for large commercial buildings, hospitals, or hotels. For an exact figure, calculate air changes per hour (ACPH) based on your room's dimensions.
5. Can the same brand cover both a small bathroom fan and a large commercial duct system? Yes — Astberg's catalog spans 147 CMH (Micro Jet AMJ100) to 10,000 CMH (ATMK series and AHE-1000TL ERV), so the same build quality, motor standards (ETL-listed), and warranty terms apply whether you're fitting one room or an entire commercial floor.
6. Is the Astberg Micro Jet AMJ100 suitable for continuous use? Yes. It has an ETL-listed motor with automatic reset to prevent overheating, a detachable housing and impeller for easy cleaning, and an ABS plastic body designed for long-term, reliable operation.
Explore the Full Range
- 👉 Astberg Micro Jet AMJ100 – 147 CMH Inline Fan
- 👉 ATMK Mixed Flow Fan Series (Commercial Duct Fans, 3,150–7,100 CMH)
Whatever the size of your space — a single room or an entire commercial floor — there's an Astberg fan engineered to match the exact CMH you need.
