In the heart of Delhi’s worsening pollution crisis, one clever resident decided to skip the premium air-purifier route and build his own. Using off‐the‐shelf parts for roughly ₹2,000, he claims to have reduced his indoor air quality index (AQI) from around 400 to just 50 in under 15 minutes.
Here’s a deeper dive into the build, why it matters, how it works, and whether it’s really the smart alternative it appears to be.
The Build: Simple Parts, Smart Design
According to the Reddit post shared and picked up by the media, this is what the builder used:
- A 150 mm exhaust fan (~₹750)
- A HEPA filter purchased online (~₹1,000)
- A switch/regulator + wiring (~₹65)
- Cardboard body + glue gun (~₹150)
He placed this setup in his ~12×12-foot room and reported that even at the minimum fan speed, the AQI dropped from ~380 to below 50 in less than 15 minutes.
What stands out:
- He used HEPA filtration — important for capturing fine particles.
- He selected a manifold design: simple fan + filter, but sized properly to his room.
- He prioritized cost-effectiveness and speed over brand labels.
Why It’s Important
With winter smog and high pollution levels in Delhi and surrounding regions, indoor air quality becomes critical. He built something at an extremely low cost in contrast to expensive commercial units. It highlights a shift: Consumers no longer need only big-brands to attempt serious purification. Powerful DIY alternatives are emerging. For those living in small to medium rooms, especially in apartment settings, a focussed build could deliver meaningful improvements.
What It Does Exactly
The exhaust fan pulls air through the HEPA filter, removing particulate matter (PM2.5/PM10) and some finer dust. The relatively high airflow (due to fan size + filter surface) means a large volume of air is cleaned in a short span, contributing to the rapid AQI drop. By maintaining minimal fan spee,d the builder also suggests it’s feasible without unmanageably high noise or power consumption.
Things to Consider & Limitations
- Filter quality matters: “HEPA” is a broad term — performance can vary. For serious pollution (gases, VOCs) you’ll need activated carbon + gas filtration layers.
- Room size and layout: His claim is for a 12×12-foot room. Larger rooms need proportionally larger fans/filters to deliver similar improvements.
- Noise & energy: Even at low speed a 150 mm fan will generate sound and consume power — maintenance of comfort matters.
- Maintenance & replacing filters: DIY builds may bypass brand service-support; filters will need regular replacement to maintain performance.
- Certification & safety: Commercial purifiers come with electrical safety certifications, sealed units etc. A DIY build needs careful wiring and safety checks.
- Gas & chemical pollutants: This build appears heavily biased to particulate removal. If your indoor air has high VOCs or gas pollutants (NO₂, formaldehyde) you’ll need additional filtration.
Why This Works & Its Broader Implication
The cost-to-performance ratio is compelling: For ~₹2,000 you get “good enough” indoor air quality for a room — that’s far cheaper than many branded purifiers which cost considerably more. It signals a democratization of indoor-air solutions — tech/hobbyist angle meets real-world need.
For you, as someone interested in hardware, modding and building (you’ve worked on PC hardware, DIY game dev, etc.), this story aligns well with your audience: Build-it-yourself, optimisation, component choice. It opens up article angles: “How to build your own air purifier under ₹3 000”, “DIY vs Commercial – what you trade and what you gain”, “Filter types explained – which one to pick for your room size”.
