By the SightShield team · · 3 min read
Why Bangalore homes keep windows shut
Bangalore’s climate is mild, but the city’s growth brings constant construction, metro and road works, and heavy traffic. Dust settles on furniture within a day in many neighbourhoods, and homes on main roads deal with noise and vehicle fumes. Families respond by keeping windows closed and running the AC in bedrooms — which keeps dust out but traps stale air in.
Signs your home needs fresh air
- Bedrooms feel stuffy in the morning with the AC on all night.
- Condensation or musty smells in the monsoon.
- Fine dust on surfaces even with windows closed.
- Cooking smells lingering in the living area.
- A CO2 monitor reading above about 1000 ppm in occupied rooms.
Measure before you decide
A low-cost CO2 monitor is the simplest way to see whether a room needs more fresh air. Place it in a bedroom overnight with the door and windows closed and the AC on. Outdoor air is around 420 ppm; readings that climb well above 1000 ppm by morning show the room is not getting enough fresh air. A PM2.5 monitor shows whether outdoor dust and smoke are getting in, and whether filtration is needed.
Indoor Air Quality Monitors →How a system fits an apartment
In a flat, a compact ERV unit is typically mounted in the false ceiling of a utility area, passage or balcony, with two ducts to the outside wall and small ducts to the bedrooms and living room. Stale air is usually extracted from bathrooms and the kitchen area. Where there is no false ceiling, wall-mounted single-room units are an alternative for bedrooms.
How a system fits a villa
Villas usually have one unit per floor or a larger unit serving the whole house, with ducting in false ceilings or service shafts. Planning it during construction, alongside the AC and electrical layout, gives the neatest result and the lowest cost.
Plan fresh air for your home →Choosing the right system
| Home | Typical solution | Notes |
|---|---|---|
| 2–3 BHK flat with false ceiling | One compact ERV with ducts to bedrooms and living room | Unit in passage or utility ceiling |
| Flat without false ceiling | Single-room wall units for bedrooms | Each unit needs a wall opening |
| Villa or duplex | One ERV per floor, or a central unit with ducting | Plan with the AC layout |
| Home office or study | Single-room unit or a branch from the main system | Helps concentration during long calls |
Working with other systems
- Air conditioning: an ERV pre-conditions incoming air, so the AC load increase is small.
- Air purifiers: still useful for removing indoor particles; fresh air handles CO2 and odours.
- Central vacuum: removes dust at source and exhausts it outside, complementing filtered fresh air.
- Home automation: CO2 sensors can raise fan speed automatically when rooms are occupied.
Planning tips
- Keep the fresh air intake away from kitchen exhausts, generator exhaust and parking.
- Place intake and exhaust outlets apart so stale air is not drawn back in.
- Design supply grilles in bedrooms and living areas; extract from bathrooms and the kitchen area.
- Make filters easy to reach without opening the ceiling.
- Choose units with low noise at the speeds you will use at night.
Maintenance
Plan for pre-filter cleaning every few weeks to months and fine-filter replacement on the manufacturer’s schedule, more often during construction season in your area. The heat-exchange core is cleaned periodically. Make sure the filters are reachable without dismantling the ceiling.
Quick answers
Can fresh air ventilation be fitted in an existing flat?+
Yes, using a false ceiling in a passage or utility area, or wall-mounted units for individual rooms.
Is it noisy?+
A properly sized unit with ducting runs quietly at normal speeds. Units are placed away from bedrooms where possible.
Do I still need an air purifier?+
Often not for everyday dust with good filters, but a purifier can still help during very poor air days or for allergy sufferers.
Does it work during power cuts?+
Units can be connected to the inverter circuit, since their power draw is modest.
Will a fresh air system bring in mosquitoes?+
No. The intake has a grille and filters, so insects cannot enter the way they do through open windows.
Can it run all night?+
Yes. Systems are designed to run continuously at low speed, which is what keeps bedroom CO2 down.