Our grandparents kept homes livable through May without a single compressor, and their playbook still works — not as a replacement for the AC, but as the opening act that lets it work half as hard. Every degree the house sheds passively is money the meter never sees.
Run the house like a valve
The core skill is timing the windows. From late morning to sunset, the outside air is the enemy: windows shut, curtains drawn on the sun-facing side. After sunset, the direction reverses — open opposite windows to set up cross-ventilation and flush the day's heat out. The exhaust fan trick is criminally underused: run the kitchen or bathroom exhaust at night with a far window open, and it pulls a steady cool draught through the whole flat.
The window is the battlefield
- Heat that stops outside the glass is worth double heat stopped inside. Chiks — the bamboo roll-down blinds — outside the worst window beat any interior curtain.
- The khus curtain deserves its revival: sprinkled with water on a hot afternoon, it drops the incoming breeze by several degrees and makes the room smell like a hill station.
- Light-coloured, lined curtains on the sun side; the dramatic dark ones can live on the shaded windows.
Paint the fifth wall
Top-floor homes cook from above. A white reflective coat on the terrace — proper elastomeric cool-roof paint, or even the traditional chuna wash renewed each May — cuts ceiling temperatures dramatically. If the society won't paint, a shade sail or even a layer of dried palm fronds over the worst section helps more than it has any right to.
Small habits, real degrees
- Ceiling fans set to summer direction (anticlockwise from below) — half the homes we visit have at least one running backwards.
- The oven and the big bhuno dishes shift to early morning; the kitchen stops fighting the bedroom at night.
- Incandescent-era decorative bulbs retired — anything that glows warm is a tiny heater with a hobby.
Do the passive work first, and the AC — when it finally switches on at 26 with the fan spinning — is finishing a job the house already started.
