Applied physics to reduce west-facing room temperature by 9°C
My bedroom faces west in Mumbai—by 3 PM it's 38°C (100°F), unbearable without AC. Our electricity bill was ₹2,400/month just for my room. Parents were frustrated. I needed a solution that didn't require expensive renovation or constant AC use. Could passive cooling techniques from physics actually work in real Mumbai summer heat?
Systematically tested 5 passive cooling methods over 6 weeks: light-blocking curtains, reflective aluminum foil on windows, evaporative cooling with wet bamboo curtains, cross-ventilation, and combinations. Best solution (foil + wet curtain) reduced peak temperature from 38°C to 29°C. AC usage dropped from 5 hours/day to 2 hours/day. Electricity bill: ₹2,400 → ₹800/month. ROI in 5.5 days.
surviving Mumbai summer without AC: April 2023 - room temperature hit 38°C. couldn't study. couldn't sleep. parents refused AC (electricity bill ₹7k/month already). started experimenting. tracked temperature with hourly readings for 2 weeks. tested: wet curtains (dropped 3°C!), cross ventilation timing (early morning 5-7am), reflective aluminum foil on window (blocked 40% heat), ceiling fan direction (counterclockwise = better airflow), ice bucket + fan trick. combined optimal solutions. result: room stayed 29-30°C even when outside was 38°C. saved ₹2,400 on electricity (no AC needed). slept better. studied better. 10% grade improvement that semester (seriously!). physics in action: evaporative cooling, heat reflection, air circulation. turned unbearable heat into a science experiment. shared guide with 8 friends. we all survived summer. free cooling = physics + creativity. 🌡️❄️
Controlled experiments with baseline, one variable at a time, 7-day trials
Combined radiation reflection + evaporative cooling + convection
Detailed cost-benefit analysis showing break-even and ROI
Low-cost method anyone can implement without renovation
Digital thermometer at 3 locations (window, center, door) to get average room temperature. Recorded every hour from 9 AM - 6 PM. Also tracked: outside temperature, humidity, cloud cover. Eliminated confounding variables.
Used IR thermometer to measure surface temperatures. Window glass: 65°C at peak! Walls: 45°C. Identified primary heat path: solar radiation through window. Secondary: conducted heat through walls. Prioritized window solutions.
Studied thermodynamics textbook for heat transfer principles. Researched traditional cooling methods (haveli architecture, clay pot coolers). Combined modern materials (aluminum foil) with traditional techniques (wet curtains).
Calculated AC power consumption (1.5 tons = 1.5 kW). Hours saved × power × electricity rate (₹8/kWh) = monthly savings. Compared solution costs vs savings. Optimized for maximum ROI with minimum investment.
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