Door Draught Saving Calculator
A draughty door lets your cooled air leak out and hot, humid air leak in — so the AC works harder. Enter the gap size, door size, climate and your AC habits to see the indicative annual ₹ saving from sealing the gaps — and how fast the weatherstripping pays for itself.
The draught
Clear airflow; dust line on the floor. Long, fierce summers. Leak perimeter ≈ 6 m → about 360 cm² of open gap. Indicative India 2026 — a real draught varies with wind, pressure and how the door sits.
Indicative annual saving from sealing this door
₹0/yr
Payback on a ₹350 seal: 3.2 months
Saving / yr
₹1,310
Energy saved
164 kWh
per year
Payback
3.2 months
seal ₹350
Cumulative saving vs one-time seal cost
Where the green line crosses the dashed terracotta line, the seal has paid for itself.
How much the gap size matters
Annual saving from sealing, for a small / medium / large gap — at your door, climate and AC usage. Bigger gaps leak far more air, so they save far more once sealed. Your selected gap is highlighted.
Seal it the right way
DesignAI can suggest the right weatherstripping and bottom seal for your door, sense-check the saving, and flag if the gap points to a deeper problem (a sagging or binding door).
Assumptions & the fine print
- This is an indicative estimate, not a measurement. Real draught loss swings with wind, the pressure difference across the door, and exactly how the door sits — so treat the ₹ figure as a ballpark, and confirm the gap on site.
- Model: leak area = average gap × leak perimeter (two jambs + head + bottom); the AC re-cools the incoming hot air (sensible heat) plus a humidity uplift for Indian outdoor air; electrical energy assumes a split-AC COP of ~3.0.
- A good weatherstrip plus a door bottom seal is assumed to stop about 70% of the leak — not 100%. A worn or badly fitted seal stops less.
- Seal cost is the consumable (weatherstrip / door sweep), typically ₹100–600; add 18% GST on goods, and a small carpenter charge if you have it fitted.
- If the gap is uneven, the door rocks, sticks or won't latch, the cause may be structural (a sagging leaf, a dropped hinge or a swollen door) — sealing alone won't fix it and a carpenter may be needed. This tool is DIY guidance, not a substitute for one.
Related Guides — Deep-dive reading
Gap Under Door Fix: Seal the Bottom Gap (India 2026)
Why the gap under your door matters and the ranked fixes — sweeps, draught excluders, threshold strips and drop seals — with prices and steps.
Home Doors & EntrancesHow to Stop Door Draughts: DIY Sealing Guide India 2026
Seal the four sides of any door to block draughts, dust, insects, noise and AC loss — a step-by-step DIY guide with Indian prices.
Home Doors & EntrancesAir Curtain Doors in India 2026: Sizing, Velocity & Spec
How air curtains form an invisible barrier at open entrances—cutting heat, AC loss, dust and insects—plus sizing, velocity and IS/AMCA context.
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