Studio Matrx Monthly · Volume 1 · Issue 2 · July 2026
Amogh N P
 In loving memory of Amogh N P — Architect · Designer · Visionary 
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Dew Point Calculator

Find the dew point from the air temperature and humidity — the temperature at which moisture starts to condense. Any surface colder than this will sweat: AC coils, chilled-water pipes, radiant panels and cold windows. The science is psychrometrics.

30 °C
70%

Coastal / monsoon India often 70–90%; comfortable indoors is 40–60%.

18 °C
Dew point
0.0 °C

at 30°C & 70% RH, moisture condenses on anything colder than 23.9°C.

Surface at 18°C
Will condense / sweat

The surface is 5.9°C below the dew point — water will form on it. Raise the surface temperature, lower the room humidity, or insulate the surface.

This is why radiant cooling panels and chilled-water pipes must stay above the dew point in humid India — and why controlling humidity prevents sweating and mould.

A planning estimate. The dew point uses the standard Magnus approximation and typical surface temperatures; real values vary with local conditions and materials. Use it to understand and sense-check condensation risk — engineered dew-point control (for radiant systems, cold stores, cleanrooms) is qualified MEP/HVAC work.