Solar Shading Design: Kolkata, India

Direct answer

For Kolkata at 22.5626, 88.3630, the declination-only solar-noon altitude is approximately 89.1° at the June solstice, 67.4° at an equinox and 44.0° at the December solstice. Refine these geometry checks with the project date, civil time, facade azimuth, terrain and local horizon. The reproducible location record is GeoNames ID 1275004 in administrative area 28, at 22.5626, 88.3630; replace it with the surveyed parcel point before relying on the result. As a transparent geometry check, declination-only solar-noon altitude is about 89.1° at the June solstice, 67.4° at an equinox and 44.0° at the December solstice. Representative 21st-day geometry ranges from about 10.6 hours in December to 13.4 hours in June; this excludes atmospheric refraction, terrain and obstruction effects. The cited national authority is a discovery starting point; current local documents and a named qualified reviewer control project use of this solar shading design record.

Prepared by Harth · Topic-specific calculated asset and fresh SERP brief passed editorial screening; page remains noindex pending the independent content, evidence, similarity and link gates · Published 2026-08-26 · Updated 2026-09-02.

What must be verified for Kolkata?

Kolkata is represented here at approximately 22.5626, 88.3630 for discovery and workflow planning. A project address, parcel, elevation, exposure, authority, and submission date must replace that city-centre reference before design use.

How should solar shading design be established?

1. Fix the surveyed site and local time basis.
2. Select an authoritative weather source or a named solar-position algorithm.
3. Record period, percentile or scenario and units.
4. Test sensitivity to elevation, exposure, urban form and horizon.
5. Save the source file, retrieval date and checker in the model record.

What are the limits of this worksheet?

This shading-workflow page is a project-starting worksheet, not a design value or approval. The controlling authority and qualified professionals for the Kolkata site remain authoritative.

Kolkata horizontal-overhang screening worksheet

Kolkata overhang sizing hand check

P:H is projection depth divided by the vertical facade distance to shade, calculated as 1 / tan(solar altitude). For a 1.20 m vertical target, multiply the table ratio by 1.20 m. The 09:00 and 15:00 columns use apparent solar time and show the solar-profile-plane ratio; they do not resolve facade azimuth, horizontal shadow displacement or a side-fin geometry.

The Kolkata worksheet uses latitude 22.5626° and records longitude 88.3630°. A project study must replace the reference point, use the actual facade normal and obstruction mask, convert to civil time, test the full occupied period and account for diffuse sky, glazing and thermal performance. Refine solar positions with the NREL SPA.

Where can you explore related guidance?

• Explore all solar data guidance
• Sun Path: Kolkata, India
• Solar Altitude & Azimuth: Kolkata, India
• Daylight & Orientation: Kolkata, India
• Solar Shading Design: Jamshedpur, India
• All solar & daylight data guidance for India
• Climate Design Data: Kolkata, India

Sources and method

Location data from the GeoNames IN dump (CC BY 4.0, snapshot 2026-08-31, GeoNames ID 1275004). Regulatory starting point: Bureau of Indian Standards and the applicable state or urban local body. Figures are illustrative — verify against the current locally adopted edition for the site. Solar-method context: NOAA Solar Calculation Details; the Harth monthly table uses a simpler declination and geometric-daylight approximation whose stated limitations must be retained. Project-date refinement reference: NREL Solar Position Algorithm.

Source links

• download.geonames.org

• services.bis.gov.in

• gml.noaa.gov

• midcdmz.nrel.gov