Cooling load and duct design for a 420 m² outpatient clinic

Sehat runs nine family clinics. Their newest building in Sharjah opened last summer with split units bought on a "1 ton per 100 square feet" rule. The waiting room was 29 °C by noon, the minor procedure room never got below 26 °C, and two consulting rooms were so cold that doctors used heaters in July. The landlord has agreed to replace the system before the next summer, and the same design will be reused for a new branch in Nagpur.

The building is a single storey, 28 × 15 m, 3.2 m floor to ceiling, with an exposed concrete roof. The spaces are: - a waiting area of 80 m² for up to 25 people; - six consulting rooms of 14 m², each with a doctor, a patient and a companion; - a minor procedure room of 24 m² that must be held at 21 °C with 12 air changes an hour; - a 30 m² lab, a 22 m² pharmacy, a 16 m² staff room, toilets and a corridor.

The west wall has 18 m² of single glazing and the south wall 12 m².

You will produce a heat-load calculation and a duct design to the methods in the ASHRAE Handbook of Fundamentals and the ISHRAE data book. Use outdoor design conditions of 46 °C dry bulb and 30 °C wet bulb for Sharjah, 43 °C and 24 °C for Nagpur. Indoors, hold 23 °C and 50% relative humidity, except the procedure room.

You do not need site access. Everything is a calculation in a spreadsheet or Python, plus a single-line duct layout drawn in any CAD or drawing tool.

Done looks like a room-by-room load sheet for both cities, a fresh-air calculation, an equipment choice in tonnes of refrigeration (TR) with a reason, a duct layout with sizes and velocities, and a short design report the landlord's contractor can price from.