Heat Loss & Gain Calculator

Calculate room-by-room heating and cooling loads per EN 12831, ASHRAE Manual J, and CIBSE Guide A. Add envelope elements, set climate data, and get building-level summaries with peak room identification.

EN 12831 · ASHRAE MJ8 · CIBSE Guide A

Project Settings

Standard

Units

Design Location

Winter: -3.6\u00B0C

Summer: 28.9\u00B0C

Lat: 51.5\u00B0

Indoor Heating (\u00B0C)

Indoor Cooling (\u00B0C)

Room 1: New Room

Name

Floor Area (m\u00B2)

Ceiling Height (m)

ACH

Internal Gains (W)

Envelope Elements

Type

Description

Area (m\u00B2)

U (W/m\u00B2K)

Preset

Orient.

Ext.