CHILLED is a global scope, spatially explicit and physically based model for estimation of building space heating and cooling requirements. It combines high resolution climate data, building physics representation and socioeconomic and behavioural data. CHILLED is used for estimating long term growth in demand for space conditioning (heating & cooling), the associated energy demands and carbon emissions, and the population lacking cooling access (cooling gap).

Air conditioning units on the outside of a building in Hong Kong above shops. © Niall Kennedy | Flickr

Air conditioning units on the outside of a building in Hong Kong.

Projections of cooling gap from CHILLED model © Mastrucci | IIASA

CHILLED is linked to the STURM model (Building Stock Turnover Model), that integrates with MESSAGEix.

The model is based on variable degree days (VDD) (Al-Homoud 2001). The analytical calculations in VDD allow for a more accurate representation of actual balance temperatures of buildings, depending on the level of thermal insulation of the building envelope, efficiency of the heating and cooling systems. internal and solar heat gains, and other occupant behavior-related parameters.

The equations are run over a spatial grid at 0.5° grid resolution (approximately 50 km at the equator) at the global level and with daily resolution for a set of representative building archetypes with characteristics and thermal properties varying by region, housing type, and energy efficiency cohort. Results, by archetype, are population weighted; aggregated by location, country, and climatic zone; and associated with the respective geographical and housing categories in the STURM model.

More research on on heat, vulnerability & cooling

Publications using CHILLED model

Mastrucci, A. , Byers, E. , Pachauri, S. , Rao, N. , & van Ruijven, B. (2022). Cooling access and energy requirements for adaptation to heat stress in megacities. Mitigation and Adaptation Strategies for Global Change 27 (8) art.no. 59. 10.1007/s11027-022-10032-7.

Mastrucci, A. , van Ruijven, B. , Byers, E. , Poblete-Cazenave, M., & Pachauri, S. (2021). Global scenarios of residential heating and cooling energy demand and CO2 emissions. Climatic Change 168 (3-4) e14. 10.1007/s10584-021-03229-3.

Mastrucci, A. , Byers, E. , Pachauri, S. , & Rao, N. (2019). Improving the SDG energy poverty targets: residential cooling needs in the Global South. Energy and Buildings 186 405-415. 10.1016/j.enbuild.2019.01.015.