The Rev Michael Humphreys obituary | Research and development

In the mid-1960s my friend Michael Humphreys, who has died aged 89, joined the scientific civil service and began work at the government’s Building Research Station in Garston, Hertfordshire, on thermal comfort.

His colleague Charles Webb’s field data, gathered from Singapore, India, Iraq and the UK, showed that people were comfortable in widely different room temperatures, from the high teens in the UK to the mid-30s in Baghdad. Fergus Nicol joined the team in 1966 and together they developed adaptive thermal comfort research, focusing on the importance of different customs, behaviours and attitudes in different climates on the comfort of people in buildings.

Their findings clearly contrasted with the narrow temperature bands mandated in building standards by the air-conditioning industry, which were based on limited research in laboratory conditions. In 1972, Michael and Nicol presented their pioneering adaptive comfort theory at an international conference, and it now underpins global standards.

In 1978, Michael’s calling to the Baptist ministry took him from Garston to Regent’s Park College, Oxford. He was ordained as a minister in 1981 and moved with his wife, Mary, to Tring in Hertfordshire, serving first as pastor in the Baptist church there and later as pastor-secretary for the Hertfordshire Baptist Association in Dunstable.

In 1992, he returned to research with the Oxford Thermal Comfort Unit, attached to Oxford Brookes University, and found little progress had been made in adaptive comfort in his absence. National and international comfort standards were then dominated by narrow engineering comfort zones, leading to excessive energy use in, and emissions from, buildings.

Released by the church for two days a week, over the next 30 years he contributed to numerous field studies, research papers, books and the Windsor series of conferences on thermal comfort held from 1994 onwards.

Michael’s kindness, empathy and intelligence helped build a worldwide network of like-minded researchers, architects and engineers, enabling the development of the safe, comfortable, lower-energy buildings that are vital in our heating climate.

Born in London, Michael was the youngest of the three children of Helen (nee Paterson), a secretary, and Raymond, a chemist, and spent much of his childhood in Kent and Lancashire. Studying physics at Hatfield College, Durham, he met and married Mary Wood in 1959. After completing his diploma in education at Durham he spent seven years teaching physics at Hartlebury grammar school.

In 1996, Michael and Mary moved to Knighton in Powys, Wales, where he continued his research until 2020, while preaching in Welsh chapels. He wrote that he hoped his example would lead others to follow their deepest insights, and have the determination to “swim against the current” for which, he maintained, perseverance is definitely needed.

Mary died in 2023. Michael is survived by their four daughters, Grace, Catherine, Ruth and Hilary, 12 grandchildren and 11 great-grandchildren, and by his brother, Jonathan.