Evaluation of thermal comfort in a historic building refurbished to an office building with modernized HVAC systems

ABSTRACT

Envelopes with low thermal performance are common characteristics in European historic buildings, causing higher energy demand and insufficient thermal comfort. This paper presents the results of a study on indoor environmental quality (IEQ), with special focus on thermal comfort, in the historic City Hall of Gävle, Sweden, now used as an office building. There are two modern heat recovery ventilation systems with displacement ventilation supply devices. The district heating network heats the building via pre-heat supply air and radiators. Summer cooling comes from electric heat pump ejecting heat into the exhaust ventilation air. A building management system (BMS) controls the heating, ventilation and air-conditioning (HVAC) equipment. The methodology included on-site measurements, BMS data logging and evaluating the occupants’ perception of a summer and a winter period indoor environment using a standardized questionnaire. In conclusion, indoor environmental quality in this historic building is unsatisfactory. Stuffy air, too high, too low and varying room temperatures, lighting problems and noise are constant issues. Although it is equipped with modern ventilation systems, there are still possibilities for improving thermal comfort by improved control strategies, since upgrading the building’s envelope is not allowed according to the Swedish Building Regulations in historic buildings with heritage value.

KEYWORDS:

• Historic buildings
• on-site measurements
• standardized questionnaire
• thermal comfort

Acknowledgements

The work has been carried out under the auspices of the industrial post-graduate school Reesbe, which is financed by the Knowledge Foundation (KK-stiftelsen).

The authors would also like to thank the staff at City Hall in Gävle for their contribution to this research through their replies to the questionnaires and Eva Edlund at City Hall for the related required coordination. In addition to this, we would like to thank Elisabet Linden for her technical support at the laboratory environment at the University of Gävle and Sture Johansson and Bengt Nyman at Gavlefastigheter AB for their technical guidance about the building energy management system of the City Hall in Gävle.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by KKS Knowledge Foundation: [grant number 20150133].