Ac Atze Boerstra

Mechanical ventilation in recently built Dutch homes: technical shortcomings, possibilities for improvement, perceived indoor environment and health effects

This article presents the results of a Dutch national study into performance of mechanical ventilation systems and its effect on the self-reported health and perceived indoor environmental quality of occupants. Ventilation systems with natural supply and mechanical exhaust ventilation (MEV) and balanced mechanical supply and exhaust systems with heat recovery (MVHR) were investigated. Surveys were performed in 299 homes, which included visual inspections and measurements of ventilation rates per room and installation noise levels. An additional survey regarding perceived indoor air quality and self-reported health was completed per household. Results show that shortcomings are common in many homes and for both MVHR and MEV. Shortcomings include insufficient ventilation rates, high noise levels, unclean systems and insufficient maintenance. The causes have been found to be related to failures during all the different stages of the building process, from design to use. The indoor environmental quality was perceived more positive in homes with MEV when considering air quality, perceived dryness of air, noise and control options. There was no clear relationship between self-reported health and shortcomings of ventilation systems. Some practical implications are presented to avoid shortcomings in future dwellings.

Impact of Available and Perceived Control on Comfort and Health in European Office Buildings

The objective of this study was to find out how perceived control and access to control options like operable windows and thermostats affect the comfort and health of European office workers. For this, the Health Optimisation Protocol for Energy-efficient Buildings database was re-analysed. Statistical analyses were conducted to find out what the impact is of available controls on perceived control of building occupants. Furthermore, the effect of perceived control on comfort and health (building-related symptoms) of building occupants was determined. Overall, no significant correlations were found between available controls and perceived control. Solar shading, however, was an exception. On the other hand, between perceived control and comfort or health, multiple significant correlations were found. Occupants are more comfortable in buildings in which the amount of perceived control over temperature, ventilation and noise is high. Perceived control also has an impact on the incidence of building related symptoms, also if one looks at combinations of perceived control (e.g. control over temperature and ventilation).

Criteria for the indoor environment for energy performance of buildings

Purpose – To provide input data to design and energy performance calculations of buildings and ventilation, heating, cooling and lighting systems.Design/methodology/approach – European directive for energy performance of buildings was approved in the beginning of 2003. The transition period is 3‐6 years depending on the article. European Standardisation Organisation (CEN) has drafted several standards to help the member countries implementing the directive. One of these is the “Criteria for the indoor environment including thermal, indoor air quality (ventilation) light and noise.” The standard has been developed based on existing international standards and guidelines for the indoor environment taken into account the latest results from published research.Findings – The standard specifies design values of indoor environment, values to be used in energy calculations, and methods how to verify the specified indoor environment in the buildings. The paper describes some of the principles used in standards, a...

A new hybrid thermal comfort guideline for the Netherlands: background and development

In 2004, the first adaptive thermal comfort guideline was introduced in the Netherlands. Recently, a new, upgraded version of this ISSO 74 (ATG) guideline has been developed. The new requirements are hybrid in nature as the 2014 version of the guideline combines elements of traditional non-adaptive comfort standards with elements of adaptive standards. This paper describes the new guideline and explains the rationale behind it. Also changes in comparison with the original 2004 version and (some) issues related to performance verification are discussed. The information presented in this paper can be used by others (other countries) as inspiration material for new adaptive comfort guidelines and standards.

Personal control over temperature in winter in Dutch office buildings

A field study was conducted during the heating season in nine modern office buildings in the Netherlands. A first objective of the study was to investigate what kind of control Dutch office workers have over temperature in winter (available control), to map how often these controls are used (exercised control) and to identify how much control the office workers perceive to have over temperature in winter (perceived control). A second objective was to objectify the amount of control over temperature in winter with thermostat effectiveness measurements. The third objective was to investigate how available control and exercised control impact the level of control over indoor climate in winter as experienced by office workers (perceived control). The study consisted of (i) a systematic inventory of relevant building and HVAC system characteristics, (ii) a questionnaire among building occupants, and (iii) indoor climate measurements; concerning the latter, to evaluate the effectiveness of controls, dynamic experiments have been performed. These experiments consisted of manual adjustments of thermostats by the researchers. After these interventions, response times and step responses for room temperature were identified to quantify how effective controls were in changing room temperature. The outcomes of the study can be used to improve temperature control in existing and new office buildings.