The effect of a horizontal light pipe and a custom-made reflector on the user's perceptual impression of the office room located at a high latitude

Abstract

This paper describes a qualitative study on user opinion of daylight supplementation via a horizontal light pipe (HLP) applied in a test office in a building located in southern Norway. The study is part of a full-scale long-term study analysing lighting energy consumption and the photometry of supplemented light. This study employs a custom-made reflector for daylight distribution via HLP to preserve the features of natural light, noted as the primary human association with daylight, and is, as such, first of its kind. The main research aim was to find out if noticeable daylighting provision from the HLP leads to a positive user perception of the space when compared to a situation without a HLP. The study collects user responses to a new illumination solution using a user-survey method based on exposure to the visual environment of an experimental office. Statistical correlation and a t-test were used to analyse the results. The paper concluded that the user appraisal of the office was more positive when there was a noticeable daylight supplement from the HLP in the space, but the appraisal was negative for the higher light variability in the illuminance level both indoors and outdoors. The conclusion serves as an additional argument for the implementation of the HLP in building design, besides its energy saving potential.