Harrow School Chapel, Middlesex, UKHistorical
The previous lighting installation was deemed unsatisfactory in all aspects. It consisted of ‘wagon wheel’ chandeliers utilising a ring of compact fluorescent lamps with a central mercury vapour lamp. The result was very low ambient and task lighting levels, and high glare factor. The overall lit effect was grey and cold.
To provide good ambient and task lighting to the Nave.
Provide high quality illumination in terms of warm colour appearance and high colour rendering.
To be as energy efficient as possible whilst allowing full dimming control.
Provide good lamp life and low maintenance characteristics.
Accentuate the architectural features to best effect including revealing the height of the roof structure.
Integrate with a flexible scene set dimming system.
Include for new emergency lighting.
A review of the conceptual options was explored from first principles. Whilst the clients were initially put off the use of chandeliers by how poor the existing ones performed, and also that chandeliers might provide visual intrusion to the interior, it became apparent that multi-task chandeliers would form the best basis for the new scheme. Attaching so many new luminaires to the building fabric was not an option for obvious reasons.
The solution for the chandeliers was to design a custom skeletal fixture to be as visually transparent as possible. However, this skeletal fitting was designed to incorporate six lighting elements.
1. Ambient and task downlighting from a reasonably accessible height for maintenance. The old scheme provided around 80 lux average over the pews but we knew that at least 120 lux was required to read a hymnbook. The new scheme achieves a maximum average of 220 lux.
2. Concealed uplighting to the roof to reveal the height of the chapel. This included integrated spotlighting to the stone corbels. All LED.
3. Accent lighting to architectural and interior features.
4. Decorative effect with a ring of halogen capsule lamps to provide sparkle and an essence of candle-light when dimmed.
5. Decorative effect and emergency lighting through the hand blown glass sphere with internal LED source.
The proportions and shape of the chandelier are made complete by the inclusion and position of the glass sphere.
To supplement the chandeliers additional lighting elements are:
a. Floor recessed uplights to accent the columns and capitals, and with adjustable uplights at the column capitals to uplight the arches, all LED source.
b. Uplighting to the organ pipes with concealed linear LED.
c. Accent lighting to the Angel atop the organ pipes. LED.
d. Lighting to the altar, choir, and apse with new column mounted tracklighting (LVTH).
e. Accent lighting to the choir screens with refurbished miniature decorative fittings, new LED source.
f. Uplighting to Apse roof with metal halide fittings on top of choir screens.
g. Wall washing to the memorial panels in the rear aisle with miniature recessed LED fittings.
h. New feature and reading lighting to the Pulpit. LED.
i. Miscellaneous LED fittings to provide ambient and accent lighting in the entrances and rear aisle.
All the above lighting elements are separately controlled and one of the main challenges for the project was how to minimise the cabling to provide the desired scene-set control and flexibility. A DALI system was utilised in a Mode Lighting scene-set system and although DALI is not a solution we would normally advocate for this type of project, the cabling advantages were an over-riding factor.
Photography Courtesy of James Newton