Stairwell Ventilation Project - Fraser Ave
There has been an increased demand in 3 to 4 storey walk-up apartments, generally being what most urban areas are doing. Yet, issues continue with the development of stairwell ventilation. It’s a simple solution that is easy to get right if you know what you are facing, but also easy to get wrong if you don’t. This case study highlights the stairwell ventilation project, Vent Supply supported on the North Shore.
The first Kiwibuild project on the Northshore uses slimline VL-55S louvres and ECF Series Grills to naturally ventilate the fully glazed stairwells. It’s visually appealing, requires no energy consumption and little in terms of maintenance. Even the issues of bugs being attracted to the lights at nighttime are considered and solved, with an incorporated bug screen.
The revitalised suburb of Northcote is just 8kms from downtown, Fraser Avenue comprises 102 apartments, spread across 5 buildings surrounding a village green. 70% of the studio, 1-, 2- and 3-bedroom apartments were reserved for first-home buyers.
This project transformed the often-claustrophobic feeling of stairwells, providing a connection between the interior and exterior of the apartments. The need for ventilation was found with the potential issues of fully glazed stairwells causing thermal discomfort. The sauna-like stairwells, makes trips up and down the stairs an unpleasant experience day to day.
To counter the lack of any interior convective air flow, the design incorporated VL-55S louvres into the window joinery. Visually, it is a very unobtrusive use of louvres, which for the most part will simply blend into the background and disappear from conscious sight. As a slimline louvre, the VL-55S was designed for effectiveness in small areas such as those at Fraser Avenue (or in louvred doors) and is particularly well suited to discrete placements. It offers a medium level of weather protection, has a low-pressure drop and is rated for air volumes up to 1.0m3/second. With the stairwells remaining lit at nighttime, insect screens were incorporated into the solution to prevent the area becoming full of flying nasties.
So, the second part of the natural ventilation solution called for ceiling grills in the stairwell ceiling to allow the naturally buoyant warmer air to travel upwards, out of the occupant transit area itself, then through those upper louvres. The ECF Series of fixed core, egg crate grills, provided a robust and effective solution and worked as intended. The rising, warm air could escape, and this helps suck in cooler air from outside, through the lower louvres. The warmer the air, the quicker it rises and faster it sucks in cooler air from the outside, making the solution effectively self-regulating as it adjusts to the conditions. No energy consumption is needed and little maintenance is required.
For the residents of Fraser Avenue, the naturally vented stairwells become the spaces defined in the architectural intent. They bridge the inside and outside and add to the experience of the apartment in a positive way.