This article is Part Three in a series of metal ceiling tile articles looking at the advantages of the product through a variety of applications. Part One explored an architect’s perspective at Darling Quarter project in Sydney. Part Two threw questions at a ceiling expert and unveiled the specific uses and limitations of metal ceiling tiles.
Architectus Director, Ray Brown says he would like to have used metal pan ceilings throughout the entirety of his award winning building, 1 Bligh Street, Sydney; it was only a budget that stopped him.
“If you could, you’d use metal pan ceilings everywhere, they have much greater longevity and they are higher quality, but they are more expensive,” he said.
Architectus recruited a host of sustainable materials and design elements for 1 Bligh Street which since completion in 2011 has achieved a 6 Star Green Star Office Design v2 and Office As-Built v2 Certified Ratings from the Green Building Council of Australia.
Chilled Beam System
One of those design elements is the building’s passive chilled beam system which requires a metal ceiling with perforations to facilitate its air-cooling function.
“Metal pan ceilings were an obvious choice because we needed to get the air circulation through the perforations and around the chilled beam system and back down into the space,” said Brown.
Light performance:
Brown used metal pan for the building’s perimeter zone which spans six metres from the glass windows to the first partition and around the entire elliptical building.
The perimeter zone not only hosts the chilled beams but also sees direct sunlight through the building’s glass façade.
Brown explained that the ceilings in the perimeter zone are stepped up to about 2.9 metres which increases the zones aperture and allows more light to penetrate the space. (see diagram from Architectus below)
When quizzed on the light performance of the metal ceiling tiles in 1 Bligh, Brown alerted attention to a design element that directly addresses the relatively low light reflectance performance of metal pan compared to mineral fibre options.
“We just increased the buildings aperture, light reflectance was therefore not an issue,” he said.
“We stepped the ceiling up at the edge just to get a bit more light in and create a bit more volume, it steps up to about 2.9 metres.”
Longevity:
Images: SAS International
Brown explains that other than the instance of a chilled beam system, metal ceilings are a superior product because of their longevity – a feature he believes he can prove.
“We’re actually looking at a project at the moment which involves some refurbishment,” he hinted.
“It has a 30 year old metal ceiling and it is in perfect condition.”
Acoustic performance:
^Paul McDonald from Armstrong says metal ceilings can achieve reasonable sound absorption performance with additional acoustic insulation pads. Image: Ceiling Tiles UK.
“On their own, perforated metal ceilings have no acoustic performance whatsoever,” says Paul McDonald from Armstrong, the world’s largest acoustical suspended ceiling manufacturer.
“They need some sort of an acoustic insulation pad to have any sound absorption at all.”
But Brown says that this is not a pressing issue for him when designing and that it can be solved quite easily.
“It’s not a big deal; if you need additional acoustic treatment you can get that [acoustic pad] on the underside of the slab above the tiles,” he said.
Brown’s Final Word?
“Typically you’d use metal pan if you’re doing a chilled ceiling system and you want quality and longevity, that’s pretty much the only reasons in terms of performance that you’d choose them.”