ESD design guide - Video and transcript
Dr Paul Bannister, Exergy Australia
Australian Government Department of the Environment and Heritage, June 2005
About the video file
This video should be viewed in the context of the ESD design guide for Australian Government buildings.
The ESD design guide gives a basic introduction to ecological sustainability issues and specifically how the built environment affects them. It begins by outlining the Australian position on Ecologically Sustainable Development (ESD) and some key policies relevant to buildings and ESD.
See also: more ESD design guide videos
One of the problems with air based systems is that they don't turn down very well. And when they get to this low load situation... they perform badly and get into all sorts of problems ... yet this is the situation for 80% of the year.
The passive question is the difference between 28 [degrees] and 24.
And if you say we're working with an active system, the difference between 23 and 24 is there, but its very much an incremental issue.
What's far more important is the difference between the heating set point and the cooling set point.
You get the situation where you've got 22 plus or minus 0.4, which is actually what most controls are set on.
That is much a bigger problem than whether its 22 or 23 plus or minus 0.4.
So getting some drift in there, which fits in very nicely with the idea that if its 34 degrees outside, its going to drift up to 24 and if its 10 degrees outside, its going to drift down to 21.
That has a very substantial impact.
The other thing that goes with this in terms of mechanical systems, it's a uniform question, is how well it turns down.
One of the problems with air based systems is that they don't turn down very well.
And when they get to this low load situation... they perform badly and get into all sorts of problems that pile up... yet this is the situation for 80% of the year.