[esp-r] Re: Network Flow Nodes and component connections

[Ryan Joseph Del Balso]

Jon,
Thank you.  That is much more clear as it was not explained in the
literature very well.
Ryan



-----Original Message-----
From: Jon Hand [mailto:jon at esru.strath.ac.uk] 
Sent: Sunday, October 19, 2008 10:03 PM
To: Ryan Joseph Del Balso; Paul Strachan; esp-r at lists.strath.ac.uk
Subject: RE: [esp-r] Re: Network Flow Nodes and component connections


If you are using a door connected to the outside then
to get the nodes on each side of the door at the same
height you will need to make the boundary node at the
same Z value as the room node rather than at the centre
of the door.

The door equations are based on the assumption that
the nodes on each side are at the same height. In
some physical spaces this is difficult to arrange.

A door can also be approximated via two openings
(one above the other) - and you would probably want
to setup a test model which could compare a door
component with two openings to find out if the two
approaches give the same predictions. If the zero
flow plane of the door is not at the vertical centre
then you might have to adjust the size of the two
openings.

-Jon Hand

-----Original Message-----
From: Ryan Joseph Del Balso [mailto:Ryan.Delbalso at Colorado.EDU]
Sent: Sun 10/19/2008 1:37 AM
To: Jon Hand; Paul Strachan; esp-r at lists.strath.ac.uk
Subject: RE: [esp-r] Re: Network Flow Nodes and component connections
 
Jon and Paul,
Thank you for your help.  This does clarify it better than the literature.
One more question though.

Jon, you said the door component works differently than the other
components.  This of course is what I am using.  I see that it is said that
the adjacent nodes should both be at the same elevation.  This confuses me,
because if I have a zone node set at the mid-height of the zone and a
boundary node set at the mid-height of my door, then I cannot have them both
at the same height and I will need a +ve and -ve connection adjustment.  I
still have to connect the door to a zone and boundary node so I don't
understand how this works.  Can you clarify this a bit more for me?
thanks
Ryan


-----Original Message-----
From: Jon Hand [mailto:jon at esru.strath.ac.uk] 
Sent: Saturday, October 18, 2008 6:30 PM
To: Paul Strachan; Ryan Joseph Del Balso; esp-r at lists.strath.ac.uk
Subject: RE: [esp-r] Re: Network Flow Nodes and component connections


Another point of view for flow networks...

During training courses my advise is:

a) imagine you are at the location of the air node
   in the room, look at the component. If above you
   then the delta height is positive. If you look
   down at the component then the delta height is
   negative. Do this for each component except for
   the bi-directional component (door).

b) One approach to networks is to create one boundary
   node for EACH opening/connection to the outside and make the
   height of the boundary node at the centre of the
   opening. When looking from the point-of-view of
   the boundary the delta height is zero.

c) Doors - one of the attributes of a door is the
   distance from the bottom of the door to the 
   adjacent nodes. When using doors in different
   size rooms you will have to make additional
   door components, each with a distance attribute
   that matches the specific room.  When using
   a door the delta heights are zero because the
   component already has the attribute set.

d) There are several exemplar models with flow networks
   look at those to check out these patterns.

-Jon Hand

-----Original Message-----
From: esp-r-bounces at lists.strath.ac.uk on behalf of Paul Strachan
Sent: Sat 10/18/2008 4:39 PM
To: Ryan Joseph Del Balso; 'esp-r at lists.strath.ac.uk'
Subject: [esp-r] Re: Network Flow Nodes and component connections
 
Ryan,

There is a diagram in Jan Hensen's thesis which shows the heights required
for the calculations. See page 4.10 in
http://www.esru.strath.ac.uk/Documents/PhD/hensen_thesis.pdf

Suppose you have a high level opening between 2 zones and that you specify
the connection as a linkage from node X ("positive" node) to node Y
("negative" node). The height of node X is typically placed at the average
height of the zone represented by node X, say 2 m above reference; similarly
for node Y, say 2.5m above reference.  If the high level opening is at a
height of 4m above the reference level, then the "Height of +ve linkage
point relative to node X" is +2.0m and the "Height of -ve linkage point
relative to node Y" is +1.5m.

If you had a further low level opening between the 2 zones, say at 1.0m
above reference, then for this connection, the "Height of +ve linkage point
relative to node X" is -1.0m and the "Height of -ve linkage point relative
to node Y" is -1.5m.

Regards
Paul

Ryan Joseph Del Balso wrote: 

	Can someone clarify the network flow node height and component
connection designations?  The cookbook describes placing the node at the
"height" of the opening, but does not define what that height should be.  If
I have a door opening, should that height be at the bottom of the opening,
the top or the middle?  Also, is the "Height of +ve linkage point relative
to node X" supposed to be from the bottom of the component to the node
height, or from the node height to the bottom of the component?  Same with
the -ve linkage node.  This would affect the sign.  Again, the cookbook and
reference literature do not describe this completely or clearly.

	 

	Additionally, the cookbook states that the nodes on either side of
the component should be at the same height, but what if you have a single
interior node and windows as multiple elevations?  Then only one of those
nodes could be at the same height as the internal node?  I am just a little
confused on this.

	Thanks

	Ryan