There is a difference in the SVG and the Schematic diagram. I also draw schematic diagram myself for each project.
The main problem in the EPlus convention is too many 'node names' which are not nodes. I am an EE person.
A resistor is a component. A capacitor is a component. Each can also be a branch. When you join them together, there is a node between them. This is the same as those shown in the schematic diagram originally attached with this e-mail. (all numbers,)
In the SVG and EPlus, the component is a node with a inlet and outlet node. (three node names) The actual connecting node names are not shown on the SVG diagram.
For example that you are connecting a fan and a coil together. The fan has three node names and the coil has three node names. The SVG shows the Fan followed by the coil.
If the outlet of the fan is not connected to the inlet of the coil in the branch, loop or connection, equipment list at least once, the loop is not complete. Of course, if you follow the list order in filling in the object this should not happen. When the links are not complete, there is no SVG output.
Why don't EPlus follow the simple node and branch rule of the EE or schematics.
Declare a two port, three port or n-port object. Define the function of the port for each object. Input, output, sensor, control, aux., etc.
When two components are connected together the node has the variable quantity that can be measured. The direction of the fluid flow is the output to input connection direction. The zone thermostat is a sensor node. The fan on/off is a control node. A schedule may be inserted between the sensor and the control node.
Now how to call this node junction. This node again has three possible names, a number, the output of the previous, and the input of the following branch. Are we back to square one with three node names at one point? Not really. If you use a number for this node, it may turn out to be the same number used in the .BND file.
The EPlus template object is moving towards this direction and letting the expansion program to do the detailing. I am using the .expIDF as a model to write my MACRO version of IDF, the .IMF.
Because the SVG diagram is not produced until the IDF is working, therefore, it would still be required to sketch a schematics first to make sure that all the output nodes are the input nodes of the following component/branch object.
By the way, the font size of the SVG file is set to 8, If you change this to 12, you will see the text larger in the bowser without zooming. If the names are too long and flow into the next box, you can shorten them by deleting some characters in the XML file using a text editor.
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
CC: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: haidermkhan@xxxxxxxxx
Date: Thu, 3 Jun 2010 11:57:52 -0700
Subject: Re: [EnergyPlus_Support] Schematics for Example Files
Haider Khan.
Great schematic! I always do the same when I am modeling with E+. Has anyone ever compiled schematics for all of the example files? It would be EXTREMELY helpful in understanding how the systems are set up if schematics were included with the example files. If there is no one on the E+ team that can do this, it could be crowed-sourced and done in a very short time. Does anyone else think that HVAC system schematics for the example files would save a lot of time?-Eddie
From: "James V Dirkes II, PE" <jvd2pe@xxxxxxx>
To: EnergyPlus_Support@yahoogroups. ; "Morss, Greg" <gmorss@tjeg.com com >
Sent: Wed, June 2, 2010 8:25:53 PM
Subject: [EnergyPlus_Support] Hospital with 100% OA and heat recovery
Dear Greg,
It?s very possible! I?m completing a model which uses the Heat Exchanger in the configuration shown on the schematic, and it is working well. My particular model does not use 100% OA, but I think all you?ll need to do is set up the Controller:OutdoorA ir object to have a minimum fraction which is always = 1 (something like what I?ve shown below).
p.s., The example files are helpful, but you have to wade through all of the node names to figure out what?s connected to what. I always make a schematic to help keep them straight.
<image003.png>
Controller:OutdoorA ir
Name
OAController_ Aquatics
Relief Air Outlet Node Name
NodeOut_EA_Aquatics
Return Air Node Name
NodeIn_RA_Aquatics
Mixed Air Node Name
NodeOut_MA_Aquatics
Actuator Node Name
NodeIn_OA_Aquatics
Minimum Outdoor Air Flow Rate
2.50132
Maximum Outdoor Air Flow Rate
13.21452
Economizer Control Type
FixedDryBulb
Economizer Control Action Type
ModulateFlow
Economizer Maximum Limit Dry-Bulb Temp (C)
29.4
Economizer Maximum Limit Enthalpy (J/kg)
82939
Economizer Maximum Limit Dewpoint Temp (C)
MT
Electronic Enthalpy Limit Curve Name
MT
Economizer Minimum Limit Dry-Bulb Temp (C)
-40
Lockout Type
NoLockout
Minimum Limit Type
FixedMinimum
Minimum Outdoor Air Schedule Name
Minimum Fraction of Outdoor Air Schedule Name
SchCpct_AlwaysOn
Maximum Fraction of Outdoor Air Schedule Name
SchCpct_AlwaysOn
Mechanical Ventilation Controller Name
Time of Day Economizer Control Schedule Name
High Humidity Control
Humidistat Control Zone Name
High Humidity Outdoor Air Flow Ratio
Control High Indoor Humidity Based on Outdoor Humidity Ratio
Heat Recovery Bypass Control Type
<image002.jpg>
It is contradictory to insist that future generations respect the natural environment when our educational systems and laws do not help them to respect themselves. (Let's do both.)
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