Making changes to mechanical systems

00:05

The system classification

00:07

is again set to supply.

00:09

But the flow direction is now set to out at the

00:12

connector as the flow of air leaves the fan call unit.

00:17

We saw previously how the flow of all air

00:19

terminals was calculated at the fan core unit.

00:22

This is because the flow configuration of the supply

00:25

fan core unit connector is set to calculate it.

00:30

A review of the return connector shows the same arrangement.

00:37

Finally,

00:38

the size of the connector is associated to corresponding family

00:42

parameters in the same way as the air terminal connector

00:48

close the fan

00:49

unit firmly without saving the changes.

00:54

In summary, a change to flow rate at any of the air terminals on the system

00:59

will result in a change to calculated values at the fan call unit.

01:07

The piping arrangement shown in this view is made up of an air

01:10

handling unit with a preset water flow rate of five gallons per minute.

01:16

And a Chia

01:17

whose flow rate value is calculated from the air handling unit,

01:22

change the value at the air handling unit to 10 gallons per minute

01:26

and the value at the chiller will be the same

01:32

select each of the pumps in this arrangement and

01:35

note the flow rates through both of them.

01:37

It can be seen that the total value in the

01:39

system has been divided between the two but not equally

01:46

open the pump in the family editor and review the connector configurations,

01:54

select the incon connector and note the flow configuration is set to calculate it

01:60

because there is more than one pump.

02:01

The configuration must be set to system so that the user

02:05

can determine the proportion of flow going through each pump.

02:11

You will see the flow factor parameter has now become active.

02:15

A value can be set here or it can be set so

02:18

that the user can control the parameter from within the project.

02:23

Select associate family parameter

02:27

and then create a new parameter called flow factor.

02:36

Make this an instant parameter

02:39

and group it under mechanical flow.

02:43

Then close the dialog box

02:47

carry out the same procedure for the out connection on the pump

02:51

setting the connector configuration to system

02:56

and then associate the flow factor parameter

03:03

for each connector.

03:04

Select associate family parameter

03:08

against flow.

03:10

Then create a new instance parameter called chilled water flow

03:15

and group it under mechanical flow

03:29

select OK. To close all dialog boxes,

03:34

load the family back into the project and overwrite the existing.

03:41

Finally

03:42

enter the mechanical settings

03:45

and disable the option for closed loop piping networks.

03:53

The flow factor parameter is used to control the proportion of flow to each

03:57

pump and set to naught 0.5 will divide the flow equally between the two.

04:04

A review of the flow rates for the pipework in the system shows

04:07

the same distribution of the available flow set at the air handling unit.

04:15

In this video,

04:16

we have looked at the importance of the application of system connectors

04:20

and connector configurations for a range of elements in a mechanical system.

04:25

Correct application will ensure the accuracy of

04:27

information such as flow pressure and velocity

04:31

information that can be used to establish pipe and duct

04:34

sizes and to assess the suitability of associated mechanical equipment.