Ashrae and relationship with Other Air and Global Connectors??

[mariusvanwyk2216]

Hi All,

This has created a Conundrum for me. Please help me understand what the relationship and usibility of the Other air and Global connector is if Ashrae duct fitting types only support loss coefficient for Supply,Return, Exhaust and Common.

EXAMPLES

1. AHU that has a Supply and Return ducted and Outside air (Fresh air) not ducted with a damper on AHU.

The Connector for outside air then has to be a return connector with flow direction in calculated??

The Louvre in wall has return connector with flow direction out Preset.

2. AHU that has a Supply and Return ducted and Outside air (Fresh air) ducted with a damper on AHU.

The Connector for outside air then has to be a return connector with flow direction in calculated??

The Louvre in wall has return connector with flow direction out Preset.

or both have to be supply connectors.

a) What will it be to ensure general use of the Louvre ( Supply, Return, Fresh, Extract) or should one of each be created.

b) How and where is Other air and Global used and how does it affec the correct pressure drop calculations gotten from the Ashrae xml file in Revit.

Then the same question goes for the piping conectors Global and Other??? how is it used to achive correct flow and pressure calculations

Thanking all in advance and looking forward to response.

Regards

Marius

[julianjameson8403]

Marius

Have you looked on Kyle Bernhardt's blog (Inside the system) where he did two posts on connectors? These may help explain a little more the principle behind the Autodesk idea of conenctors. In response to your questions:-

1. Outside Air connector on AU will be Supply Air, Preset and In. Louvre on Wall will be mechanical equipment - not an Air terminal - and will be Supply Air, Calculated, Out.
2. As above. You need to create items with connectors set up for each type as you can't create just a Supply louvre and expect it to work for all systems. Revit won't let you cross connect generally anyway.
3. Ignore Other Air for use in HVAC systems. The Other Air connectors are used for things like compressed air, gas, medical gases etc.
4. Global connectors are usefully on things like circulating pumps, etc where you want them to be used on any system rather than having to create various versions of the pumps to cover the different systems, such as hydronic supply/hydronic return/etc. Global connectors are supposedly the only ones that can be linked so that the values pass from one connector to the other.

Have you reviewed the help file on the connector type descriptions to help explain where you would use Global connectors?

Regards

Julian