[esp-r] Fwd: [ESP-r] night cooling / ventilation (from the old archive)

[Jon Hand (clcv10)]

An older message which newer users of ESP-r might not have seen....

A question on creating night ventilation:

> The night ventilation has the following two conditions:
> the zone temperatur > 24 °C and
> the ambient temperatur < zone temperatur
>
This control can be represented within a mass flow network
as three nodes and two controlled connections as follows:

a) an boundary node (wind pressure drive) "south",
b) an intermediate node "interm" (unknown pressure) to support
      the zone T > 24C
c) a node (unknown pressure) "zone"
d) a component to represent the window (such as a air flow opening)
e) a 2nd component (such as a slightly bigger air flow opening) for the
      zone T > 24C control logic
f) a bypass (crack component) going from node south to node zone.
    This is needed so that when the control is active there is still  
a  minor
    path from zone to an outside node (required for the solver).
   _____________________[ ]______________________
   |                               
crack                                  |
    
|                                                                        
    |
    *------------[ ]--------------------*----------- 
[ ]---------------------*
   south    window        interm     comp2         zone

Node interm should be set to track the temperature of zone.

You will need two flow controls.
f) a flow control to act on the connection between south and interm
    for this control you want to sense the difference between the node
    south and  the node zone
g) a flow control to act on the connection between interm and zone
    for this control you want to sense the temperature of zone

Only if both controls are satisfied will air flow from south to zone.

Test this model on a short simulation where the boundary conditions
and zone temperatures are likely to switch the controls. There is a
separate reporting facility for graphing flow within the network in
the results analyis package.

Regards, ESRU