Ventilation and air flow B (T5)

Question 1

why bother with ventilation

Answer 1

 Oxygen
 Remove CO2
 Remove body odours
 Remove contaminants
 Fresh air provides us with a sense of well- being
 Remove moisture
 Removal of heat

Question 2

environmental control

- mechanical controls

Answer 2

1 - actuated opening windows
2 - cooling coils with dampers above = waste heater batteries
3 - heating elements
4 - acoustic transfer ducts

Question 3

environmental control - heating and fresh air ventilation

Answer 3

• Fresh air supply from plena • Pre-occupancy:
• 16°C in LW
• 21°C in occupied spaces
• Dampers control CO2 (1000ppm):
• ~ five settings in occ. spaces
• two settings (open/close) at stack outlets

Question 4

environmental control - passive downdraught cooling

Answer 4

• Outside air temperature of 22°C and rising
• Average structural slab temperature > 22°C • Average internal temperature ≥ 26°C
• No heating demand anywhere in the building
→
• Plenum dampers closed (good seal essential !!)
• Actuated windows operate to maintain CO2 then temperature

Question 5

commissioning in context

Answer 5

defining the control philosophy
designing the control system
installing the control system
setting the rock the control system
handover
fine turning the control system
occupant survey

Question 6

fine turning results

Answer 6

 Key points
 Actuators failed open!
 4 windows failed closed!
 Radiator valves found to be defective!
 Temp sensor missing on downdraught cooler!  Software conflict!
 Broadcast storm!
 Dampers above cooling coils locked closed!
 Heating engaged at 7am after night venting!

Question 7

3 C’s

Answer 7

control
commissioning
client

Question 8

control

Answer 8

Use of appropriate set points (different in summer / winter?) User control where appropriate

Question 9

commissioning

Answer 9

Test everything …. twice Commissioning should last 2 years!

Question 10

client

Answer 10

Does the client understand the intended operation?
Handover documents
Involve the client in design decisions