Hugh Crowther
2021-02-26 07:47

The ventilation system often has a critical role to play in fire and smoke control and GOLD is up for the task. GOLD units have many options to help make your project as safe as it is comfortable.

Start with the Basics – Internal Fire alarm

GOLD units include internal temperature sensors that can be used as internal fire alarms as standard. In the Alarm Settings Menu, the Internal Fire Alarm can be activated at any time.  When activated, an alarm is initiated if the supply air temperature sensor registers more than 160 °F (70 °C) or when the return air temperature sensor registers more than 115 °F (45 °C).  The Internal fire alarm temperature limits can easily be adjusted via the IQNavigator (User interface). If an external Return air/Room temperature sensor is con­nected and activated, this works parallel with the return air temperature sensor of the AHU.  

The internal alarm reset can set to Auto – Unit will restart when temperature drops, or Manual – Alarm will need to be cleared manually before the unit will restart.

If there is an internal fire alarm, the supply and return Fan Operation at Internal Alarm can be set up to do the following;

Inactive – All fans off

Supply Air – Supply air fans will operate.  A further menu will appear prompting at what rate the supply fans will operate at  (0-100%)

Extract (return) Air – Return air fans will operate. A further menu will appear prompting at what rate the return fans will operate at  (0-100%)

Supply and Extract Air – Supply and return air fans will operate. A further menu will appear prompting at what rate the supply and return air fans will operate at  (0-100%)

Looking at the screen capture of Internal Fire Alarm Settings. The internal firm alarm has been configured as follows;

• The Internal fire alarm is On
• The internal fire alarm will trip if the supply air temperature reaches 70 °C or the return air temperature reaches 45 °C.
• If the internal fire alarm trips, it will require a manual reset.
• If the internal fire alarm trips, the supply fans will operate at 75% speed and the return fans will operate at 75% speed.

Activating the Internal Fire Alarm can be done any time and is a quick way to increase safety by having the GOLD unit shut down if it sensors fire in the supply or return air path. This information can be passed on via the BMS.

Set Your GOLD Unit Up For Active Smoke Control

Take advantage of your GOLD ventilation unit as a critical component of the building smoke management system. GOLD fans are tested for and can manage the operation for one hour at 160°F (70°C). 

By adding the TCBP Fire Bypass Section, the rotary or plate heat exchanger and air filters can be bypassed on the return side during smoke control operation. The TCBP is available for sizes 11 through 80.

The TCBP air bypass section is shown installed in a GOLD RX and PX unit with an additional return air damper. The dampers can be controlled by the building smoke management system to redirect air around the return air filters and rotor to allow smoke exhaust.

Use the External Fire Alarms for Advanced Smoke Control

GOLD unit controls include two External Fire Alarm contacts right on the main unit controller.  The two alarm inputs are at contacts 6-7 and 8-9. There are jumper wires as standard. If the circuit is interrupted (external contact) then the GOLD unit will go into alarm. The alarms can be hard wired directly to the fire and smoke management system or controlled through the BMS. It is possible to set the GOLD unit up to behave differently for each alarm.

The two external alarms settings follow the same parameters used for internal fire alarms including Manual or Auto reset, what fans will operate and at what speed.

For example, looking at the screen capture of External Fire Alarm Settings alarms have been configured as follows;

• The External Fire Alarm 1 reset is Auto
• The External Fire Alarm 2 reset is Manual
• If External Fire Alarm 1 trips, the supply fans will operate at 50% speed and the return fans will be off.  If the external alarm is cleared, the unit will go back into normal operation.
• If External Fire Alarm 2 trips, the return fans will operate at 95% speed and the supply fans will be off. The unit will stay in fire alarm mode until the alarm is manually reset.

The GOLD unit can have three different fire alarm modes and have all three trip at the same time. The Priority feature allows the user to choose which mode will be recognized. The options are Fire Alarm 1, Fire Alarm 2, Internal Fire alarm or Auto. Auto will recognize the first alarm to trip and stay with it. In the example shown above, Auto Priority has been selected.

Fire bypass in flow diagram

The fire bypass is shown on the hand-held terminal’s flow diagram when the function is activated. Fan operation for return air must be active for at least one of the fire alarms. Dampers switch to fire bypass if any of the fire alarms are active and the exhaust air fan is operational.

Swegon Smoke Detectors

In many cases, the external fire alarms are hard-wired to the building’s fire and smoke management system. In some cases, a standalone smoke detector is all that is required.   Swegon offers the TBLZ-1-72-a smoke detector. It is field mounted in the supply or return air duct and connected to either the External Fire Alarm 1 or 2. The GOLD unit can then be configured to respond to an external smoke alarm as described above. 

The Smoke detector also includes a separate alarm in the case where the sensor becomes dirty. This is connected to one of the GOLD units external general alarm inputs (separate from Fire Alarms) and will show up on the GOLD unit controller if the sensor needs cleaning.

Fire Alarm Settings

Summary

Taking advantage of the GOLD ventilation unit to enhance your fire and smoke management system couldn’t be easier. There are other options that can be done to fully integrate your GOLD ventilation unit into your fire and Smoke system including:

• Separate power supplies for a fan if they need to operate on emergency power  (consult Factory)
• Using the two General Alarm inputs (separate from the two Fire alarm Inputs)
• Integrating through BMS systems such as BACnet IP, Modbus, Metasys, Lonworks etc.

If you would like to try to configure a GOLD unit for yourself, go to the IQLogic Web demo here. Follow the log in instructions using installation user name and password and you should end up here;

With your mouse, click on the right edge and you should see this;

Click on Alarm Settings and you will see this;

Try it for yourself!

References

GOLD F Functions

TBLZ172 Smoke Detector

Manual for Alarms and information messages, Program Version 1.32

Function Manual – Installation, Program Version 1.32