Daikin VRV system and Fire Alarms

[ChrisF11]

I recently designed and had installed a four pipe Daikin VRV system that came on line last month.

The temperature control is very good and despite the odd complaint about it being too cold it has been trouble free.

There is one problem however, which is in certain areas we are having spurious fire alarms. Since the system came on line we have had three and I have now been tasked with resolving the problem.

Each alarm has been in one of the closed offices and the sensor has been a smoke alarm quite close to the grille diffuser.

Additionally the alarms appear to be preceded by a change from hot to cold as the vapour compression cycle is reversed.

My personal belief is that the sensors are too sensitive and too close to the diffuser but before I get them moved I would like a second opinion.
Has anyone come across this issue before?

Regards

Chris

[Brian_UK]

Sounds like the cause.

A rapid change of temperature can upset some sensors. I believe that fire detection sensors are meant to be in reasonably 'static' airflow.

Condensation from the cooled air could also upset them.

[install monkey]

daikin 4 pipe! - were the smoke detectors covered when the install was happening?
blank off 1 side of the grille so it doesnt blow onto the detector