Refrigerant Leak Detection

[Calador]

Hi,

I am a graduate now going into building services engineering. I am currently looking into leak detection systems for a cooling system connected to an Air Handling Unit (AHU) externally. Basically the AHU is on top of the roof and the condenser has to be external connected to the compartment where the evaporator lies via pipes.

The question i would like to ask is:
1) currently there are only sniffer detectors where it detects the concentration of the refrigerant in the air. I was wondering if there are any other systems which deviates from that concept(i.e. pressure drop within the pipes etc).

2) If i have to stick with the sniffer system, i would have to encase the connecting pipes so that any leak would not be blown away by the surrounding moving air. After sealing the ends of the encasement, is this sufficient enough for the detector to work efficiently?

3)I would be next looking into pump down systems. As far as I understand, the pump down is basically to pump the refrigerant into a vessel to temporary store it when you want to service the system or when there is a leak detected. I would like to know whether the pump down system is often incorporated in to the cooling system when you order them or must you separately order those with pump down system and contact the leak detection guy to hook up the detector to the pump down system.

Thanks for any feedback.

 

[bimr]

One assumes that you are talking about freon based refrigerants. Leak detectors are used to find very small leaks. There is generally not enough of a volume of refrigerant to use other leak detection methods. Also, comparatively, freon refrigerants have much lower toxicity levels and are nonflammable, noncorrosive, and nonreactive as compared with other refrigerants such as ammonia.

http://www.bacharach-training.com/methods.htm

If you hire a qualified refrigerant technician, he will have proper refrigerant evacuation equipment to remove the refrigerant.

 

[Calador]

I have read the contents of that link but all those methods suggest manual labour. I was looking for an automated system where the detector detects the leak then initiates the pump down mechanism to avoid any more leaking. BMS is then notified for someone to go up there to get it fixed. Only then will they use those methods mentioned in the link.

 

[bimr]

There are a number of companies that make automatic gas detection equipment. Try this one:

http://freonleakdetector.com/pages/beacon800.htm

 

[Calador]

Thank you. I will give them a ring. Just wanted to know the basic procedure for external application. Doubt any of these will work up in the roof where there are so much air movement.

There has to be an alternative if not all those plant rooms that are up in roofs will never have leak detectors installed.