Refrigerant Level Detection

not in the way you ask, no. there are no scales you can just add, you need to monitor pressure and the temperature the pressure was taken at to have a close idea. a sight glass will not be helpful in gauging this. to get an accurate pressure reading the system will have to operate against a load. unless a notable drop in pressure presents itself during maintenance there is no reason to weigh your charge. you might consider adding a dye to your refrigerant charge, if a leak begins to occur the leak will show up faster under a black light....this test could be added to your routine schedule with little additional cost and will not harm your equipment.

heres an example leak in a coil

1,000's of lbs?!? What type of chillers are we talking about, and how old, what is your maintenance program??? You should be keeping a daily log on every piece of equipment...at some point retubing is required...see page 44-...

http://www.njatc.org/downloads/TRC010EN.pdf

We have Five 5,000 ton Carrier single stage centrifugal chillers. 3 use R-143A and 2 use R-500. They were built in the 1970s. We keep hourly records of performance, and they are leak check externally weekly whether they are running or not. The normal charge on these units is 6,000 lbs of refrigerant. The tubes are cleaned and checked annually and have not been found to leak. If we had a real time indication of refrigerant level, we then may be able to identify time of losses ( starts, stops, gradual) and rate of loss.

Unfortunately the load varies, so a real time indicator is not likely to exist.....however it might be possible to build one, it would be an admirable feat...I would personally do an oil analysis and check the water for trace elements.....You did not mention the age of the tubing in the condensers...In any case you will probably end up calling in a specialist...Good Luck

nothing like the EPA for infinite wisdom, short of installing scales under each receiver and pumping the system down weekly you're going to have to interpret the requirement to match your needs and reality

Our machinery space is constantly monitored for refrigerant leaks. We have primary and secondary systems with level read outs, strobes, and an alarm line to a removal system in the event of a catastrophic failure.

We don't have any leaks.

Unfortunately for us, the machine space for these chillers is shared with five high pressure boilers and two steam turbine generators. A refrigerant detector system was installed as required by building code but it did not work. I stated that our target now is to monitor refrigerant LEVELS , not leaks. I am looking for information from someone who currently monitor vessel refrigerant levels. Thank you all for your input.

Depending on load conditions, refrigerant can migrate in and out of any vessel in a system, independent of any leaks. Thus monitoring refrigerant levels is not necessarily meaningful, except maybe for tracking the low points of successive cycles.

The idea of environmentally benign refrigerants should mean that leakage into the environment is of low importance. However, conserving expensive substances is economically rational.

it will always move away from heat and pursue the coldest spots as well

Exactly. My plant has vessels that can easily lose/gain 10,000+ pounds of ammonia in a few hours.