Agilent 8890 GC with 7012D TQ MS MMI, LN2 or Air Cooling

[supdas1]

Hi there, we recently purchased a new Agilent GCtqMS and waiting to be installed in November 2024. Unfortunately, we haven't considered MMI cooling need and didn't include cost in initial budget. What are you using for MMI cooling? What are the pros and cons of using LN2 and Air? The flow rate needs to be set at 200 ml/min and set pressure between 40-80 psi. I already have an air compressor unit that I use with GC-FID with set flow rate 200 mL/min and 80 psi pressure, with a trap and filter on (current compressor unit spec: Oil-free, hygienic, dry air
100% Oil-free air. Dry air down to -40 °C dew point. Tank Sizes:50Litre, Pump Displacement : 480 l/min / 17 cfm, Maximum Pressure:8 bar).
Requested a quote from Peak Scientific and quoted me for a new air compressor and zero air generator. The ETA won't suit the instrument installation plan and cost of the air generator and air compressor is eye watering. Any suggestion? Thanks in advance.

[andreen23]

Depending on the required cooling load and the ambient temperature, compressed air may not achieve the same level of precise, low-temperature cooling as LN2.
Geoguessr