Picked up my 2010 RRS from local garage on Monday and after using the ac for the first time today, when I returned to the car after a couple of hours there was only what I can describe as a strong stale urine like smell.

was wondering if it maybe from the ac not being used for a while, or someone might be aware of another issue I may need to raise with the garage?

Any advice would be welcome.

That's why in future you should always always have the AC climate control in, just adjust the temperature, never turn it off. You have some water in the system somewhere which has gone stale. I am not sure how to fix it, I think you can buy (here anyway) an aerosol which you discharge in the car with the AC on recirculate mode. It's not cheap but it's worked for me when all I could afford was used Ford wagon which had a similar problem. Gone - 2008 Stornoway Grey RRS 2.7 TDV6
Gone - 2009 Buckingham Blue RRS 2.7 TDV6
Gone - 2010 Alaska White RRS 5.0 V8 Aspirated
Gone - 2017 Chawton White RRS 5.0 V8 Supercharged
Current - 2010 Java Black RRS 5.0 V8 Aspirated
Current- 2024 RRS P400 SE Dynamic

Thanks for the info. Will mention this to the garage, and see what they say.

Just had my AC flushed through and re-gassed. I think the garage charged me about £30 for the chemicals. 2006 RRS SC Bonatti Grey (the 55th car/van I have owned)
2005 GSX 1400 K5

I work in the HVAC trade (Heating, Ventilation, Air Conditioning)

There is a cooling coil which air passes over and cools the vehicles cabin. Through this coil passes the refrigerant at around 2 to 9 degrees C (Approx). With warm air passing over a cold coil (radiator grill) the coil sweats and drips. With this cycle going on over and over you get a build up of particulates on the coil. If the coil is unused for a while, the residue on the coil goes stagnant, which when the aircon is turned back on causes the odour in the cabin.

As for having the system flushed and re gassed................... This is a ploy to extract money from you for no reason. It's like saying you have to change the water in your heating system at home. They are both sealed systems, and should have all the correct gasses and oils/inhibitors to keep them healthy for life. Run the aircon for 10 minutes per month (Min) to stop the seals drying out, which will keep the refrigerant from leaking out through the seals.

Running the aircon system regularly is definitely advised to keep it in good working order. This applies to car, domestic and commercial systems.

Took car to garage today and they put whet they call a "bomb" into the car with all the windows closed and run the ac on full for a while with air on recirc.

When I collected the car later it smelt lovely and have left the ac on for the last 20 miles or so and its fine

Yep, that's what I was referring to. If I were you, I would buy another one and do it again, in my experience a larger car needs more than one treatment. Keep the AC on all the time from now on and just adjust the temperature. Gone - 2008 Stornoway Grey RRS 2.7 TDV6
Gone - 2009 Buckingham Blue RRS 2.7 TDV6
Gone - 2010 Alaska White RRS 5.0 V8 Aspirated
Gone - 2017 Chawton White RRS 5.0 V8 Supercharged
Current - 2010 Java Black RRS 5.0 V8 Aspirated
Current- 2024 RRS P400 SE Dynamic