All russian tanks starting from T-64 (exept the early batchs and exported units of T-72) have overpressure system and air filtration kit for non-conventional weapon protection. It includes T-90S of course. THe Indian army chief once said that these tanks - were the second Indian strategic weapon, bcz in case of even nuc war the tank regiments would survive, and it would take only few hours to reach Islamabad suburbs.the other peripheral thing that the sight problem hilights is that these T-90's are obviously not NBC kitted - and that means utility and tasking restrictions.
The information about comparative tests in this article was took from this russian internet source (in english hovewer): http://armor.kiev.ua/fofanov/Tanks/TRIALS/19991020.html (it is one of the mirrors on a ukranian site).The article is about due to bad performance of T-72 in Gulf War, the Russians held a large-scale live round experiment on T-80U and T-90 to check the protection capabilities. ...In conclusion, the result is quite OK, at least not as bad as western predicted, and, it was T-90 whom had a better result
url origin article
url with google translator
Indeed, all Russian tanks starting from T-80, have tropicalised variant with compact internal AC system, that bring cool air just for tank crew. It's relative advanced system, taking in account the stiff space.I suspect that some idiot bean counter who is completely unaware of the sensitivity of modern electronics and who sees aircon as a luxury for the blackhats, has decided to save project money by culling the aircon option.
60degs cent will fry FCS and optics - it is not in the ideal operating range.
I seriously doubt that the russians can be blamed for this - esp if they have built the component to the end users specs. IMV The blame fairly and squarely lies with the failure of the Definition Team. (The arjun history supports it as well IMV)
Hovewer, the problem is, such system was'nt designed for electronnic stuff cooling bcz all russian electronics itself was designed for working in extremal conditions. As the T-90 developers say now, the french IR Catherine camera was asked by the customer as an undisputed last moment stipulation. Naturally, the tank with Catherine was not over all needed hot condition tests (like the remained parts of the tank were) . Now the russians offer more capable external AC device, that will be installed on the T-90 tanks going to Algeria and Libia. There is the pictures: