Recently in my brother in law’s home one Lloyd 3star 2 ton split ac installed. In the middle of installation heavy gas leakage(r410a) occurred and the servicemen called somebody over phone and by night another service personnel came with a gas cylinder and started topping up gas as in car ac. But as my knowledge r410 a is a composite mixture of two gases, so topping up is not correct method. Full system must be emptied by vacuum pump and then recharge with liquid gas for optimum performance. My brother in law asked the shop owner to replace the unit(since ac unit is coming from company as pre charged with gas correctly). But the technician told no problem. Slight variation in 2 ton ac may not be felt correctly by normal customer .But will definitely affect cooling efficiency and current consumption in long run. These type of cheating and malpractices are not good for customer and company.