Agreed. As Xubair said. Use clenil c and stay away from ventolin syrup, serious side effects. But as far as I think you said you are nebulizing with ventolin there is no need to combine ventolin with clenil. You can increase quantity of clenil in the nebulizing solution but by very little when you make it. You can give clenil three times. Also I am not a big fan of syp acefyl, its from a family of methylxanthines a compound found in tea to be specific theophylline, again theophylline has side effects. So need for any syrups in my opinion.
Please do get a pulmonary function test done. Please show your child to a good chest specialist as well. We have a brilliant drug for allergic asthma but quite expensive and last resort treatment if all else fails, xolair(omalizumab). Your child doesn't require it but thought that I should share it.
Wear a mask to prevent from dust.