hi all, not sure if this is the right place to ask..im planning to get a built-in oven..probably rinnai brand..to install it under counter...looking at the dimension of the space required for the oven to fit in, i have no problem for height & width...however, my cabinet depth is just 21.5" (546.1mm), looking at the website, the cabinet space required is 500mm and 50mm of ventilation space behind the cabinet (i supposed?)

so my question is, can the oven still fit in??? does oven need ventilation space behind??, even if have sufficient space to fit in the oven, the whole cabinet space behind is seal off, how is it possible to have ventilation for under counter oven??