Many people think that acclimation is just a myth or some industry mumbo jumbo aimed at diffusing potential product liability issues. But the fact of the matter is when installing engineered hardwood flooring, solid hardwood flooring, or even laminate flooring you must acclimate for as long as the manufacturer recommends.
If you choose not to acclimate your floors when installing engineered hardwood in any part of your house you run the risk of voiding your warranty. Not acclimating your floors could also lead to issues such as gaping and/or cupping.
So, remember no matter what your installer says, you have to acclimate your floors when installing engineered hardwood, solid hardwood, and laminate hardwoods. The reward of not acclimating is not worth the risk!