there is nothing wrong with it, most microwaves have that option and do not have to be vented out, even though as a contractor i prefer them to vent out. if the existing pipe already vents out, which it probably does if there is a pipe in the cabinet already. what you would have to do is unscrew the 2 or 3 screws in the top cabinet that screw down into the microwave ( if not there then there may be 2 bolts in the front of the unit behind the cover that have to be loosened) that will loosen the microwave, then its a matter of taking the screws out that hold the fan at the top back, pull the blower fan out and change the direction so that it faces up, screw the fan back to the unit and put the microwave back up and bolting it. check to make sure the fan connects to the duct work, if not, add a piece of sheet metal to connect and seal that joint. btw you may want to unplug the microwave before doing so, just for safety reasons.

Navy SEALs Lead and Win

Whether you know them ahead of time or not, any potential partner should be thoroughly researched before "sealing the deal".

Home had multiple offers, our letter to owner sealed the deal even though offer was not the highest How did you finance this deal?

There are often hidden costs--such as: engineer certification of the structure (depending on what the city requires) smoke damage to portions of the unit(s) that are "not affected" additional insurance during the rebuild, sealing the framing that has smoke, etc. 

Original is better and BIN is what is used on burned property to seal in the smoke smell.

Remediation is typically "encapsulation"...sealing, siding, painting over...but in some instances is needs scraped...that's a nightmare. 

Seal and paint over.

The water is currently dried up and I am working to get the property sealed. 

I had my contractor out to verify all areas are sealed of.