Venting

 Then again, this may be a review of my (rental) apartment building.

We were told that vents were provided so that portable air conditioners could be connected and "exhaust" hot air to the outside.  I have learned some interesting things about the air conditioning vents in this building.  First of all, the fittings for those "vents" were never manufactured for, nor were they intended for, exhaust for portable air conditioners.  They are, in fact, intended to be the vents for *providing* cold air, from a central air conditioning system.  This isn't hard to figure out, or confirm, when you note the adjustable nature of the vents.  It's meant for a central air conditioning system, that is always on, so that the user can open or close the vents, or limit the flow, themselves.  This building does not have a central air conditioning system, despite having a heat pump for heating and hot water.

Those vents are not intended to be air return vents or exhaust vents.  Exhaust vents for portable air conditioners have a standardized hose size.  (Although that standardized hose size isn't standardized to anything else.)  It seems to be about 5 and 3/4 inches in diameter, and doesn't fit anything else like dryers or whatever.  But it does have a standard.  (At least it has up until now.  Now, air conditioners have standardized on a rectangular exhaust vent, which then connects to a round, possibly four inch hose, for venting through a window.  So the standardized air hoses for exhausting portable air conditioners will be changing in the near future, and it may become difficult to get the current sized hose.  But, in any case, it's certainly has nothing to do with the vents that we were shown as exhaust vents for portable air conditioners.)  The new, through window, exhaust venting hoses, will also not fit the vents that are installed in the apartment.

(The owner is now denying ever claiming that portable air conditioners could use the vents.)