Oh, another thing, you never said if the dryer was gas or electric.  If
gas, where is this renovating dweller expelling the exhaust after moving
everything since the old exhaust to outside is no longer used?  Is he
also poisoning the utility access?  We have a gas dryer.  There is just
one exhaust (to the outside).  It carries both the dampened air from
drying the load of clothes AND any fumes from the burning flames.  Where
are the fumes going to go if the burner doesn't light or only partially
lights?  So this renovating dweller doesn't care about carbon monoxide
poisoning himself and the other residents, huh?  

Hot air in the dryer will convert synthetic materials in clothing to
styrene which when inhaled will cool and coat your lungs (aka popcorn
lungs aka bronchiolitis obliterans).  Dryer exhaust contains a
psychotropic drug (1,2Di-ethylene exachloride, a volatile organic
compound) when drying polymers; e.g., lycra when heated over 20 C.

Venting indoors using a gas dryer is toxous.  Venting indors using a gas
dryer is destructive (due to the high humidity).  Both still expel some
lint which becomes a fire hazard when accumulated.  It might only glow
when lit (remember there is hot parts to a dryer and someone working on
pipes in the utility access might be soldering pipes) so you start to
wonder "what is that burning smell" but it can cause a fire.  When you
next do a load of towels or blankets so you have a hefty wad of lint,
take a lit match to it.  You had better not be holding the lint in your
palm.  Have a buddy that is a volunteer fire fighter.  In a year, he
sees 2-4 fires, or more, or hears about them from other firefighters
that were caused by dryer lint (the home owner's didn't clean or replace
the exhaust tube, especially for forgetful owners that don't clean the
lint trap, or they let some lint drop to the floor where it accumulated
under the dryer).  Clothes burn.  Lint burns even better.  Flour will
burn and even explode if you hurl it into the air across a flame (go
lookup "flour explosion, see https://www.youtube.com/watch?v=iIkk0D2tUU8
to make a home made bomb).

https://www.usfa.fema.gov/downloads/pdf/statistics/v13i7.pdf
https://www.usfa.fema.gov/prevention/outreach/clothes_dryers.html
http://www.abcactionnews.com/money/angies-list/thousands-of-fires-are-sparked-e
ach-year-by-clogged-dryer-vents

If this renovating dweller thinks it is safe and they have a pet or a
kid, see if they will risk putting their pet or kid in the closet and
have the dryer exhaust into the closed closet.

I think the landlady needs to sic the housing inspector on this
code-breaking renovating dweller.
--- NewsGate v1.0 gamma 2