Relevant: In what year did venting bathroom exhaust out of the house become a code requirement?
I am NOT a lawyer or an inspector. The relevance of these codes and CA law are my own interpretation.
Going all the way back to IRC 2000: (Italic emphases; mine)
R303.3 Bathrooms Bathrooms, water closet compartments and other similar rooms shall be provided with aggregate glazing area in windows of not less than 3 square feet (0.279 m²), one–half of which must be openable.
Exception: The glazed areas shall not be required where artificial light and a mechanical ventilation system are provided. The minimum ventilation rates shall be 50 cfm (23.6 L/s) for intermittent ventilation or 20 cfm (9.4 L/s) for continuous ventilation. Ventilation air from the space shall be exhausted directly to the outside.
M1501.1 Outdoor discharge. The air removed by every mechanical exhaust system shall be discharged to the outdoors. Air shall not be exhausted into an attic, soffit, ridge vent or crawl space.
NACHI -Dryer Vent Safety:
M1502.2 Duct termination. Exhaust ducts shall terminate on the outside of the building or shall be in accordance with the dryer manufacturer’s installation instructions. Exhaust ducts shall terminate not less than 3 feet (914 mm) in any direction from openings into buildings. Exhaust duct terminations shall be equipped with a backdraft damper. Screens shall not be installed at the duct termination.
"Dryer box"? According to google that's a giant, recessed cover plate for the exhaust duct. They told you to make a bong for your dryer? WTF...
The building itself may be grandfathered, but any dryer installed E.g., since 2006 must have met the 2006 IRC (and possibly codes preceding that date). What's the year of manufacture on the dryer and the exhaust fan? It doesn't matter when the building was built. What matters is the install dates on those items.
What can you do? Have a hole cored and run a dryer vent: (Note- The amount deducted cannot be more than one month's rent. You should discuss this with your landlord. Proceed rationally; no one wants to pay lawyers money. And if you decide to push, and they shove back: If laundry is not stated in your lease, removing the unit solves the landlords liability -and removes your ability to clean clothes.)
Before renting a rental unit to a tenant, a landlord must make the unit fit to live in, or habitable. Additionally, while the unit is being rented, the landlord must repair problems that make the rental unit unfit to live in, or uninhabitable.
implied warranty of habitability - a legal rule that requires landlords to maintain their rental units in a condition fit for human beings to live in. A rental unit must substantially comply with building and housing code standards that materially affect tenants' health and safety. The basic minimum requirements for a rental unit to be habitable are available in the Dealing With Problems section.
Introducing water vapor into the building that can cause mold and the build-up of dryer lint are both health and safety concerns. I highly doubt these installed items substantially comply with code.
In most locations through-out the US, the law is more on the side of the tenant. But if you choose to invoke them, your landlord will not be on yours anymore.