Indoor air troubles due to shared vents

My lovely lady friend plus I were living with her parents for 6months. I was working at the factory on the third watch shift plus my lady friend was at home caring for our more than one children. All of us had a decent apartment before the people I was with and I had to move in the home with the parents, however the place was filled with rodents plus roaches plus the people I was with and I had to transport out quickly. Things were going well until my lady got into a big argument with her parents plus they told us that the people I was with and I had to move out stuff out immediately. All of us had to find a place suddenly plus the only vacant apartment was inside a cramped building with several other tenants. It’s cheap, however there are some nagging troubles. For instance, the people I was with and I all share the same water heater. If pretty much every person showers at the same time, the last person does not have a hot shower. All of us also have to share the same HVAC component plus the same air vents plus ducting system. This has been a growing concern since the first afternoon the people I was with and I moved to the modern location. My lady friend plus I do not have any pets because the people I was with and I have intense dog irritations. One of our neighbors has cats plus the people I was with and I always sneeze a lot. The pet dander travels through the HVAC system via the ductwork plus now the people I was with and I are exposed to the same germs plus allergens. All of us have to take Claritin D everyday. All of us signed a 6month lease, so we’re stuck with the shared ventilation system for a little while. At least the apartment building is right across the street from a great park with basketball hoops, tennis courts, a playground, plus a pond with ducks plus fish.

Ductless heat pump