I lived in rentals for a long time before I started building our own house; As a renter, I was keener than I was when I lived with our parents.
My experience with heating & cooling was never pleasant in all the 3 rentals I stayed in, but the first house I lived in had a faulty central gas furnace, the hour house lacked regular maintenance, and when I moved to the last house before I moved into mine, the ductwork ended up being in a awful state.
The struggle the landlord had made myself and others think about installing a radiant furnace in our house. Many times the landlords had to engage more than one a/c workman to carry out the Heating, Ventilation, & A/C service or some repair work. And being old systems, the seer ratings were well below the recommended 13. When I hired our Heating, Ventilation, & A/C corporation, our main focus was to have quality Heating, Ventilation, & A/C ductless units in the house & avoid ductwork related expenses, but so she ensured that all our Heating, Ventilation, & A/C device was new & energy-efficient. That would include any portable space furnace appliance I buy. Shopping for new Heating, Ventilation, & A/C device is easier now than before. A great Heating, Ventilation, & A/C corporation salesman will enlighten you on the best appliances for your premises, & also offer an air conditioner service plan, with every air conditioning installation, but i lived in areas that had extreme weather variations however I realized I am more tolerant of colder weather than hot seasons. So I have invested in a reliable & efficient cooling plan but generally, it pays to have regular air quality systems in the house.