The floors were extremely unleveled and the new flooring was already coming apart, in one unit a previous landlord spray textured over every surface of the property including the thermostat/door knobs/trim, in both units the kitchen and bathrooms were falling apart and barely above usable condition, the staircase in one unit was obviously illegal it was so steep, and the walls/ceilings in both units were a mixture of poorly cobbled together panels, cracked lathe & plaster, suspended ceilings that should have been replaced a decade ago, and entire surfaces made from something I couldn't determine.  

(**THIS IS ONLY FOR VERY EXPERIENCED BUYERS)  When you do your 2nd showing on a property you really like, schedule to have a contractor or retired inspector or builder come with you to identify any of the super major items that would cost a fortune to fix and do a mini inspection (IOW, test water pressures, run dishwashers, get outlet tester, turn thermostat up or down to check appliances are working if possible, etc.  

Wifi thermostats are hard wired to the HVAC controls.

Maybe you should consider one of the thermostats that you can monitor via an app on your phone or at least have a programmable one installed so you know its getting turned down when nobody is at the property.

Hello,I recently closed on a triplex and the apartments feels very chilly in winter weather proofing with a plastic cover sealing the windows  mitigated the issue little bit but I would like to get to the root of cause since even when thermostat is set at 80 it feels chilly,especially my lower two units are very cold despite a centralized ac system.Unfortunately I couldn't catch this during inspections since it was warmer weather around that time.I am now dealing with higher utility bills who are some professionals that I can get in touch with for solid weather proofing ?

If the furnaces already have thermostats then they will control the AC as well.Typically the condenser just sits outside on a slab.  

The thermostat being set low could be an indication that the heat was not on.  

With 10% down my payment would be around 1500.00This house has a Goodman ac 14 ser and 1 thermostat situated in upper floor to cool both floors.

That thermostat doesn't set itself. 

I just checked out the new Nest thermostat from lowes.