.- Plug in air fresheners. 

Less competition, rarified air.  

This allows you to re-mix the hot air that raises to the ceiling and likely let's you lower the setting on the heater somewhat. 

Forced air, unfinished basement, hardwood floor types.

Here is the cheapest I've seen them lately ($330):http://www.globalindustrial.com/p/hvac/air-conditi...It is 240V and requires 12/2 wire and double pole 20 amp breaker but Lowes has one that puts out less heat for $435-600 and uses 120V.Globalindustrial also sells $400 and $500 window units that both put out 16k btu of heat and require 10/2 wire and double pole 30 amp breaker.

We also installed a forced air heating/cooling system.  

I would not say its close to an airport because that would convey it might get noisy from all that air traffic.And, I would also list a way for applicants to contact you through your email or text and not just by phone. 

Asbestos containing material is not generally considered to be harmful unless it is releasing dust or fibers into the air where they can be inhaled or ingested.

Hey @Aaron Britt my name is Tyler and I'm active duty Air Force.

I want my tenants to be proud of their home, and since I plan to hold these properties long term, things like installing forced air, tankless water heaters, etc, are important to me.