Either repairs, credits, or price reductions.

A ducted system WILL NOT.The reduction in the electric bill will NOT be anywhere near $100.

From reading your tomb, I'd say you might be a little too involved - might want to take a chill pill and give 'em some space.

I understand there isn't a magic pill you can take to build six pack abs. 

If you want to update the place you could do it at your own expense (considering the good advice from other investors above) and give notice to the tenants of a future rent increase in accordance with your lease agreement and applicable law where the property is located; pay now and charge higher rents on your next lease; allow tenants to pay and deduct the expense from the rent as a reduction in rent payments for the next 4 months or whatever you decide, etc... etc... several ways to structure it. 

I will say that we do still have two properties that are currently on Airbnb, and those two properties in particular we haven't had much of an issue with.Compare that to the nightmare rental we had in Pill Hill (which was the source of probably 2/3 of the horror stories, yet identically furnished), and I think the consensus through this thread is that it's all about location.

If you can keep in mind that this reputation deserves a discount in the price since it involves you taking a greater risk and you do it with ultimate in confidence, you just might get a reduction.

Risk reduction is the primary goal in the prevailing business practices in our industry.

I want to do right by everyone involved but getting sued into buying a house is a unmanageable pill to swallow. 

If a tenant asks for a lease modification because of a loss of job permanent/temp/reduction in hours/reduction in pay.