@Peeyush Bhatnagar Are you referring to ASU in Tempe or the University of Arizona in Tucson?

It's going to take close to a decade for them to waste 15,000 assuming your managing it with temp settings and no open windows in the Winter, etc.I'm guessing since you are anticipating these upgrades that you are paying a price that justifies them. 

They’re a little more spendy, but they’ll operate at 100% efficiency down to 5 degrees ambient outdoor temp.

Hey @Isabella Donadio, here's my experience from being a landlord for the past 14 years1) I primarily focus on Tempe and the areas around Arizona State University (see #2 for reasoning). 2) The properties rent almost immediately and are never vacant for more than a week.

Slim Mitsubishi air unit which is a lot less than central air and can solve their problem for the few summer months that the temps will be uncomfortable.

These are wifi so you can monitor temp setting, actual temp and humidity.

It's locked and guests can only adjust the temp in the range I set on it. 

Given 50 degree temp from the street(located in Charlotte, NC), that would mean they may have to shower in 70 degree water if the washing machine is also being used. 

There was a 2004 tax case on it Bailey "Because the average length of stay for the Inn on Alisal Road was less than eight days, the court held that Temp.

Total repairs came to about $1500 for a temp fix and a $12k quote for the long term.