Is it worth it to install central A/C in rental properties ?

[Sviatoslav Gulko]

Hi everybody! 

Just bought first rental property. Now budgeting and planning rehab for that house. It's an old row/townhouse in B class neighborhood and it has duct for heating system so I have an option to add central A/C to existing heating system. Already had couple A/C contractors and estimated price $3500-4000. Not sure if I need to do that. Will central A/C increasing value of the property?  Any other suggestion on that?

And one more question. Can anyone recommend a good and not expensive Windows company in Philly area(need to replace 8 windows) 

Thanks!!!