Whenever the board of county commissioners of any county having a population of less than three thousand (3,000), or any county having a population of more than five thousand four hundred (5,400) and not more than six thousand (6,000) and an assessed tangible valuation of not less than twenty-five million dollars ($25,000,000) and not more than thirty-five million dollars ($35,000,000), owning a county home for the aged, shall have rented, leased or let said home for the aged to any person, corporation or society for the purpose of maintaining and operating said home, all proceeds from any such renting, leasing or letting may be placed in a county home improvement fund. Said funds, when established, shall be used for the purchase of equipment and for the maintenance and repair of, and additions to, said home.