I have an old a c unit that used to use R refrigerant and I need to replace the condenser unit. Do I have to change it to the same R or can I change it to thes using the new refrigerant without having to change other components on the central A C unit such as the inside blowers, etc?.HomeAdvisor’s Air Conditioning Cost Guide lists price information on installing a new A C unit, as reported by HomeAdvisor customers..Central AC systems come in various sizes, between . tons. The larger the system, the most expensive the coiland installation will tend to be..Heating and air conditioning repair in Boise, ID. Right Now Heating and Air Conditioning offers home cooling and AC repair service..