For all you mathematically minded people try our out our helpful links when you upgrade your furnace and air conditioners.
Our Lennox calculator - shows how much money you will save in 5 years. For example: if you have an 8 seer a/c and upgrade to a 13 seer a/c you will save $200. Notice that you can change your province/state-as energy rates are different where you are located.
Compare your furnace efficiencies - Annual natural gas savings calculation.
Check out these SaskEnergy youtube videos: