In that case why aren't you installing a heat pump?
Which would be much more economical to operate than a gas fired furnace.
It isn't the condition of the ductwork which concerns me - it is the physical size of the ductwork.
If you increase the cooling capacity - you Will have to also increase the air flow volume a like percentage. How will 50% MORE air get through the original sized air ducts properly?
Let me answer for you - it won't.
Cutting a larger inlet hole is just a tiny bit of it - the entire duct system needs to be larger. Please ask your contractors how they propose to accomplish this feat.
Originally Posted by Ryguymedia
Thank you for the input!
We are replacing the furnace because it is what blows the A/C and the piece that has quit on us. We are fortunate enough to live in San Diego and the winters are very mild so heating isnt a huge issue. With that, over the past 15-20 years, the area I live in has gotten hotter and hotter in the summer and we tend to have over 90's a good portion of the year with many weeks over 100 degrees.
The original duct work as far as I have been told by all the contractors is in great condition! One proposal by a contractor wanting to go from the current 2 ton to 3 ton put in the proposal that the hole in which the air enters into the duct work, i think he said intake box, needs to be changed from a 12" diameter hole to a 16" hole to accomidate the larger amount of air flow. Another contractor also wants to go up to 3 ton but did not mention this as something that needs to be done - Have you found that a larger intake box is needed for a 3ton vs. a 2 ton?
The conventional view serves to protect us from the painful job of thinking.