To zone or not to zone?
Posted a detailed description of situation before but was likely too long & confusing.
Anyway, Well built, insulated and efficient house in central Texas has a first floor of 2740 sq ft. About 600 sq ft has been very well cooled by an old '86 Trane 1 ton HP and it's kaput. The remaining 2140 sq ft is very well cooled by old '85 Trane 3 ton HP, cooling very well but has issues and it needs to come out too. So 4 tons cools the house very well, we usually keep it set at 74-76. With the small AC out and a fan blowing cool air over there it's still only 78 degress on the small side so this is a good house.
I've decided to replace both units with one 4 ton Infinity HP 25HNA6, of course with matching AH and also Air Purifier. The duct work tie in is no big deal and of course the system will still have an air return on each side.
The question is; is there a real benefit to the additional cost to go with a true 2 zone - the 2 dampers, control board and the second sensor? It's an expensive option. I know people love it, the comfort aspect, but it is truly worth it as a ROI?
Zoning is more for comfort than ROI.
Any ROI would come from setback temps in seldom used zons.If I went with zoning ,I'd go 4 zones ,not that much more ,unless the extr ductwork is costly,and provides more comfort and increases the possible use of setbacks for some ROI.
We really like our zoning systems,going to change the older one to Infinity this fall/winter when it's slow,work wise.
Having two stages really helps with a zoning system.
Thx Dash, yeah it is more costly going up to 3-4 zones from 2. My Tech recommened 2 zones as an option, for comfort and just slightly better efficiency, but not for an real increase in ROI. He said if not true 2 zone than leave the control board and dampers out of it. House doesn't really need it so it's not neceassy to spend the money and that we'd be very pleased with the Infinity 4 ton managing the whole 2740 ft down on it's own.
As it's 4 ton I may go with the scroll compressor model instead of the reciprocating as even the maker (Bristol?) of this recip comp says scroll is more efficient at 3.5 tons and above. Wife and I are very excited about the Air Purifier, allergies are vicious here, and money not spent on zone stuff can go to full 10yr warranty.