Thanks in advance for assistance.
I build houses in GA/SC area and have been for the last 18 years. Back in the day we cooled and heated houses just fine without the variable speed compressors, air handlers. It was just the single speed systems and usually had no issues- issues were related to duct runs or defective equipment.
What we did not have back then:
- Impact glass and the sealed window assembly
- Spray foam roof deck
- too many choices on what systems
I recently replaced the systems in my personal house with dual fuel variable speed units. A huge upgrade from the single speed 20 year old systems.
My house was built in the 70's and I added foam to roof deck, but I have single glazed windows. The systems are ok. I got a great deal so no complaints there, but the bottom line is I don't think it has made that much of a difference in the power bill to warrant the significant cost of the systems.
That was just a personal experience with todays systems, my question relates to the houses I build.
The houses are typical open cell foam, batt walls, slabs or crawl with closed cell if crawl. Windows are Marvin impact. Window assembly includes silicone over visqueen at jambs. Flanges are taped over with window wrap and tyvek or 30lb felt over. Wood siding and metal roofs are typical.
Here's a senario:
Bonus room over garage (attached to house via covered roof) approx 500sqft
second story of house is only 500sqft and contains a bedroom/bath
Main area is bedrooms/kitchen/master wing
Ceiling heights vary, but it does have a high vault in family room
-One of the prices I got back was $ and zoned the bonus with the 2nd floor and the main with the downstairs bedroom and put the master on a 2 ton system. Everything variable speed indoor and out.
Going to (5) 14 SEER systems with a ducted mini in the 2 second floor areas saves me about $.
I know there's a lot more than what I have just said, but I'm trying to keep it as short as possible