This is my first post here...let's hope it comes out right and I don't violate any of the rules....I'm want to Zone my home. The temperature swing around the house is very large.
I live in Central New Jersey.
2800 sq/ft + unfinished basement (no open ducts).
2 x 3-ton HVAC (Luxaire 10 SEER) - 1 for each floor.
Right now I'm focusing on my upstairs since it has all enclosed rooms, while my downstairs is more open....my goal here is to increase comfort, AND save money. We have unused rooms during the day...and my office is unused at night.
I was thinking of setting up 7-zones (1 for each room).
1) I counted 11 - 5" round ducts...that comes out to 660 CFM. A 3-ton needs 1200. There are 3 fan settings on the blower.
a) Am I destined to a frosted evaporator on the low setting (assuming it's slow enough for the ducts)? OR Not enough flow available for the high setting?
b) If we ignore zoning for a minute...what would having a dump achieve?
c) If we put zoning into the picture...will the dump essentially offset any savings from zoning? I mean...if one zone makes the request...doesn't that mean that 120 CFM (assume 2 ducts) will cause the whole system to run with most of the air being dumped back?
2) Retrozone.com recommended the EWC 7000. I was also reading about the Honeywell TZ-4 (+ TAZ-4 expansion). My understanding is that both have temperature sensors to control the vent temperature.
a) I'm assuming multi-stage cooling/heating means the compressor/burner runs at different speeds. I'm assuming I have single stage...does this mean that I shouldn't use the multi-stage feature to control the fan speed?
b) If one zone makes a cooling call, the system turns on, and shuts off all other dampers except 2 for the calling zone. Much of the air will be cycled by the dump. Won't the temperature sensor then cause the AC to short cycle (aka run 4 minutes -> fan goes for 8 -> AC turns back on for 4 minute)?
c) Are there any controllers that wait for a certain number of zones making a cooling call before turning on? I'm thinking it would be useful because then I would reduce the short cycle...no?
3) Based on all the numbers...6-tons seems too big for my place. Is that the case? If so...what are my options, and why did they oversize it?
4) Would it make sense to run the entire house with 1 x 3-ton system by joining the ducts, and adding more zones? Would I need to do this for the winter as well?
5) Do all these CFM issues and sizing affect the heat cycle?
I hope these questions all make sense and paint a reasonable picture. If any folks of you are in NJ, feel free to contact me personally and send me a quote.