Question on single unit central air/Heating system with multi zones
#1
11-21-18, 05:13 PM
Question on single unit central air/Heating system with multi zones
I like to know more about multi zone single unit Central air /Heating system. Can some one suggest a book, or point me to an article somewhere so that I can read and learn all the details. Thanks.
#2
11-21-18, 08:19 PM
Forum Topic Moderator
Not sure that I can point you to a book but I can give you a few points to consider.
Most motorized zone damper systems are only 2 position. This can become an issue if the Leaving air temperature sensor detects that the air is too hot or too cold and locks out your equipment.
Single stage heating and cooling doesn’t work as well with zone systems as two stage equipment.
An Inverter compressor can work even better than a 2 stage with zoned systems.
“Communicating zoned systems” will often work much better with equipment than third party zone systems.
In the 28 years that I have been in this field I am the most impressed with Carrier’s zone systems since they have the ability to modulate some closed dampers before ever causing a LAT sensor lockout.
While Honeywell has a very good 3 zone system, it would not be able to modulate an inverter 5 ton unit down to only 1 ton if but a single zone that only required 20 percent of capacity had a demand. Again a Carrier or a Lennox could do this but only if the equipment matched the zone system.
Most motorized zone damper systems are only 2 position. This can become an issue if the Leaving air temperature sensor detects that the air is too hot or too cold and locks out your equipment.
Single stage heating and cooling doesn’t work as well with zone systems as two stage equipment.
An Inverter compressor can work even better than a 2 stage with zoned systems.
“Communicating zoned systems” will often work much better with equipment than third party zone systems.
In the 28 years that I have been in this field I am the most impressed with Carrier’s zone systems since they have the ability to modulate some closed dampers before ever causing a LAT sensor lockout.
While Honeywell has a very good 3 zone system, it would not be able to modulate an inverter 5 ton unit down to only 1 ton if but a single zone that only required 20 percent of capacity had a demand. Again a Carrier or a Lennox could do this but only if the equipment matched the zone system.
#3
11-23-18, 01:18 AM
Thank you for the information, Here is what I really need to know for now. I have worked on the single zone AC for many years (retired 10 years ago), never worked on multi-zone systems. Last month I bought a 2 year old house, it has Carrier 2 zone AC. Cool side AC works fine, but when I switch to Heat, Zone 1 burner starts, but no fan (with swtich in AUTO position), so the burner turned off itself in about 3 minutes. Zone 2 does not do anything, no burner, no fan. But when I turned switch to FAN ON, the fan works on both zones. Not sure if multi-zone unit works same as the single zone system, is the fan controlled by G wire ? and Heat is controlled by W wire ? I checked the control board, all wires seems connected fine, 2 sets of T-stat wires in, 2 sets of wires ( 3 each) go out to 2 dempers. there are 2 sensor wires go out to somewhere (not sure what the sensors for). The immediately question I have is, how do I turn the fan on (switch in AUTO position) in ZONE 1 when the burner is on ? Thanks.
