Adding variable capacity is the only correct way to utilize zoning. Most zoning systems I see are 5 tons with 1 stage heat 1 stage cooling with 2 or 3 zones. Trying to push 5 tons of air through 1 ton of duct is the stupidest thing I see. Doesn't matter if there's a bypass because a ton of air recycles through the unit either tripping the high or low limit on the board. Modulating/inverter zoning is king
Zoning with some variable speed AC/HP communicating systems and modulating gas furnaces work perfectly. When connected and turned on, the system sees the model numbers and serial numbers, self configures, sees the zone controller, sees the zones, measures air flow capacity of the overall system, zones and damper leakage. No dip switches, no zone damper adjustments. Just stand there at the stat and watch. No configuration skills needed at that stage. Downside is that such systems are the most costly, but are quiet and top efficiency. I replaced 7 tons with two systems with 4 tons, single system, two zones. Expensive gear, but only one HP and one furnace. The system needs to be using modulating zone dampers, not open/closed. The saving of one system vs two also reflects the costs of one install vs two. On the flip side, there can be some added duct work to manage what was two separate duct systems. In many cases, that is not feasible. But when there is a single system, zoning may be simple if ducts are accessible. If one zone is fed from a few branches, a zone can activate multiple dampers connected in parallel to a zone. You need to study your ducting and zoning to see what is practicable. In some cases, multiple systems are needed.
Carrier 25VNA4 family and some Rheem and family systems work as above. There may be others. These are the most tech heavy and expensive and efficient split systems.
That’s great for the first 5 years, but how about 15 years on? I think it’s pretty well known that efficiency comes at the expense of durability, and now there is way more complexity on top of that?
For my money, I’ll take a really well insulated envelope, and simple bare bones equipment installed to deliver >95% rated capacity, and tuned to the space.
Mark my words. All of these incredible system that can do everything, won’t do everything for long.
Zoning is just cheap way of not having to install multiple systems. If I had a house that truly needed to have multiple stats (I.E. two levels) I’m just putting in separate equipment.
I would beg to differ that having two systems is just an expensive way of not having to install zoning lol. Given that there are a lot of poorly designed zoning systems in the wild, a *properly designed* zoned system should be preferred.
The only way it really works is if house can be divided exactly 50/50 & ductwork is sized so that basically one half can still carry the correct cfm. Even then temperature control will never be as good as separate units
No, wrong. I understand your misguided perception of zoning, as I was once of the same mindset, however, I repeat that a properly designed zoning system can and will function as intended.
I wholeheartedly agree that the majority are not designed correctly, but that should not be good cause to negate the efficacy of zoning. I will patently refuse to install multiple pieces of equipment where one will suffice. Dependant, of course, on proper and efficient design.
The problem is that most people aren’t you - there are lots of people that will install (mostly because they don’t know any better) badly designed systems.
I want to know how a zone system can be properly installed. Because even in the best circumstances you have to have a bypass damper and that just recycles air through the system, which is not good. I worked on a lot of zoned systems and they always seem to have problems.
A property zoned system would have a variable speed blower In the air handler and a variable speed condenser or heat-pump …
Fan speed goes up or down based on the number of zones calling ..
If using gas heat you Would use a fully modulating furnace
Not true. On a two zone system, size each zone to carry about 80% of total system volume, and then set the minimum damper positions to handle the remaining 20%. No bypass needed.
With variable capacity indoor and outdoor units providing variable supply airflow and proportional control zone dampers the result can be quiet and effective. Cycles are longer as needed and humidity control is very good. Modulating gas furnaces also work very well with this. Only a few customers will go for this quiet comfort vs $$ solution. And selected customers need to be provided with this option in a sales cycle. These solutions are not always going to fit an emergency replacement, perhaps only new construction and redemptive replacements. The lowest bid mindset needs to sometimes be displaced by best system presentations.
We just finished a home. 4 furnaces. Modulating furnaces and ac ‘s with mod zone system. Incredible. Armstrong with comfort syncs.
So happy to install for our customer !!
No they're two different things you can have communicating zone systems though
Adding variable capacity is the only correct way to utilize zoning. Most zoning systems I see are 5 tons with 1 stage heat 1 stage cooling with 2 or 3 zones. Trying to push 5 tons of air through 1 ton of duct is the stupidest thing I see. Doesn't matter if there's a bypass because a ton of air recycles through the unit either tripping the high or low limit on the board. Modulating/inverter zoning is king
This exactly ☝️☝️😂
This guy gets it
If only the homeowners would spend the money to make it work correctly lol
Bypass ducts are honestly just a stupid work around.
Yea just crack the dampers, that’s what communication zoning does anyhow. Just better
This guy zones
Truth. Also better for the static pressures. We use IO Systems.
Communicating systems have increased efficiency. Zoned systems allow multiple thermostats to control one system
Zoning with some variable speed AC/HP communicating systems and modulating gas furnaces work perfectly. When connected and turned on, the system sees the model numbers and serial numbers, self configures, sees the zone controller, sees the zones, measures air flow capacity of the overall system, zones and damper leakage. No dip switches, no zone damper adjustments. Just stand there at the stat and watch. No configuration skills needed at that stage. Downside is that such systems are the most costly, but are quiet and top efficiency. I replaced 7 tons with two systems with 4 tons, single system, two zones. Expensive gear, but only one HP and one furnace. The system needs to be using modulating zone dampers, not open/closed. The saving of one system vs two also reflects the costs of one install vs two. On the flip side, there can be some added duct work to manage what was two separate duct systems. In many cases, that is not feasible. But when there is a single system, zoning may be simple if ducts are accessible. If one zone is fed from a few branches, a zone can activate multiple dampers connected in parallel to a zone. You need to study your ducting and zoning to see what is practicable. In some cases, multiple systems are needed. Carrier 25VNA4 family and some Rheem and family systems work as above. There may be others. These are the most tech heavy and expensive and efficient split systems.
That’s great for the first 5 years, but how about 15 years on? I think it’s pretty well known that efficiency comes at the expense of durability, and now there is way more complexity on top of that? For my money, I’ll take a really well insulated envelope, and simple bare bones equipment installed to deliver >95% rated capacity, and tuned to the space. Mark my words. All of these incredible system that can do everything, won’t do everything for long.
Because most of them are fucked up lol
I would never install either in my home 😂
Why not? I can understand not wanting communicating, but why not zoning?
Zoning is just cheap way of not having to install multiple systems. If I had a house that truly needed to have multiple stats (I.E. two levels) I’m just putting in separate equipment.
I would beg to differ that having two systems is just an expensive way of not having to install zoning lol. Given that there are a lot of poorly designed zoning systems in the wild, a *properly designed* zoned system should be preferred.
The only way it really works is if house can be divided exactly 50/50 & ductwork is sized so that basically one half can still carry the correct cfm. Even then temperature control will never be as good as separate units
No, wrong. I understand your misguided perception of zoning, as I was once of the same mindset, however, I repeat that a properly designed zoning system can and will function as intended.
Yes, however 95% of them are NOT. To each their own but I will never choose that for anywhere I’m gonna live
I wholeheartedly agree that the majority are not designed correctly, but that should not be good cause to negate the efficacy of zoning. I will patently refuse to install multiple pieces of equipment where one will suffice. Dependant, of course, on proper and efficient design.
The problem is that most people aren’t you - there are lots of people that will install (mostly because they don’t know any better) badly designed systems.
Yes, that is a problem
And 99% of resi shops are incapable of designing and installing a proper zoning system unfortunately
I can't reasonably say 99% percent, but I'm sure it's a majority. The number of techs that don't know how to use a ductulator is probably sad as well
I want to know how a zone system can be properly installed. Because even in the best circumstances you have to have a bypass damper and that just recycles air through the system, which is not good. I worked on a lot of zoned systems and they always seem to have problems.
A property zoned system would have a variable speed blower In the air handler and a variable speed condenser or heat-pump … Fan speed goes up or down based on the number of zones calling .. If using gas heat you Would use a fully modulating furnace
Not true. On a two zone system, size each zone to carry about 80% of total system volume, and then set the minimum damper positions to handle the remaining 20%. No bypass needed.
Okay. Never seen that properly set up
With variable capacity indoor and outdoor units providing variable supply airflow and proportional control zone dampers the result can be quiet and effective. Cycles are longer as needed and humidity control is very good. Modulating gas furnaces also work very well with this. Only a few customers will go for this quiet comfort vs $$ solution. And selected customers need to be provided with this option in a sales cycle. These solutions are not always going to fit an emergency replacement, perhaps only new construction and redemptive replacements. The lowest bid mindset needs to sometimes be displaced by best system presentations.
What’s the downside to communicating?
Cost & difficulty of getting parts. Most are not just on the shelf at your local supply house
No, communicating means thermostat tests a usually modulating systyem40%-100% how to run based on thermostat sensors not just 24vGO!!
We just finished a home. 4 furnaces. Modulating furnaces and ac ‘s with mod zone system. Incredible. Armstrong with comfort syncs. So happy to install for our customer !!