Will ZC help me

[erikbgt05]

So quick recap of the situation, I have a Trane XE80 in my attic 3ton cooling unit. Live in a 2 story house 1750 sq foot in GA, so winters can be cold, and summers very hot. 2 returns upstairs and downstairs. The thermostat is in the middle of the stair well between the 2 returns.

My dad was able to tell me that I could adjust the blower speed so I set now heat to high and cool to med-high (reversed what it was). However, he disagreed against doing a zone control. I figured if I created two zones upstairs / downstairs with thermostats it would greatly help the comfort of the house rather than upstairs an inferno while downstairs is cold (at least right now). His point was that really a HVAC "sucks" the air from the registers to the returns. And by zoning it I would greatly hurt my efficiency / air flow.

What are your thoughts? I planned on using HZ311k (3 zoner) and then put in 5 dampers (1 for downstairs, 3 for upstairs, 1 for the master) to have 3 zones. I appreciate your advice or suggestions!

--Erik

[catmanacman]

zone controled units are great if properly installed and set up

[bmathews]

Are you planning on attempting this yourself? Or are you hiring somebody to professionally engineer the thing? No offense, if you are planning on this being a DIY project, it isn't gonna work. Hell, half the hvac companies that attempt it would screw it up. So be very careful who you hire. That's a lot of zones, 3 of them being small zones, tricky to do. Go Carrier Infinity zoning and equipment, it idiot proofs the process to a point.

[erikbgt05]

Are you planning on attempting this yourself? Or are you hiring somebody to professionally engineer the thing? No offense, if you are planning on this being a DIY project, it isn't gonna work. Hell, half the hvac companies that attempt it would screw it up. So be very careful who you hire. That's a lot of zones, 3 of them being small zones, tricky to do. Go Carrier Infinity zoning and equipment, it idiot proofs the process to a point.

It would be DIY, however, I'm thinking that I would have to redo my plenum to really do it correctly also and build in a static pressure return / change it to 3 trunks rather than the setup it is now. How is the Infinity any different than the Honeywell? And the screw it up is why I'd rather do it myself, my dad was a GC for 30yrs+ and I tend to trust his opinion instead of some snake oil salesman who can sell me the world and a nice pricetag. The ZC setup I spec'ed would only cost around $$$ bucks and a few hours of time, which I think was worth a shot.


Pricing isn't allowed

[comfortdoc]

?..... The ZC setup I spec'ed would only cost around $$$ bucks and a few hours of time, which I think was worth a shot.

If that is what you think it will take, it will never work. As already stated, retrofitting a zone system is difficult for experienced contractors. It will not work if you do not understand the thermodynamic principals of system design. And the statement above shows you do not.

[Brent Ridley]

It would be DIY, however, I'm thinking that I would have to redo my plenum to really do it correctly also and build in a static pressure return / change it to 3 trunks rather than the setup it is now. How is the Infinity any different than the Honeywell? And the screw it up is why I'd rather do it myself, my dad was a GC for 30yrs+ and I tend to trust his opinion instead of some snake oil salesman who can sell me the world and a nice pricetag. The ZC setup I spec'ed would only cost around $$$ bucks and a few hours of time, which I think was worth a shot.

DIY is a very bad idea with this setup.

It's not as simple as adding in a few dampers. You need to make sure every zone has the correct CFM with as minimal static pressure as possible.

This will take performing a full manual D duct design.

I really suggest hiring a professional for this.

Just remember, improper airflow can lead to compressor failure along with a whole slew of other issues.

[erikbgt05]

Well to those who didn't ask I'm actually almost a PE, so I do have some pretty in depth thermodynamics understanding (thanks for assuming!), but I was going to let my MPE friend actually help spec out the airflow since that's more on his side of the house what he does (commercial and he has that manual D tool). I'm trying to do my research first before getting into it, since again regardless my guesstimates with initial figures it will be around $$$ bucks of parts and just time using modulating dampers to control the CFM / pressure based on the numbers we come up with.


Pricing isn't allowed

[kangaroogod]

.

[energy_rater_La]

...? that's my line!

OP this is very much a no diy site,
even for actually almost PE's.

bmatthew's is 100% correct, zoinig is
for trained, experienced hvac pros.

best of luck.