HVAC - Another Messed-Up Zone System

No lie. I get one of these types of calls per week, on average. It harshes my gig. I keep telling these guys to CALL me if they're uncertain or have questions. They know my reputation as an installer and a service tech. I can walk a dude through one of these systems (I've done it many times) over the phone. I've installed and fixed hundreds of'em. I don't understand the 'pride' thing. If you don't know something... you should ASK. I'd be willing to bet that the best service technicians on any team are the ones that asked the most questions.

I asked a LOT of questions when I was a kid. I still do. I'm the most annoying member of an audience at seminars.

Category:

Education

Tags:

• HVAC
• Hack
• Zone
• System
• Bypass
• Damper
• Install

[eggman9713]

Zone systems. Also know to us commercial HVAC design engineers as VVT systems. They are fine for some applications, but I rarely recommend them. They are very finnicky and often lead to more problems than benefits. Residential, they work okay, but I prefer the nicer systems with variable speed blowers and multi-stage condensers, and electronically operated bypass dampers.

[PutSome5tankOnIt]

The systems I work on are not truly 'variable volume'. They are very low tech and economical (read: cheap). Most homeowners want the best technology and performance but are rarely motivated to scribble out a check with an extra digit to the left of the decimal point. Chicks (aka, The Cheapest Creatures on the Face of This Earth) are especially reluctant to dip into their shopping spree funds and shoe allowances to pay for a top-notch HVAC system.

[srtwq09]

lol ''how did that get up there to put that thing up jeez'' just funny how you said it randomly

[PutSome5tankOnIt]

I guess some portions of my video commentary qualify as "thinking out loud". As an installer, I really wonder what the guy was thinking as he was installing the system that I was troubleshooting.

[BGreenHVAC]

@fhtn020273 It seems very rare to actually have a "As Built" schematic.  I have never seen one outside of commercial work. I like that you perform this task.

[KingRhaul]

@californiaisgarbage thanks for the info,i've always rated trane above lennox so guess i've been wrong..i still hate messing with lennox and thier propietary crap but their technology is exactly what i'd need...thought i'd find it in a trane...thanks

[KingRhaul]

@californiaisgarbage i see what you mean, i was think a 3 stage unit which would deliver 40% at first stage, 65% at 2nd and 100% at 3rd stage..so when one zone calls stage one comes on and i'd need the bypass damper,if another zone calls, stage one would still take care of both with no bypass then stage 2 would come in when 3 or 4 zone call and stage 3 when the 5th and 6th zone calls but you just made me realize one thing,even if i manage to balance my cfm's i cant balance mt BTU's properly

[californiaisgarbage]

@KingRhaul running 100k btu split into 6 zones i dont think is possible. even at half capacity, 50% (if that is possible with the equipment )thats looking for around 1000cfm for the smallest zone to keep from cooking your unit, or icing up in cooling. running that on a small zone, say 3 or 4 registers is going to sound like a jet. so there will be a ton of bypass. Your unit temps will be sky high, or frozen solid depending on heat/cool. im thinking two, 2 1/2 ton sys? or some other combination

[californiaisgarbage]

@KingRhaul cant post! Anyway the Lennox setup is the only true zone system that i know of. you can zone a house to run at full capacity with all zones. and as little as a small room and everything in between. you can setup your air speed and keep temp settings for each zone. I have put in hundreds of these without need for any bypass b.s I dont know of any other equipment that has that capability. Check your cfm and btu for each stage of your Trane. Lennox is fully adjustable 4 zone

[KingRhaul]

@californiaisgarbage the unit will be a 5 ton,100k btu,i really dont wanna use lennox neither the homeowner,i'm thinking trane.I know i'll need more than one board, the one thing i wanna find a good solution for is what'll happen when only one zone is calling? for some reason he wants to make 6 zones out of this place,the best idea i got is a 3 stage unit, up to 2 zones per stage and a lil' bypass damper for when one zone is calling.wondering is there's technology out there for a better way

[californiaisgarbage]

@KingRhaul depending on your total cfm and btu you may be able to use one system. or maybe have two small systems. A lennox variable speed A/H or furnace is what the harmony 3 is used with. You can only have 4 zones on this board. so you would need another unit with 2 zones to get the 6 you need. sounds like your chopping the building into a bunch of zones. may be better off with a couple mini splits and eliminating all the ductwork

[KingRhaul]

@californiaisgarbage really? that sounds like what i need,i got a job line up which is a huge 3 story house and the homeowner wants every half a floor to be his own zone since every floor is so big so altogether i'll have 6 zones... i'm wondering if residential hvac has the technology to handle that one without any bypass damper

[californiaisgarbage]

@eldoradoboy every try the harmony 3 with the air speed settings on it? you can set your cfm for each individual zone. Makes it alot easier even if the system was designed wrong.

[californiaisgarbage]

that discharge temp sensor is probably out because the unit goes outside temp with that shitty bypass wide open all the time. you should beat the installer with that counter weight.