[torq_shep]

I found a contractor that will install the unit I am looking at but he said 2 things that I have questions about.

-First he said with a 2-stage communicating A/C unit (In this case Goodman GSXC16 w/ComfortNet) that I have to use the goodman thermostat. I believe that the unit can still be wired traditionally into my Honeywell HZ322 (2H/2C) controlled by 3 seperate single stage thermostats. Is this correct? From my understanding ComfortNet does not support zoning.

-Second, he said that even though the coil case is 24.5" and the furnace is 24.5" that they would be "incompatible" and that I would have to change the furnace out as well to go with the 2-stage condenser. Is this accurate?

Thanks Again!

 

[Bazooka Joe]

Briefly looked at the AHRI numbers for the GSXC16 ( no mention of what tonnage and indoor cased coil number your using, ) shows with your existing furnace at best your getting between 14-15 SEER. If they quoted a CAUF coil they would need to install a OEM TXV to even get to the 14-15 SEER. If you wanted a up to 17 SEER unit, yes you would need to get the matching Goodman Furnace. What is the complete model numbers of ID and OD unit.

Ask for the AHRI certified reference number from this Company for the system they are proposing to prove a matched system then check here.

https://www.ahridirectory.org/


The rest of your questions ( 1st question ) Im not sure what to tell you.

Any mention from this Contractor about possible rebates?

http://www.dsireusa.org/

 

[samgevas]

Why pay extra for a communicating system if your not going to use that feature?


Sent from my iPhone using Tapatalk

 

[BaldLoonie]

If you are getting 2 stage equipment, I'd get the 432 panel. It will stage based on % of zones calling. That way the installer can set it up so it won't go to high unless all zones are open and can take that much air. Otherwise you'll cycle on discharge air sensor or furnace limit going to high with 1 zone wanting heat.

 

[torq_shep]

Briefly looked at the AHRI numbers for the GSXC16 ( no mention of what tonnage and indoor cased coil number your using, ) shows with your existing furnace at best your getting between 14-15 SEER. If they quoted a CAUF coil they would need to install a OEM TXV to even get to the 14-15 SEER. If you wanted a up to 17 SEER unit, yes you would need to get the matching Goodman Furnace. What is the complete model numbers of ID and OD unit.

Ask for the AHRI certified reference number from this Company for the system they are proposing to prove a matched system then check here.

https://www.ahridirectory.org/


The rest of your questions ( 1st question ) Im not sure what to tell you.

Any mention from this Contractor about possible rebates?

http://www.dsireusa.org/

Joey,

This particular contractor has not quoted me yet, I have just been talking to him about what I want. Trying to get my ducks in a row before having him come out. I know I want 2-stage, from cool-calc manual J I could be as low as 39k BTU cooling and as high as 46k, and I already have mostly new ductwork installed with 3x zones (2x900sq-ft 1x400sq-ft) I cannot find a manufacturer that makes a 3.5 ton 2 stage or I would go with that.

I have an AS Silver 80 5-ton furnace single-stage from 2017 (oversized but functional, has speed taps for the blower, gotta love 1970s construction and lazy contractors that don't bother to resize from original if needed). I spec'd a GSXC160481 4-ton 2-stage and a CAPT4961D4 coil and asked him if he could get me that or something similar.

CPS (San Antonio Power) offers $130 a ton for purchasing 16-seer over 14-seer.

Why pay extra for a communicating system if your not going to use that feature?

Sam,

I cannot find a non-communicating 2-stage condenser.

If you are getting 2 stage equipment, I'd get the 432 panel. It will stage based on % of zones calling. That way the installer can set it up so it won't go to high unless all zones are open and can take that much air. Otherwise you'll cycle on discharge air sensor or furnace limit going to high with 1 zone wanting heat.

I just read over the manuals for the 432 and the 322 and both allow you to set 2nd stage limits on % of zones calling. I currently have a 311 but will get a 322 once I have a lock on a contractor =P

 

[ga-hvac-tech]

Joey,

This particular contractor has not quoted me yet, I have just been talking to him about what I want. Trying to get my ducks in a row before having him come out. I know I want 2-stage, from cool-calc manual J I could be as low as 39k BTU cooling and as high as 46k, and I already have mostly new ductwork installed with 3x zones (2x900sq-ft 1x400sq-ft) I cannot find a manufacturer that makes a 3.5 ton 2 stage or I would go with that.

I have an AS Silver 80 5-ton furnace single-stage from 2017 (oversized but functional, has speed taps for the blower, gotta love 1970s construction and lazy contractors that don't bother to resize from original if needed). I spec'd a GSXC160481 4-ton 2-stage and a CAPT4961D4 coil and asked him if he could get me that or something similar.

CPS (San Antonio Power) offers $130 a ton for purchasing 16-seer over 14-seer.


Sam,

I cannot find a non-communicating 2-stage condenser.



I just read over the manuals for the 432 and the 322 and both allow you to set 2nd stage limits on % of zones calling. I currently have a 311 but will get a 322 once I have a lock on a contractor =P

IMO... your proposed zone system is gonna cause you problems...
The small zone is not gonna work properly... rather cycle the equipment on limits.

You are a candidate for an inverter drive zoning system... however that is something that really needs to be installed by someone that has 'been to school' on the equipment. And the combination of the equipment and the proprietary zone system and someone that knows what they are doing... is gonna be pricy!

OTOH... why not put a mini-split in for the small zone... I am guessing that is either a basement or bonus room.
Then use a 3-T 2 stage for the other 2 zones???

Yeah, a little more $$$... but a system that would work properly (given the limitations and variables of zoning).

 

[Bazooka Joe]

CPS (San Antonio Power) offers $130 a ton for purchasing 16-seer over 14-seer.

How does CPS determine the 16 SEER? Do they go by a AHRI number? If so at best you will get 15 SEER, due to the furnace is not a Goodman. Also I did not see in AHRI directory that the CAPT is matched to the GSXC16048.

Do see the CAPF4961+EER+TXV gives you 15 SEER.

Ask the Installing Contractor for the number when you get to that place.

Ask CPS how they determine the tonnage to 16 SEER, do they just go by what the OD unit is capable of reaching or do they go by the AHRI certified reference number.

Here's an example of what they may require:

https://www.ahridirectory.org/Home/...ad?ReferenceId=sUzbLVC3/aFB9wkj0dGAHzUo9/olKYzIV/Jo3z/NCkZQuBnvbkovtrtY6EWj8H41

 

[torq_shep]

IMO... your proposed zone system is gonna cause you problems...
The small zone is not gonna work properly... rather cycle the equipment on limits.

You are a candidate for an inverter drive zoning system... however that is something that really needs to be installed by someone that has 'been to school' on the equipment. And the combination of the equipment and the proprietary zone system and someone that knows what they are doing... is gonna be pricy!

OTOH... why not put a mini-split in for the small zone... I am guessing that is either a basement or bonus room.
Then use a 3-T 2 stage for the other 2 zones???

Yeah, a little more $$$... but a system that would work properly (given the limitations and variables of zoning).

DOH!!! Why didn't I think of putting a mini-split in the converted garage... That makes much more sense. Brings my Cool-Calc manual J down to 38k so with zoning and re-insulation/air sealing of the upstairs a 3-ton 2 stage should work fine. I will likely go with a cheaper Senville 0.75 ton over the Mitsubishi 0.5 ton in that room as I will not be using it all that often (only when I am running my CNC). When comparing cost of cheap mini-split + 3-ton + 2-zone to a 4-ton + 3-zone It is ~75 more for the mini-split solution.

I may try and get 1 more season out of my old 3.5-ton so that I can log data on it for how long it runs in the 2-zone system. If I am running less than 85% of the time on my hottest days then I can easily downsize to a new 3-ton.

 

[ga-hvac-tech]

DOH!!! Why didn't I think of putting a mini-split in the converted garage... That makes much more sense. Brings my Cool-Calc manual J down to 38k so with zoning and re-insulation/air sealing of the upstairs a 3-ton 2 stage should work fine. I will likely go with a cheaper Senville 0.75 ton over the Mitsubishi 0.5 ton in that room as I will not be using it all that often (only when I am running my CNC). When comparing cost of cheap mini-split + 3-ton + 2-zone to a 4-ton + 3-zone It is ~75 more for the mini-split solution.

I may try and get 1 more season out of my old 3.5-ton so that I can log data on it for how long it runs in the 2-zone system. If I am running less than 85% of the time on my hottest days then I can easily downsize to a new 3-ton.

CNC in the garage huh...
Would that be metal working or wood working???

I have a manual lathe and mill (metal working) in my garage...
I can tell you that you do NOT want the smell of soluable oil in your zone system... in your home...
Grin!

 

[torq_shep]

CNC in the garage huh...
Would that be metal working or wood working???

I have a manual lathe and mill (metal working) in my garage...
I can tell you that you do NOT want the smell of soluable oil in your zone system... in your home...
Grin!

I have crazy level tools... CNC Mill (IH), CNC router (4x8), metal brake, giant air compressor, Miller Tig, Hobart Mig, Hypertherm Plasma, etc etc etc. Once I am done working on the ductwork and getting all of my crap together I may go back to being a pretend fabricator =P

I desperately want a metalworking lathe... BUT I need to have my house in order so that my roommates stick around so I can buy more toys.

Also, I really mega appreciate all of the help y'all have been. I am pretty good with all of the math and calculations stuff but like all engineers I can overthink just about everything. I ended up ordering a Daikin 9000BTU for the workshop! It also massively simplifies the ductwork I need to finish.

So final configuration will likely be:
Honeywell HZ322 zone controller
White and Rodgers programmable thermostats
2x Zones (upstairs/downstairs) ~900 sq/ft each
Daikin 9k BTU mini-split in workshop
Goodman 3-ton GSXC16 w/matching coil and a smaller furnace

 

[ga-hvac-tech]

That should work a LOT better than what you posted at the start of the thread... grin!

Go here:

HobbyMachinist.com

Forum for the guys with a metal working shop at home... or in the barn in the back... or in the shop building in the back that is larger than his home... grin!
IMO... a shop building in the back is a REAL mancave... :cheers:

Anyhow... a great forum for folks that play with metal working.

My lathe is 13x42, built to exacting standards... it is marketed as a gun-smithing lathe (no, I do not do firearms work), it is supposed to hold to 'tenths'... and it does when one sets it up properly! My mill is a Bridgeport J-head clone... neither have any automation... I am the old fashioned guy that likes to twist wheels and watch what I am doing... :angel:
Both have 3PH motors and VFD's, they run on home 240V single phase.

I have a 22x48 tamale wagon full of tooling for the machines... plus a shelf of things like a rotary table, stops, dividing wheel, etc...
Oh, I did not mention... I own an experimental aircraft I built...
Understand why I have the shop... grin!

 

[torq_shep]

That should work a LOT better than what you posted at the start of the thread... grin!

Go here:

HobbyMachinist.com

Forum for the guys with a metal working shop at home... or in the barn in the back... or in the shop building in the back that is larger than his home... grin!
IMO... a shop building in the back is a REAL mancave... :cheers:

Anyhow... a great forum for folks that play with metal working.

My lathe is 13x42, built to exacting standards... it is marketed as a gun-smithing lathe (no, I do not do firearms work), it is supposed to hold to 'tenths'... and it does when one sets it up properly! My mill is a Bridgeport J-head clone... neither have any automation... I am the old fashioned guy that likes to twist wheels and watch what I am doing... :angel:
Both have 3PH motors and VFD's, they run on home 240V single phase.

I have a 22x48 tamale wagon full of tooling for the machines... plus a shelf of things like a rotary table, stops, dividing wheel, etc...
Oh, I did not mention... I own an experimental aircraft I built...
Understand why I have the shop... grin!

I have a 24x24 detached (unfinished = No A/C but I am very heat tolerant) and the 20x22 converted (where the mini-split is going). I am an auto engineer by trade and I never cease to have project cars. I may have a problem owning old broken crap... Like this house =P

Having the tooling to do whatever you want is the best! I hate being the DIY'er here but I like to know anything about everything. Have to put 6 years of hell doing asinine thermodynamics to use somewhere. However, I am a firm believer that experience is often better than theory, that is why I ignore PHd's. So far at least I got the airflow calculations correct to my 2nd story (Design 910CFM, Actual 980CFM).

 

[pecmsg]

For the garage a cheap Mini. All that dust is going to kill it so be prepared to replace at least the indoor section in 5 - 7 1/2 years.

 

[torq_shep]

For the garage a cheap Mini. All that dust is going to kill it so be prepared to replace at least the indoor section in 5 - 7 1/2 years.

I kind of figured. I may end up moving the dusty stuff to the 24x24 and moving all of my low dust stuff into the 20x22. Considering cutting my 4x8 CNC in half, and building 2 seperate tables. One table for plasma and one for router. The router is the one that makes the biggest mess.