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gglaze
03-24-2006, 01:14 PM
Does anyone have experience with the Unico duct system (the small diameter supply duct system)? I'm thinking about trying it on a job and am looking for the pros and cons.

Thanks,

Gene

Finnegan
03-24-2006, 03:17 PM
I have seen them installed. They work fine, but they are expensive. I would recommend the Unico or Spacepack systems only when you need them due to the installation requirements.

andrewt
03-24-2006, 09:54 PM
Godawful expensive...no need to use it unless space dictates.

James Eggert
03-25-2006, 09:04 AM
Actually, I don't agree with the expense issues. I will say though that there are some offered proprietary components that can be changed to something else which along with possible installation savings can make HV competitive. However, it also is not a save-all solution for every project.

I have Unico in my own home. I also use Unico(SpacePak is OK and probably cheaper) when I want a split system of hot water type baseboard and AC in the ICF homes I build. I'm not in love with the hot water coil heating side UNLESS you have either a variable speed blower, or a user adjustable fan speed setting. I'm also not fond of the electric module unless it's main intent is electric backup!

These systems remove about 30% more humidity than conventional systems, and as in any AC system, it needs to run a sufficient amount of time to work well.

gglaze
03-25-2006, 04:40 PM
The cost is why I haven't used it before but am now buiding my own home and am installing a geothermal heat pump. MY HVAC contractor wants to go with the Unico system on the first floor to take advantage of the extra dehumidifcation and proposes two separate systems for this floor (MBR and the rest of the first floor). He also wants to switch to a water to water system and feels the Unico system works better with this. (BTW, he plans to use a traditional duct syetm for the 2nd floor.)

The bottom line is that he's offering to do it at a discount so cost is not the issue...I'm just a little nervous about using something new on my own house.

Thanks,

Gene

Total-Home
03-26-2006, 08:50 AM
We use Unico quite frequently for A/C in older homes and apartments, typically pre WWII buildings where the reduction in ductwork size allows us to install without large soffits. It is a very good system for A/C in our area (Chicago metro) but my HVAC sub does not feel that it can supply enough heat for primary heating in our climate. We typcially see the unico air handler with a Trane condenser.

We have used it as supplemental heat in projects with radiant floor heat where the response time of the radiant does not allow quick heating up, or elimination of heating in the transitional seasons. We get many days in the spring and fall where it can suddenly turn cooler and you need heat, or it quickly warms up and the radiant may overheat the living space.

All in all, it is a good, and not new system.

James Eggert
03-26-2006, 09:31 AM
Gene
I understand the Unico AC for the first floor, why not also as a split system for the second? OK, maybe I'm not understanding how you will set up the second floor, when you say a ducted system. This would be for both heat and AC?

I'm also not understanding how you will use the Unico with a heat pump? Once again, are you using the Unico ducts for heat generated from a heat pump for the first floor???? Or are you using the unico only for AC? The geo systems appear to have really improved from years past, and although the payback may take awhile, they do handle the bulk heating issues. I would review the geo use with the unico, it can be done, but I would question the air speed? How about a little more system explanation?

gburnet
03-26-2006, 09:35 AM
The bottom line is that he's offering to do it at a discount so cost is not the issue...I'm just a little nervous about using something new on my own house.

Thanks,

Gene

This type of system has been around for decades, so I wouldn't worry about being a lab rat for it. It's got a proven track record around here, & many of the houses we work on have this system, or we end up having our HVAC guy install it. It's a good way to get A.C. into an old house or into a house where there's no room for conventional ductwork, & so far I haven't heard any complaints about it, as long as it's properly installed.

Greg

HYUGAVED
03-26-2006, 11:46 AM
We do a lot of our work in old houses. A properly balanced Unico system winds up being out of sight and out of mind when done. That's something to be appreciated even in a new house.

Hausdok
03-27-2006, 10:24 AM
Hi,

Didn't someone complain about noise issues with these a while back? Maybe it was another forum but I seem to recall some discussion about how the HV systems had some 'whistling' issues.

OT - OF!!!

Mike

Total-Home
03-27-2006, 12:07 PM
If they are properly installed they don't whistle.

Steve M
03-27-2006, 03:51 PM
We've had two installed with no whistle. You can hear it run because of the high velocity air but it's not loud or distracting. I have heard of some Unico installations that do make noise. I was told they ducts had been installed incorrectly (sharp bends).

Steve

James Eggert
03-27-2006, 06:51 PM
As far as I'm concerned the installation should be all sound attenuation ducts and don't even use the regular duct they sell. It's not worth the aggravation if you make a bend a little too tight and create some noise.

I did my house this way with all sound duct; some installers use the factory regular ducting and add a 6' piece of the sound duct just at the end of the branch run. I don't recommend this approach, although the factory specifies it this way, but I think it's too lower the duct cost a little. When you take the time to cut sound duct, then use the special coupling to attach them together, the time just isn't worth it.

SolarPowered
03-27-2006, 08:19 PM
I've noted that Unico and SpacePak claim that their systems are "quiet." As I read their promotional literature, I took that to mean that they're quieter than standard low-velocity A/C. From what people are posting here, I take it that that's not really true?

James Eggert
03-27-2006, 08:32 PM
They are not dead quiet, if that's what you mean. However, the background noise is minimal when installed correctly!

SolarPowered
03-27-2006, 08:53 PM
I guess I didn't express well the actual question I have in mind!

What I'd like to know is how a Unico or SpacePak system that is designed and installed with attention to making it quiet compares with a conventional A/C system that is designed and installed with a focus on making it quiet.

gglaze
03-28-2006, 04:09 PM
Gene
I understand the Unico AC for the first floor, why not also as a split system for the second? OK, maybe I'm not understanding how you will set up the second floor, when you say a ducted system. This would be for both heat and AC?

I'm also not understanding how you will use the Unico with a heat pump? Once again, are you using the Unico ducts for heat generated from a heat pump for the first floor???? Or are you using the unico only for AC? The geo systems appear to have really improved from years past, and although the payback may take awhile, they do handle the bulk heating issues. I would review the geo use with the unico, it can be done, but I would question the air speed? How about a little more system explanation?

Jim,
He proposes traditional duct through the attic for the 2nd floor. The entire system will be run off a 5-ton geothermal loop and I will wind up a with a 2.5- ton unit (two zones) to serve the 2nd floor via a traditional duct system.

The original propsal for the 1st floor was similar with a 2.5-ton unit (linked to the geo-thermal system) with two zones.

The proposal now is to use two Unico systems for the first floor only. We would have one system for the master suite and one for the rest of the first floor instead of zones like the 2nd floor. He also proposes switching the entire geo system to water-to-water technology. I'm a litle unclear as to why the switch, but think it has something to do with taking advantage of the ability to utilize the geo system at different capacities as needed, depending on how many of the three separate units are calling at once. He also mentioned that we would get greater dehumidification from the Unico system.

He proposes installing the registers in the floor and although the Unico web site says floor outlets are OK, it seems to indiacte that ceiling installation is the preferred method.

The bottom line is that he tells me that he had concerns about the finished ceiling height for the basement (to be finished at a later date) and about the comfort level in the home. I think he's a little over concerned about this but realize that the Unico system will likely provide more comfort.

If it matters, we build our homes very tight and perform duct leakage and blower door tests (typically by a HERS rater). We also intend to bring in fresh air but feel that it's difficult to justify an ERV or HRV in our climate so we plan to just pipe in a small amount of fresh air directly into the return side with a damper that will close on excessively cold or humid days.

Thanks for your advice.

Gene

NCremodler
02-22-2011, 08:56 AM
I had two unico units installed in a large remodel job in NC. It has been nothing but trouble. Hard to determine if it is install or equipment or both. Factory has been involved but not corrected the issues. The units continually break. One unit was factory replaced 2 years ago and now "non site repairable" I would not use it again in a job.

NCremodler
02-22-2011, 09:09 AM
Used Unico systems in a large home remodel in NC. It has been a disaster from day one. Difficult to tell if it is bad install, poor product or both. Continually breaks down. The chillers were factory replaced 2 years ago and now broken again and non site repairable. I would not use it again.

James Eggert
02-22-2011, 04:38 PM
And yet all of the ones I used, including my own, have performed both well and without requiring repairs??

I did have a difficult time with my repairman finding a freon leak problem, eventually we(he) tracked it down to a compressor problem. Oh, yeah, the mouse that got into the outside unit and chewed up some wiring that fried a capacitor is not able to chew anything else at all!

In this case by repairs I mean the actual Unico equipment. The outdoor stuff is Frigidaire.

NCremodler
03-07-2012, 08:45 PM
In greenville SC there have been 16 unichillers put on one job trying to find 4 that will last longer than 6 months. Similar problem in mars hill, nc. My job has seen the same with chillers having a total breakdown and not able to go from heat to air. Same situation outside raleigh, nc. They are not dependable and not recommend. Unico seems to have a problem that has lasted 6 years.

James Eggert
03-08-2012, 06:36 AM
So you're having issues with the outside heatpumps(chillers?)? In a residential setting I have not had any of those issues, but if there is an equipment problem I also would change to another brand for the outside equipment.

When I did my house in 2000, I did not use Unico outside, only the interior part of the system. Same goes for the other installations I specified it's use.

NCremodler
03-09-2012, 08:52 AM
The airhandlers are ok. The outside Unico unichillers (reverse cycle chillers) are a huge problem. They have total failure in about 6 months. Led to believe it was my one job ... But I have now found 4 jobs with same story. Unico has known this and been working on this problem 6 years. The units lose refrigerant and can not be site repaired. I would not use another Unico chiller.

James Eggert
03-09-2012, 04:13 PM
Under those circumstances I wouldn't either! But sometimes depending on climate the high velocity systems run differently than regular air to air systems.

So is the issue repeated anywhere else in your area with other outside equipment? Only a question but as you get into larger chiller type equipment, that is beyond my expertise!