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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.
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.
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.
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.
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.
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?
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.
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.
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.
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).
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.
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?
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