Hi-V Air Handlers

Big Ed_4

.....if it was not for the extra cost in buying them.

You will need to do a heat gain calulation per house then per room. No dampers are used and you don't want to over size these bad boys.

You need to install 7-8 take offs per ton. Less then that noise levels increase. You don't want to plug in take offs too close in line of each other. The best way to tnstall the supply plenum is in a circle for more even pressure.

I like them you just need to design them right. That's the key.

AZ

Hi-V Air Handlers

I'm getting more and more requests for these hi-velocity air handlers. What has been your guys' experience with them? I've heard some nasty things about the brands hi-velocity and ESP. Are there any other brands out there that people use and like?

joel_19

HI V

We have used Unico for years very reliable put in well over 100, 200? I see alot of them all screwed up because folks don't follow the instructions very well. For instance I asked the supply house if they stocked replacemenet blowers just in case we lost one. " Ohhh sure we sell a few motors every week" Now up untill recently we've never had 1 fail. I suspect others have the attrition rate do to poor ductwork and the motors being overamped. We keep them where they need to be and no problems.

The Steam Whisperer (Formerly Boilerpro)

Of great interest

TAke a look at the ARI efficency rating with the various Manufacturers products. Most High velocity systems show much lower SEER ratings, but one. The ESP Models maintain the standard Seer ratings or get better than the matched air handler. Also they have ECM blowers...so they should use alot less electricity to run the blower and less to cool the blower motor.

I also saw one of the manufacturers is introcuding 2 1/2 inch ducts, instead of just 2 inch, for more airflow and less vents to save on installation costs.


Boilerpro

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tom_49

Unico

We have installed a bunch of Unico. Good product. I would recommend using their "advanced control module". it ramps the blower up and down for quieter operation.BP is right about the seer ratings. They do come in lower and do NOT qualify for any utility rebates in my area. You can even zone the Unico, but you have to vewy,vewy careful. Just follow the directions for duct lay-outs.



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Nikolai

High Velocity Fan-coil

10 years we design and sell Energy Saving Products Hv-V packages to heating contractors. All our packages go with detailed duct/vents layout based on room-by-room Heatloss calculation. We use 2" fles duct and 3" flex duct, (one 3" flex= two 2" flexes). We have no single complain about noise at all. Now we have new fan-coil on market HE-V model c/w new energy efficient motor, two stages of heat, two stages of cooling, completely new control circuit board. The new circuit board equipped with dip switches that set fan-coil blower to proper speed based on actual number of vents, heat/cool load. The HE-V can be designed with 2-4 Heating/cooling zones but it can be done only, with proper condenser (modulating) and trained contractor. Nick

Unknown

The higher the relative humidity during the cooling months, the more comfortable and efficient these systems become.

They do though require good engineering. Pay particular attention to trunk (plenum) design--a "loop" system is best--and required outlets per ton. Understand that there is a "standard" branch length. Use shorter and there's more of a chance for noise--use longer and you have to de-rate due to the increased resistance in the branch.

Marty_7

efficiency

They do show lower SEER ratings than conventional units. What they do not tell you is they dehumidify better than a conventional system and they have almost no duct leakage. When you look at the overall system efficiency of Hi Velocity compared to conventinal ducted systems they are typically more efficient.

Unfortuneately, the SEER ratings on all systems do not consider duct work.

We sell a lot of Unico. If properly installed it is a great system.

Unknown

Well,

I just put my first two Unico 1218 in but I haven't fired them up yet. I talked to Unico beforehand and they were ok with what I was doing. I split the ductwork in two and installed two 6" trunks off of a common plenum. This is way oversized. I also have dampers at the beginning of each trunk to help add resistance. At this point I have no desire to make them automatic. I did this because it's a recording studio and each bulding has a recording area and a non recording area. The idea is to put as much air to the recording areas as possible without making any noise and have the rest of the system(s) suck up the excess air pressure. I plan to start on low speed and hopefully will stay there. Anyhow MY question is how do I set this up in terms of motor amps? I see the tag on the unit giving amps draws for each speed. Is this what I shoot for? How much leeway do I have before I shorten the life of the motor? We used metal round all sealed and I did reduce as the runs got farther away. There are no loops. The MAIN function of these systems is to dehumidify.

Unknown

I've only designed two and installed one Hi-V systems (both Unico). The first, double-branch design (about as far away from the "ideal" loop system as you can get) got me a job offer from the company president.

For the one I installed, I didn't use an ammeter--just a good old fashioned "U" manometer with the main unit damper open as far as possible and the fan as slow as possible. I won't say it's silent, but it's very quiet

One thing I forgot to mention is to install Hi-Velocity systems as if they were intended to contain water.

Unknown

Thanks Mike

You make me feel like I'm on the right track with these. I'll know more soon enough. The plan is to turn the studio branch down to 25 cfm per outlet, see whats happening with the other branch wide open and take it from there.

Man with a question

ESP Hi-V air handlers

I am surprised to hear anything negative about the ESP product.

They are terrific. ECM motors. Smart Circuit board with on board pump relays.

Dip switch controllable air flow.

I love their gear. I use their conventional static pressure fancoils as well.

In all fairness, what are the problems you have heard?

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Marty_7

Where are you

MPF, where are you located? There is a way to balance the system using the static plate that comes with it. If you are in the New England area we may be able to come help you out.

Unknown

Central CT

The units did not come with the static plate and my supplier could not supply one. I'm under the impression the plenum dampers will serve the same purpose. I appreciate the offer, you're more than welcome to come and have a looksee.

AZ

I have heard a few different issues, from problems with interfacing with separate components, to problems pertaining to the board (I realize all electronic components will have their problems, however, in my area I have heard more than a few installers complain about them).

Unknown

Update,,,

Talked to Unico this morning. As long as FLA draw is not exceeded, amps are not an issue. The issue is with having the proper airflow for a refrigerant based cooling coil. As mine are fed with chilled water that is a non issue as well. My mind is now at ease.

Mark_46

I have a 1218 and a 2430 Unicos - installed in mid 2006. They are used for cooling and primary heat (heat is via water coil). No quality problems/failures so far. I am a little disappointed in the system noise though. But I think it has to do with installation rather than the system type.

Unico's tech support was good too.

However, because they are manufacturing systems (except for the plenums) that should be in synch with itself when installed properly (CFM,GPM, static pressures, etc), I think something Unico could improve on is who is installing their systems and how. They need to keep tighter control on install quality (duct leakage and joint sealing, plenum insulation, takeoff positioning, duct supports, etc).

Similarly, an install should be tuned (CFM, static pressure, outlet temps, delta t across coils, water temps GPM) before being considered complete. As well as things not specific to Hi-V like superheat and subcool checks.

There are too many outfits out there who basically...dont read the instructions and wind up delivering systems that are pretty upsidedown.

Eugene Silberstein 3

High Velocity

Hi velocity systems are, for the most part, great systems. As with any system or other piece of equipment, the overall operation of the system is directly related to the quality of the installation.

Over the years I have encountered many individuals who absolutely hated hi-velocity systems, and the reason for this hatred was very simple. When installing the units they failed to read the instructions and, as you might have expected, the units failed to operate correctly.

Remember, it always pays to read the instructions. There are some of us in the trades who will not look at the instruction booklet for fear that the homeowner will see them. If a customer comes up to and asks. "Why are you reading the instruction book?", you can always respond by asking, "Would you rather I installed your equipment without reading the instructions?".

Unknown

That must be,,,

what I did right, I read the instructions. I fired up Unico 1218 #2 today. This one is hooked up to the larger system. We ran the duct just like any other except we designed for 400 CFM at 1.5" static pressure which reduces duct size considerably. We used round pipe and reduced as the trunks got farther away. The unit came right to amp specs with everything wide open and I find there to be little difference in velocity from the outlets along the entire system. Again though, using chilled water as opposed to DX coils greatly simplifies matters. Airflow across the coils is not an issue with CW so you have much greater leeway with how you set these up.