Unico Unichiller

Patrick Kozak_2

Has anyone had good experiences with the Unico Unichiller unit as compared to a regular AC unit? I'm considering using one with either the Unico mini-duct system or the Mestek Space-Pak system.

Wayne_12

Unico

Listing what concerns you have will help to identify the advangages/disadvantages. The Unico system operates very simular to a a/c system in the cooling function. Unico has distinct advanages when it comes to duct access issues. Smaller duct, and allows the use of a hot water coil for space heat or electric heating elements.

If a/c is the only concern and duct work issues can be addressed, the hardware side of the equasion will cost more than a air handler. You need to check everything.

Patrick Kozak_2

Unico Unichiller

Thank you for the information about the air handler side Wayne. My specific concern was about the Unichiller unit which is the outside unit that produces chilled water to be delivered to the coil in the air handler. What advantages or disadvantages does this chilled water type have in comparison to the regular AC outside units that use refrigerant to cool the coil? Or am I confused about how a regular AC outside unit operates?

clammy

unichiller

is this a stanard a/c condensing unit with a barrel or plate exchanger to chill the water?or is it a water cooled instead of air cooled condenser also does that outdoor units heat exchanger have to be winterized to prevent damage ?i know that the chilled water coil will have more area and give better humidity removal and with the use of 3 way valve can real give some excellent temp. controll but is it worth it. while on it if your using chilled water why not use a ammonia .arkla servel used to make gas fired out door chiller that probaly out last the best condensing units with a very small electric draw .i would thing thata better way to get chilled water then a plate exchanger hooked to either a standard residental condensing unit or small commerical refrigerant condensing unit.why not have a stanard split a/c systemput in and are the guys selling this in your opion truely cpable of servicing the unit andf ensuring that it's really going to work and be as engery eff. as they state.not trying to knock anybody but juct interested good luck

Patrick Kozak_2

Unico Unichiller

Clammy, its a water cooled unit (Unico Unichiller)so it has to be winterized with glycol. but there is no plate exchange unit involved. It supplies chilled water directly to the coil in either the Unico mini duct system or to the Mestek Space-Pak system. My alternative unit I've considered is the Servel unit fueled by natural gas. This unit costs dollars upfront, but the Servel unit will last a very long time, and if I play the natural gas hedging market successfully I can save some cash,lol, unless I run into some ex Enron employees like Ken Lay.

Glenn Harrison

Patrick,

may I suggest you stay away from the Servel chiller. I have about a dozen of these units out there and they are constantly having problems. Ignition controls, electrodes, water pumps, fan proving switches, etc. etc. all seem to last a short time on these units, plus we had one unit two years ago, five years old, that lost the hydraulic pump which contaminated the entire ammonia side of the system, and another unit last year that the generator chamber started leaking ammonia after only 11 years of service. Plus, a Servel is typically 3+ times the cost of a central air unit.

Glenn Harrison, Residential Service Techician

Althoff Industries, Crystal Lake, Illinois

Althoff Industies Link

Patrick Kozak_2

Servel Problems

Glenn, thank you for the warning from personal experience. One thing I don't need is maintenance problems.
Sincerely,
Patrick

Glenn Harrison

Your welcome.

I just wish I could help you with the original part of your question. I work for a Unico dealer, however, all the units we put in are using regular A/C units with refrigerant evaporators in the attic. I was looking at the Unico website at the Unichiller unit and it apears to be a slick alternative to the standard system. The only thing that always worries me about a chilled water system in a residential setup is the need to maintain the glycol strength and acidity, or draining and refilling the unit for every season, and the posibility of a water line or the coil freezing/leaking and causing a major mess from the attic down. Other than that I can't say good or bad things about it, but since it's a Unico, I would think it would be a good unit. Now that I see that unit I'm wondering if they will come out with their own line of split system condensors too. HMMMMM.

Glenn Harrison, Residential Service Techician

Althoff Industries, Crystal Lake, Illinois

Althoff Industies Link

Patrick Kozak

Glycol mess solution?

Glenn, How about running the glycol filled chiller feeds from the outside unit through a PVC or CPVC pipe up to the attic air handler. That way if the feeds leak the mess will drain to the outside. Also, put a safety pan under the air handler containing the coil with a drain to the waste water system.A few dollars upfront, but at least if it leaks I can save on the insurance deductible.
I know you are a Unico dealer, but what is your opinion of the Mestek Space-Pak. My father worked at the original Mesta Machine Company for 40 years until it went bankrupt.The Reed family merged with the Mesta shell after it went bankrupt to use the $40 million net operating losses it could carry forward. My brother continued to work for Mesta Engineering as the assistant controller until it closed a few years ago. Maybe I can get a free Space-Pak unit since my widowed mother lost her survivors pension when Mesta Machine went into bankruptcy. Its the least they could do considering they reaped $16 million in direct taxes saved from the net operating loss carry forwards.lol

john wood

Chillers are good!

I like them as you can use one chiller with multiple a/h. Also; Even if customer never changes filter, they do not freeze up! Big Plus. Thirdly, you don't need to worry about refrig licence or too long refrig lines and oil return to condensing unit. You could also look at ESP's HiV system. Similar to the other two with some added advantages in my opinion.

Glenn Harrison

Good point.

The pipe idea is not a bad idea. We don't install these, just service previously installed ones. And of course I would definatly agree with the secondary drain pan.

As far as Space-Pak goes, I have no problem with them. Just as good of a unit. The two things about the Unico are that since it is a modular unit, it tends to be a easier to install and work with (words of our installers) and since it has a adjustable static pressure plate that is set per the specific air flow/tonnage being used, the system is a little more precise and a little more forgiving to ductwork oddities. Plus I just attended a Unico class and found out they have made some improvments, such as a T.X.V. that is easily removed with wrenches, and accesible at the side panel, a reostat so you can set the unit to run a constant LOW speed fan, and now the systems come in three sizes for improved cooling and efficiency. Now on the other side of the coin, maybe Space-Pak has made changes like this also, and I'm not aware of them. You would have to check with Space-Pak to see what the latest and greatest with them is.

Hope this helps.

Glenn Harrison, Residential Service Techician

Althoff Industries, Crystal Lake, Illinois

Althoff Industies Link

John Mills_3

Air cooled condenser

This unit has an air cooled condenser. Looks like the Multi-Aqua, is it?

Patrick Kozak_2

T.X.V.?

Glenn, Thanks again for the information. Just one more thing. What is a T.X.V.? I'm not in the trade, just a future home owner and could have been engineer designing my new home.

Glenn Harrison

Thermostatic eXpansion Valve

It's the device that controls the refrigerant flow thru the Indoor (evaporator) coil. This i not real important to you, but I mentioned it because it used to be a nightmare to change a T.X.V. on a Unico or Space-Pak if it were to fail. Now it's easy as pie to change.

Glenn Harrison, Residential Service Techician

Althoff Industries, Crystal Lake, Illinois

Althoff Industies Link

chris smith

chillers

chillers can have some advantages over conventional split units, one is the freon side of the unit is all made up at factory this means ideally better cleanliness, no leaks, correct amount of refridgerant added at factory, [all thease items must be checked on the job sight] for the non expearianced installer there can be other plusses, if your air handler is above your condenser on a split you must trap your return line, no txv to install, no bulls eye no filterdryer, no special tools like vacum pumps, nitrogen bottles, no silver soldering or brazing to be done, another plus is they zone more like a heating system so your controls will be familiar, on both systems you must insulate your piping, leak test, and remove condensate,




Chris Smith

paradise porter maine

Patrick Kozak_2

Chris, Thanks for the information. With the ease of installation for a chiller I hope my installer passes some of the savings on to me.