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o.k. looks like poor execution then....

Originally Posted by carmon

looks like a poor idea....

Not really a poor idea, just poor execution. Here's a quick google result example of a bit better execution of the same idea: http://www.piec.com/precooler.htm

looks like a poor idea....

Things are starting to get a little crusty now. But, pad appears to be doing it's job. Here's a pic taken today.

Those ducts are nuts! I have seen duct extensions made for economizers in cases where there was a gas fired appliance discharging its flue close to the economizer intake and a few times to avoid kitchen hood ventilators, but this doesn't appear to be the case at all here. Someone probably thought that the air near the roof might be a lot hotter than the air 6 feet up?

OMG they invented a water cooled condenser- WOW I wish I would have thought of it first. Maybe they can use the water for some heat recovery. Hay I think I'm on to something. And there are some systems I have run a hose on for temporary reasons.

Seems like a good idea for a problem system. Would not put that on a new system. Looks like crap. Hope he did not invest his life savings on that.

Originally Posted by craig1

i recently removed a homemade misting system from a carrier RTU. It pretty much destroyed the coil in one year. 3 bottles of CLR latter and most of the mineral buildup is off of it.

Then I split the coil and cleaned it and theres no more problems with it tripping the breaker due to high head pressure (which was the reason that someone installed the mister)

So you removed a band-aid did it hurt ?

i recently removed a homemade misting system from a carrier RTU. It pretty much destroyed the coil in one year. 3 bottles of CLR latter and most of the mineral buildup is off of it.

Then I split the coil and cleaned it and theres no more problems with it tripping the breaker due to high head pressure (which was the reason that someone installed the mister)

Originally Posted by VTP99

I have seen those animals at the circus
Is that control box blocking any air flow ?

I didn't do any checks on these 2 systems. But, the condensor TD didn't feel any different than a unit without it. And again, this was just using me waving my hand over the ODF after washing them!! Serious, any sort water on a big rooftop is a welcomed sight to me as it really starts to get Hot!!

Originally Posted by KB Cool

Maybe this duct work has a purpose. I don't know! And the misting system? Maintenace guy said unit is now putting out 4° lower supply temps.

I have seen those animals at the circus
Is that control box blocking any air flow ?

Originally Posted by CraziFuzzy

A 'better' way to handle the evaporative add-on is to do it remotely. Not misting directly on the unit, but using basically a swamp cooler type system to ducted to discharge the much lower dry bulb air on the condenser, without actually wetting it.

Yeah, we got a customer thats running cellulose pads on various large carrier RTU's. The wet section is made of stainless steel w/ temperature activated water pump. We replaced the pads not too long ago and the condensor's didn't look bad at all. Mainly just dusty and no calcium build up at all and they do run at a much lower head pressure.

Originally Posted by southeasterntec

I see they are Selling this thing for $490.00 EACH! 4 AA batteries included. What a deal!
I have never seen this before but I have seen people useing garden hose on top of roofs to lower there cooling bill (Right) cut there cooling bill by $5.00 but raise there water bill $500.00

Playing a bit of devil's advocate, but equipment damage aside, the water systems can save a ton of money on operations cost - depending on the climate. In a dry climate, they will result in a MUCH lower head pressure. The only problem with retrofitting them on systems not designed for it (like here) is that it has the potential to eat up the condenser coil. There is technical merit behind the theory, just a trade-off with either maintenance cost, or equipment life. Using soft water would greatly reduce the equipment damage potential.

Keep in mind, they DO make evaporative condenser based RTU's, which is basically what this is - it's just the ones designed for it are designed to withstand the potential damage the water might provide.

A 'better' way to handle the evaporative add-on is to do it remotely. Not misting directly on the unit, but using basically a swamp cooler type system to ducted to discharge the much lower dry bulb air on the condenser, without actually wetting it.

I see they are Selling this thing for $490.00 EACH! 4 AA batteries included. What a deal!
I have never seen this before but I have seen people useing garden hose on top of roofs to lower there cooling bill (Right) cut there cooling bill by $5.00 but raise there water bill $500.00

Originally Posted by Nuclrchiller

Ok, the thing on top had me wondering. I see now it is the "control box". At least they acknowlege the effect of minerals on the coil. Still, others will have to use their units to prove to me that no harm is being done to the unit. I'll pass.

The customer is testing it on 2 units right now. They have a total of 48 RTU's on that building.

Originally Posted by Nuclrchiller

As far as that other device, I'm not exactly sure from the pics what that is.

It's a "handwasher" for HVAC service techs like myself!

Ok, the thing on top had me wondering. I see now it is the "control box". At least they acknowlege the effect of minerals on the coil. Still, others will have to use their units to prove to me that no harm is being done to the unit. I'll pass.

My old company was once in an older, newly renovated building. Office workers complained about a bad odor. When I went up on the flat, gravel covered roof, I was shocked and disgusted at all the bird crap that was up there. I just shut and disabled the outside air economizers . Perhaps if I had been more creative I would have thought of such a solution as that ductwork. As far as that other device, I'm not exactly sure from the pics what that is. Google, here I come....

RTU

Maybe this duct work has a purpose. I don't know! And the misting system? Maintenace guy said unit is now putting out 4° lower supply temps.