Water Chillers & Boilers?

[DonTx]

Every once in a while I get a condo here that has a chiller & boiler operated HVAC system (at least I think that's it).

These units usually have drop ceilings and there will be an A coil somewhere with a valve that you turn one way for heat and the other way for A/C (best I remember). Boiler (and chiller?) are centrally located to serve a group of units.

Can someone point me in a direction to find out more about these systems? Any advice on what to watch for when checking them out?

Donald

[a46geo]

Don,

Use the manufacturers name and model number to do a google search.

I don't know about your state, but here in Michigan they are STATE inspected and certified.

Whatever you do, don't be turning any valves, and don't show anyone what to turn. These things are best left to the experts.

George

[Terence McCann]

Amen George.

The older systems consisted of a 2-pipe system. You had to wait for system to cool down after the boiler was running before starting the chiller - pop a relief valve and dump a whole bunch of freon. Some of the larger complex have centrifugal chillers and these are a beast unto themselves. Suction pressure is measured in vacuum and the head pressure runs about 5#. These systems also have cooling towers that need attention. The newer systems might be 4-pipe (which will allow you to run a/c at the same time as the heat) but these are far and few between, to costly to install.

Anyone with less than 10 years of pure HVAC service tinkering with these is asking for trouble.

[hausdok]

Hi,

Don't know if it is the same system, because it's been so long, but I had one in a downtown highrise condo a few years ago that sounds like this one.

It consisted of an A coil inside an air handler with water circulating through it. Turn it to hot and water from the central gas boiler in the basement circulated to the unit and through the coil. A blower in the air handler forced air through the A-coil to heat the home.

Turn it to cold and cold water that circulated through a coil inside a central AC plenum was cooled and then passed through the A-coil to send cold air into the home. It was equipped with a condensate pan and drain as well, but had no refrigerant circulating through the system inside the condo. In truth, the A coil had two separate sets of lines running through it, not one as in an AC system or Heat pump.

Since it very rarely makes it into the 90's here in the hottest part of the year, the occupants of this building said that this unit made their homes very comfortable in summer here.

ONE TEAM - ONE FIGHT!!!

Mike

[DonTx]

Mike, THAT'S THE ONE!

The several I've seen have a boiler or 'who knows what' at a central location somewhere in the basement or complex. The ones I've seen are in a high rise of apartments that were turned into condo's. The management would not allow me access to the guts of the building so it was easy to disclaim it and point the finger at the building maint. people. I was more than happy to do that.

George, Terence, et al, would this type of system that we're talking about be inspected by the state as well? The unit that is coming up is a condo unit built in 1966.

Thanks,

Donald

[a46geo]

Don,

It would be a state issue here in Michigan. My state also affixes an official inspection sticker. Look for one of those if you can't get any information from the State of Texas or their web site.

You might also want to check with your own insurance carrier to see if they have any "keep away from ..... whatever" clause.

Let us know what you find out.

George

[Terence McCann]

Hello Don:

The boiler would be as it's a pressure vessel, the insurance company also inspects boilers. I doubt that they would check the chiller.

What I always find amusing is when they find a issue with a boiler that has been in operation for years and they have been inspecting it for years. Job security.

[Chad Fabry]

I have two boilers at my shop and all commercial boilers must be inspected each year where I live. The fee for this mandatory inspection is 150 bucks per boiler.

EVERY year I have to add some control or change another one to a new different type of device. I have so many safety devices on these things I have to say a prayer each day to get em fired up. I shouldn't say this out loud, but no one's ever called the fact that they sit on the floor in a vehicle repair shop where there's flammable liquids everywhere you look. But when the building's ablaze I'm secure in the knowledge that my boilers have manual re-set high limit switches.