Need big help with system

[Neal Lewis]

OK, I think what we have here installed at a single family house is an exterior chiller/heat pump and some type heat exchange unit on the interior. There are hydro-air air handlers to heat the house.There's also a hot water boiler for backup heat. Help me out with this one.

Click to Enlarge

26.67 KB

Click to Enlarge

41.47 KB

Click to Enlarge

62.16 KB

[Bill Kibbel]

From the 2 pictures, it sure looks like the components of an evaporative condenser for cooling. I don't think there's any heat pump involved. Heating is supplied by the boiler. I've seen many at commercial and industrial building inspections, but only one at a "residence". It was a very large historic house museum with additions for offices. What size was this house? I thought evaporative condenser cooling systems were 10 tons or larger.

B. A. C. is probably Baltimore Air Co., which I think is a big manufacturer of evaporative cooling equipment.

[Bill Kibbel]

This might help describe the system:

Click to Enlarge

30.47 KB

I've got lotsa printed stuff on evaporative cooling I could send you, but Terry could probably give you a condensed course that's probably better than what I have. Were there any water treatment systems? Any maintenance records?

[Terence McCann]

How many square feet is that house?

A lot more pictures would help but I'll try to help with what I see.

As Bill said BAC stands for Baltimore Aircoil Company http://www.baltimoreaircoil.com/english/

The outside unit is just a cooling tower. If it were an evaporative condenser you would see four pipes going to it.

From BAC:

Principle of Operation

The vapor to be condensed is circulated through a condensing coil, which is continually wetted on the outside by a recirculating water system. Air is pulled over the coil, causing a small portion of the recirculating water to evaporate. The evaporation removes heat from the vapor in the coil, causing it to condense. http://www.baltimoreaircoil.com/english ... condensers

A very basic description would be the condenser coil from an air conditioner sitting inside the cooling tower. Water then is pumped over the condenser coil - using water instead of air to condense.

The second picture is a heat exchanger. It maybe a shell&tube or a tube&tube but I can't see where all the piping goes to make a determination on type or purpose.

Did you see a chiller? You say there is a boiler, were you able to trace this piping? How many AHUs were there? You say there was water piping going to them, were you able to trace it out?

It could be a few different systems but I would need more information to make a call. More pictures would help too.

[Neal Lewis]

Terry, yes four pipes going to the outside unit to the inteior coil exchanger(big tube thing, which was warm)

Bill, the boiler was cold until I fired it up for the baseboard zone in the basement.

See if this pic will help.

Click to Enlarge

37.73 KB

[Terence McCann]

Were did this line go Neal? It looks like a drain.

Click to Enlarge

63 KB

[Neal Lewis]

Terry, I found out that the pipe is to drain down the cooling tower for the winter.

This unit is capable of 14 tons, and probably only needs 4-5 for the house. There are water source heat pumps/compressors in each of the air handlers that work in conjunction with the High K heat exchanger (the big tube) to heat the house. The hot water boiler is also piped into it for emergency backup.

[Terence McCann]

That's what I thought Neal. There are only two lines going to the cooling tower then - it's a cooling tower only.

Do you have any pictures of the air handlers Neal? How many air handlers were there? Was the water piping going to the AHUs?

It's almost sounds like you have a water source heat pump installation but I can't be sure. In the basement, by the boiler, did you see a chiller (compressor, piping etc)?

The owner of the home must have owned a HVAC distributorship because that system is really overkill.

Click to Enlarge

65.36 KB

[Terence McCann]

Ok Neal, sounds like you got some more info then, good.

Take a look at the PDF for some more information of this type of system.

http://www.mcquay.com/mcquaybiz/literat ... s/1002.pdf

[Neal Lewis]

Thanks Terry

[Terence McCann]

Just a few more comments regarding the system Neal.

This system really sounds like an HVAC tech got his hands on some "stuff" from "fill in the blank" (God only knows where). The system is completely unorthodox (for this house) and it's a pretty good bet that 0 engineering went into the system. This is a system you would see in commercial office buildings that wanted cost effective zoning. Also, there are gross inefficiencies that are inherent when one over sizes equipment such as this. 14 tons = 168,000 BTUs. At 600 sq ft per ton your looking at 8,400 sq ft. If you had the BTUs of the boiler and water source heat pumps we could do the math however I'd punt.

The boiler is not for backup with these systems but to inject some heat into the loop in the winter time (so the water source heat pumps can operate correctly in the heating mode).

It's nice that they put the cooling tower so close to the home too. Perhaps they could hang some rain forest Flora close by - they'd love it. If you ever see what looks like steam coming off the roof of a commercial hi-rise office building, in the summer, it is typically the cooling tower plume. Look at the cooling tower of a nuclear power plant for a good example. This system won't produce a plume anywhere close to that but you get the idea. Do you want that by the home? It is also proven that Legionnaires' disease can come from cooling towers (the bacteria love the nice warm water - hence proper water treatment).

I could go on but you get the picture.

Good luck calling your local residential HVAC company when something goes wrong.

[:-crazy]

[exploreparadise2]

That cooling tower looks old. It needs to be cleaned regularly and the water has to be treated. According to the Cooling Technology Institute, 40-60% of cooling towers are contaminated with legionella.

Download Attachment: Cooling Tower Maintenance.pdf

222.63 KB