Water loop design 1

[Andy191]

There is the question about water side of HVAC system. I plan to use a 1 degree c chilled water loop to keep coil's LAT of AHU at 4.5 degree c. Is there any concern of 1 degree c water loop design?

 

[LittleInch]

Concern about the pump or in general? Well apart from freezing and lots of condensation on any exposed part it will depend on what the "water" is - I assume you have some anti freezing in this?

Rather a vague question so rather a vague answer I'm afraid. Provide a few more details and what YOU are concerned about.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Andy191]

Assumption propylene glycol antifreeze in water, in worst case, water leakage of cooling coil will make it through air to contact with oral pharmaceutical product. That’s the reason why the 1 degree C water without any antifreeze I want to design. Is it possible to use suitable component in piping selection and well insulation to prevent them from condensation and freezing in practice? Or, it is NOT possible for “the 1 degree C water without any antifreeze design” in practice.

 

[itsmoked]

I doubt it's possible. You'd probably have ice build-up on the chiller. Lowering the freezing point a couple of degrees with something 'safe' might be possible though.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[LittleInch]

That was my concern - to get to 1C your chiller will need to be below that unless you have a very long residence time and limit the chiller to 1C also, bearing in mind the accuracy of thermocouples and equipment is rarely accurate enough to not dip below 1C.

I think you may also star to get ice chystals forming if not going completely solid, but enough to start blocking tubes and affecting pumps.

Materials and insulation isn't an issue, but I think you need to try a different fluid.

There is an HVAC forum in the mechanical engineers list. They might be able to provide more experience than the pumps forum....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Andy191]

The glycol chiller and AHU use heat exchanger to separate glycol water loop and chilled water loop, so glycol chiller loop will has antifreeze to prevent ice-built.

 

[LittleInch]

But only on the gycol side....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Andy191]

Thanks all the reply.
It seem no project in practice of without antifreeze in 1 degree C chilled water loop. From point of safety design, it should has antifreeze in lower temperature water loop design.

 

[ProcessHVAC]

This is an HVAC question, but in general sounds like a bad idea.