humidification for cold climates

[evapcoil]

Good afternoon Colleagues
I am researching on humidification in centralized system in very cold climates, the system that I work on need to perform from +35°C to -10°C, now We are running in a temperature of 0/-2 and the environment is really dry.
I am considering the option of installing a humidification system for next season but I would like to hear the opinion of people who might have worked with this equipment in the past.
On the makret there are different types:steam, cold water atomization, and so on.
So I am asking if anybody have any comment on this , to let Me know, this can be very helpful in choosing the right type.Pros and cons of the type you had work on will be appreciated.

[Brian_UK]

Where are you? 'On the sea' doesn't help a lot.

[evapcoil]

Hi Brian
We are actually sailing in Antarctica, and We will be back here next year for another South Pole season.
I work on cruise ships so I cannot tell you a specific area as my ship travel all over the world.

[Brian_UK]

That's fine, just trying to get a feel for your areas problems.

[Brian_UK]

I would investigate water atomisers.

Steam generators would include the ongoing costs of replacement steam bottles. Empty bottles both new and used all require storage space which I would assume is a valuable commodity on board.

[Magoo]

Hi Evap.
hope you are not on the ship that got stuck in ice flow a couple of weeks back. Scary!!.

As per Brian UK, add atomized water. Similar problem as per data centres, all sensible heat load.
Alternatively some outside air make up although cold it will be high moisture content, lower the pressurization and recirculate more return air. Monitor oxygen content though, do not want everyone nodding off.

[northernbeach]

I am agree with you, very well said.

[evapcoil]

Hi Guys

Thank you very much for all your replies, and your concerns :-) Luckily We are sailing on the opposite side of the Antarctica continent, and We were quite lucky with the weather just few storms but nothing out of the ordinary.
Regarding the topic, We thought about using steam but it would be a problem to bring the pipelines up the upper decks, so We were going toward the idea of water atomizer ar you guys suggested.
Has any of you already work with this systems? Does the water sprayed in the AHU created any issue in the ducts system? Such as extra rust or anything else?

[evapcoil]

PS: I forgot to mention, on some unit We run with 100% fresh air no recirculation, on some others We have a part of recirculated air, but still it does not help due to the very low humidity of the outside air.
humidity outside is almost not present.

Thanks again for helping and reading this thread.

[Magoo]

Hi Evapcoil.
perhaps atomized water onto heating coil, air on face, gets moisture into suspension and reduce carry over to ducting.

[evapcoil]

Hi Magoo
Yes, I agree, this was actually the solution that I was more attracted too, in this way the reheating coil would act as a drop eliminator.

[Gary]

Alternatively some outside air make up although cold it will be high moisture content...

Ummm... cold air has low moisture content. Outside air is the problem, not the solution.

[Gary]

PS: I forgot to mention, on some unit We run with 100% fresh air no recirculation, on some others We have a part of recirculated air, but still it does not help due to the very low humidity of the outside air.
humidity outside is almost not present.


As a general rule, when the outdoor temperature drops below 10-15C (depending on RH and indoor temp) it starts to dry out the indoor air.

With 100% fresh air intake:

If the outdoor temp is 10C @ 100% RH and the indoor temp is 21C the RH will be about 50%.

If the outdoor temp is 10C @ 50% RH and the indoor temp is 21C the RH will be about 13%.

If the outdoor temp is 15C @ 100% RH and the indoor temp is 21C the RH will be about 70%.

If the outdoor temp is 15C @ 50% RH and the indoor temp is 21C the RH will be about 32%.

At some point between 10C and 15C outdoor temp, the fresh air starts to cause low humidity problems and the fresh air intake needs to be minimized (keeping in mind the need to breathe).

[evapcoil]

Thank you Gary for your inputs.

[Gary]

The greater the problem, the more difficult the solution. If you can find ways to reduce the fresh air intake you reduce the problem... and it becomes more manageable.

Then look for ways to add moisture.

You're welcome.