Re: [PSUBS-MAILIST] Humidity control

[Jon Wallace <jonw@psubs.org>]

I calculated the dew point in the cabin during this dry test to be between 77F and 78F degrees based upon the data provided in the PDF file that was attached.  Since the outside temperature was averaging 70F this explains the condensation on the viewport and surrounding area.  However, the syntactic foam must present some pretty good insulating qualities and my recollection of your design is that the outside of the pressure hull is completely sealed from the water.  I can understand the condensation on the viewport, but I sure would be surprised if you had condensation further in the cabin.

Jon


On 3/16/2011 5:49 PM, Cliff Redus wrote:

Sean

 

Shop.  Yes, the ambient air temperature in the shop started at 70.6F and ended 8 hours latter at 69.7 F.  Yes, pressure hull is not insulated on inside but has a nice syntactic foam insulation on outside.  Condensation was observed on viewport and inside of the sail.  As boat has close quarters, I can't  see aft to see if condensation was occuring.  My guess is that condensation was fairly uniform throughout the inside of the pressure hull.  I am not sure if the steady-state condensation rate was equal to the respiratory water production rate.  It might also be that the scrubber was absorbing some of the water vapor. I concur that amount of liquid water will be related
directly to dive duration.  I think conditioning the air would be great if you do it easily.  I am still not convinced that for a microsub like mine that it warrants the work or the required equipment space.  It would be nice not to have to worry about the impact of high RH on my boat electronics as we discussed in Vancouver.

 

Cliff