Hi Alan,I have to say that I'm a bit surprised to hear that the DryDive sub has problems with the environment being too hot. Is he operating in warmer water? There's a couple things to keep in mind on this topic. First, the hull and other other parts of the sub in direct contact with the water are going to match the ambient water temperature. This will happen alot quicker with a metal hull than a fiberglass hull like you are working with. However, your hull will also eventually reach ambient water temp as well. Once at water temp, your sub becomes a huge heat-sink and will constantly be drawing any warmer air in the cabin out to the surrounding water by conduction. Your hull will be less efficient at this than a metal hull, but it will still occur. The missing factor that I don't know is the rate of heat transfer which would determine the length of time before temperature equilibrium is reached. This would partly be determined by the insulating properties of the hull (which a metal hull would be very poor at) and the combined heat of people and electronics that were constantly being transfered into the cabin air. While your fiberglass hull is a better insulator, it is still thin and the "R" factor is probably negligible in terms of heat transfer resistance.
I believe DryDive can accomodate more than one person. Did Brent specify the number of people on board when there was a heat problem? According to the specs of his sub, he can dive 35 minutes for 100 minutes. Does the heat problem still exist after a dive at depth?
Jon ALAN JAMES wrote:
Hi Frank, It's body heat + exhaled breath heat.I have a polystyrene full size model of the inside of the sub that I sit in occasionally and know that it heats up quite quickly. I'm going very small so what may be a problemto me mightn't be for bigger subs.It's difficult to determine what's going to happen temperature wise. I may try and get Brent involved as his comments sent me on this path. The transmission cooler I'm considering is only 280 x 140 x 19 mm + fan. If I need it it's there. If I don't design it in I won't have room later. The intakes will add to the aesthetics. Also if it's a total waste of space I can insulate it, sterilize it, put an air line on the intake and one of those beer dispensing guns they have in pubs on the outlet. and fill it with beer. This latter idea may get me a nomination for the psubs "HALL OF FAME AWARD"Thanks for your thoughts Alan
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