Does cold water increase air consumption?

[String]

One reason you consume more air when the water temp is low is the body works harder to keep your temperature within its normal limits and thus burns more air.

Thats being cold vs cold water.

You can be warm in cold water, you can also be cold in warm water.

 

[CJ Waid]

I found just the opposite of everyone else, I went ice diving in water in the 30's wearing a wetsuit, and I found that I used about the same if not a little less air.

BUT, it might have something to do with being comfortable in cold water.

You are suppose to use more air in cold water, but I honestly think I use more in warm water, probably from moving around more carefree or something.

 

[drbill]

Yes, definitely (in my case at least). I get pretty good mileage out of my tanks here in the cooler waters of Catalina, but am really impressed with the bottom time on a regular Al-80 when I'm in the tropics! Love it.

 

[Xman]

also, if diving wet, you'll wear thicker neoprene. Thicker neoprene mean greater buoyancy swing when the wetsuit compresses at depth. This will mean more air in the bc along with more lead, and increase air consumption.
I think if you are not used to cold water, then your trim will probably be off with the greater weight if diving wet also. This will also affect air consumption.

 

[fisherdvm]

Firstly if true it would only happen with a suit monstrously tight to the extent you'd never dive it, secondly the shrinkage if any is 10ths of a millimetre so not a factor
That is the only part thats true.

String, I am not talking about shrinkage or expansion, which is an intrinsic property of all solids.

I am talking about elasticity. Plastics lose significant amount of elasticity with low temperature. I do not know much about neoprene, but I am sure there is a constant that is a measure of this for neoprene.

 

[String]

I am talking about elasticity. Plastics lose significant amount of elasticity with low temperature. I do not know much about neoprene, but I am sure there is a constant that is a measure of this for neoprene.

So small as to be statistically insignificant. And if the suit isn't uncomfortably tight to start with it wont have any effect at all.

 

[Gene_Hobbs]

Respiratory effects from cold water immersion research is an interesting topic. (not much time before my next class comes in, so this will be brief.)

Respiratory and cardiovascular responses to cold stress following repeated cold water immersion.
Muza et. al., 1988
In: Undersea Biomedical Research
RRR ID: 2484

The beginning of this paper sums up the research:

Respiratory responses to cold stress have received relatively limited study and generally cover only single, acute cold exposures. Generally, minute ventilation increases progressively in response to the increasing metabolic demands of the cold stress (1-4 EDITOR'S NOTE: The JAP references used here are available online.) Resting minute ventilation has been reported to nearly double during an exposure to 8 degree C air for 2h (4). In the case of cold water immersion the intensity of this ventilatory response is inversely related to the water temperature (5) and may play an important role in determining whether the victim inhales water. Control of the pattern of breathing during mild hypothermia has not been studied. Also, the effect of mild hypothermia on the chemoreceptor inputs to the control of breathing is not known. Nor has the respiratory response to cold stress before and after acclimation to cold been investigated.

Cardiovascular responses to cold stress vary depending on the nature of the cold stress (air vs. water, whole body vs local exposure, ambient temperature, and duration of exposure) and the metabolic and neurophysiologic status of the organism being stressed...

Prolonged whole body immersion in cold water: hormonal and metabolic changes.
Smith et. al., 1990
In: Undersea Biomedical Research
RRR ID: 2558

This paper is probably overkill for this discussion but there were several references here that are applicable to the present conversation.

So, the answer is yes it does and how much it changes is based on a long list of other contributing factors. Examples already covered in this thread: passive thermal protection, work performed, breathing gas temperature, and water flow through and around the suit (suit compression, current, scooter, etc.)...

Nice post:

It would seem that the real answer would be related to how cold the diver is. If the protection against cold compensates for the water temperature properly, then the only way heat could be lost is through the respiratory heating of cold air coming in from the cooled tank. I'm not sure that a tank's worth of air contains sufficient mass (and associated lack of heat) to cause bodily heat loss sufficient to cause compensatory increased air consumption. If you are warm, your body should behave as if it is warm, all other things being equal. If you are not warm, the situation changes dramatically. A least, that is how it seems to me.