Does cold water increase air consumption?

[lmorin]

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.

 

[SteveAD]

It's not cold water, so much as being cold that will increase air consumption. 45 degrees in a drysuit I'm nice and relaxed, 65 in a 3mm I'll be huffin and puffin like a choo choo train.

 

[haha49]

well in cold watter your air compsuption rises do too the fact your body must do more too keep warm ie you shiver to warm up doing so makes for more pyshical work meaning that you use more air as your body needs more oxygen so it can work fully to keep you warm.. theres that and more weight and gear meaning you have more to carry around more drag ect.. doesnt help eather..

 

[all4scuba05]

It's not cold water, so much as being cold that will increase air consumption. 45 degrees in a drysuit I'm nice and relaxed, 65 in a 3mm I'll be huffin and puffin like a choo choo train.

Totally agree with you and the Cpt.
Cold water doesn't increase your breathing...a cold body increases it. Dress appropriately for the dive. No reason why you should be cold already on the first dive. Sucks when you don't dive dry, don't it?

 

[String]

Cold water doesn't increase air consumption - BEING cold does.

You can be colder in a wetsuit in 20c water than a drysuit in 6c water and use more air in the warmer water as a result.

Carrying more weight generally increases SAC too and generally the colder the water the thicker the suits and more weight. This effetct is a lot less than the first though.

Example from my logs, my SAC was 40% higher with a 5mm wetsuit in 20c water in Malta than it was in 6c water and my drysuit last week. The difference purely is in the 5mm wetsuit i was frozen to the point of shaking but in the drysuit i was comfortably warm.

 

[fisherdvm]

Animals eats more in cold weather to keep warm. We burn more calories to keep warm. This uses oxygen.

Second, cold water causes neoprene to stretch less, and the more bulk you wear, the more it restrict yor tidal volume. Smaller tidal volume equals more dead space ventilation - and you use more air.

Third, more lead, more mass - to get from point A to B, you have to fin harder - and burn more air. More mass equals more work.

 

[TSandM]

It's interesting that it's said that cold water increases consumption, and anecdotally a lot of people report it, but I see very little reliable difference in my own gas consumption between cold and warm water.

 

[Lehmann108]

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.

 

[String]

Second, cold water causes neoprene to stretch less, and the more bulk you wear, the more it restrict yor tidal volume. Smaller tidal volume equals more dead space ventilation - and you use more air.

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

Third, more lead, more mass - to get from point A to B, you have to fin harder - and burn more air. More mass equals more work.

That is the only part thats true.

 

[String]

It's interesting that it's said that cold water increases consumption, and anecdotally a lot of people report it, but I see very little reliable difference in my own gas consumption between cold and warm water.

Its very noticeable here with me. Even when im warm on a dive. Cold water/uk diving my SAC is around 15-16litres/minute. Warm water diving its 11-12 litres/minute. Its more likely due to the added mass and bulk of suit and lead than anything else.