ResMed Air Sense 10 Air Blowing Cold

[Viraj3474]

Awoke this morning at usual time with air blowing cold and nasal passages feeling very irritated. I noticed that the humidifier water tub was empty, used up. My question is does this machine sense water is gone and shut off the heat for the water tub? Or does the air just blow a lot colder without water in the tub? I decided to test it and added water to the tub and see what happened. Much to my relief the machine started blowing warmed air and may not be broke as I assumed. Sure would appreciate your take and any information on this.

[ChicagoGranny]

1. Humid air is warmer than dry air.

2. ResMed has no heat shutoff for an empty humidifier tank.

https://ap.resmed.com/knowledge/what-ha ... t-of-water

[LSAT]

The air the machine blows is your room air. It would be the same temp. as the air you are breathing in your room. It is the moist air from the humidifier that warms the air you breathe. If you run out of water, the machine cannot produce humidity and you are back to the temp. of your room.

[Conrad]

1. Humid air is warmer than dry air.

2. ResMed has no heat shutoff for an empty humidifier tank.

https://ap.resmed.com/knowledge/what-ha ... t-of-water

Humid air is warmer than dry air? How's that work? Can they not both be the same temp?

Sorry, that makes no sense at all.

Humid air is more humid than dry air, that's the only fact here. They can both be the same temp, or different. Humid air isn't inherently warmer than dry air.

[ChicagoGranny]

Sorry, that makes no sense at all.

Don't overlook the context. The water vapor carries the heat to the nasal passages more effectively than room air.

[Dog Slobber]

Sorry, that makes no sense at all.

Don't overlook the context. The water vapor carries the heat to the nasal passages more effectively than room air.

Yes.

And probably more importantly (and in context), humans do a poor job of judging temperature, what we feel is heat transfer, the ability to transfer heat from our bodies, or to our bodies. The difference may seem subtle, but it's not.

This becomes obvious when comparing two objects that are identical in temperature but have two very different heat conductivity rates.

Put a block of wood and a metal item on your counter long enough for them to reach room temperature. They both will be identical temperature. But, touching the metal item will be much cooler than the wooden one. We don't feel the temperature of the items, but the heat transfer, and the metal item draws much more heat from us.

Less humid air may be at the same temperature as humid air, but it feels a lot cooler because the drier air draws more heat from our passages.

We also see this phenomenon when people believe their heated hose isn't working because their hose doesn't "feel" warm. Their hoses don't feel very warm because the plastic tube is not a very good heat conductor.

[zonker]

And probably more importantly (and in context), humans do a poor job of judging temperature, what we feel is heat transfer, the ability to transfer heat from our bodies, or to our bodies.

thank you for this wonderful explanation.

have you ever considered teaching?

(ducks,runs)

[Viraj3474]

Well! Thanks to all here as this is clarifies what I experienced. The air blowing out of the my cpap hose was probably around 68 degrees as we have our heat set down cooler for better sleeping. I increased the water in the humidifier tank and the effect was comfortable once more. Nothing wrong with my aging cpap that adding a little more water didn’t fix.

[Conrad]

Yes, humid air FEELS warmer, subjectively, than dry air at the same temperature.

Thus

Damn it's so hot! True, but it's a dry heat...

lol