Tank Temperature Question

[jibboo]

ok, my question is, if I have a tank without a heater ... why isn't the water stabilized at room temperature?

My room/house is set at 77 F ... which I imagine the room with the tank is in is actually hotter since it is my office with little ventilation and 2 computers running (which makes it feel hot to me). BUT, my 1 gallon tank is sitting at 70-72 F. The thermometer could be off I suppose, but when I touch the water, it feels cold to me.

So, am I'm losing my mind or this some strange scientific phenomenon that I'm not understanding. I know water changes temperature much slower than air, but I've had this up and running for about 3 weeks. Any ideas?

 

[Bhunsucker]

I'm not real sure what it wouldnt be RM Temp. but your body temp is 98.6 (average) so 77 is going to feel cold to you.

 

[jibboo]

true, 77 is cold compared to 98.6 ... but I can feel the room temperature and the water feels colder than the air to me ... or maybe that's a normal feeling.

 

[BillD]

The water will always feel cooler than the air, if it is the same temperature. Evaporation from the tank may be a factor in keeping it cooler than the room, but it should stabilize to room temp. You are right that it will cool more slowly and warm more slowly than the air in the room, but it will try to match the temp.

 

[TomK2]

Water always feels colder than air ,due to the differing "specific heat" of the two substances. Water has a much higher specific heat than air, meaning Water holds or robs way more heat from you than air. One example, an oven at 350 degress with your pizza in it. Go ahead, reach in the oven and take it out, your arms won't get burned. Now take your stove with a pot of boiling water at 212 degrees. Stick your arm in that and you have a serious burn in microseconds. The Hotter oven air doesn't hold as much energy or heat as the less hot boiling water.

Take your freexer at say, 28 degrees. Reach in and grab that frozen pizza, dig around, spend a half an hour deciding which one, no problem. Now stick your arm in 40 degree water, and it goes numb in seconds.

Make sense?

 

[jibboo]

OK, so with all of that ... is my thermometer off?

if I take the thermometer out of the tank ... will it work for measuring the temperature in the air?

I guess this really isn't a big deal, but I am curious as to why this all is.

 

[TomK2]

Possibly. Is there an air conditioning duct near the tank, allowing cool air to get at the tank?

I have an unheated 55 gallon tank. I have a room thermometer that says 70 degrees. The tank reads 75. I moved the tank thermometer into another tank to compare readings with a second tank thermometer. They were the same. So I conclude that the room thermometer is different than the tank thermometers. I took the tank thermometer and put it right next to the room thermometer to measure the air. Room thermometer reads 70, tank thermometer reading of air is 75.

The room "feels" cool to me, so I would agree with the 70 degrees. But does that mean my two tank thermometers are off?

 

[jibboo]

well, I took the tank thermometer out of the tank at my last post (6:52pm) and now (10pm) the tank thermometer is reading an air temperature of 74F ... so it went up 2-4 degrees. i'll check it again in the morning and the try it again in the tank and see what the temps read.

 

[Kizayaen]

Keep in mind that water is a (low-grade) refrigerant. Meaning, that as it evaporates, it absorbs heat. Since the surface of your tank should constantly have water evaporating, even at a very slow rate, it stands to reason that it'd be a bit cooler than the ambient temperature.

 

[jrp1588]

My tank is actually warmer than room temp without a heater.

 

[Kizayaen]

Guess that blows my theory to hell.