Common heat issues : some insite :)

[jansenwrasse]

I see a ton of folks having trouble with temps (especially high). I am hoping to maybe shed some cool light on the subject! I will try not to get to un depth but enough to get the point across

First the heat!

Heat is basically the movement of atoms and molecules as energy is added heat is created. The hotter something is the faster the molecules/atoms are moving. Absolute zero is the theoretical temperature where molecules cease to move and there is no heat energy exists.

Humidity:

There are several measurements of humidity and they can get involved.
1) Humidity : ammount of water vapor in the air.
2) Relative Humidity(R.H.)The ammount of water vapor in a container as compared to the ammount of water that the the conatiner can hold (before precipitation) at a given temperature. This is what we hear most commonly in New York from our local weather person. 100% means the it is precipitating (Raining).

In bootcamp we used to have to (as "punishment") have to do exercizes until it "rained". I had no Idea what this meant until the water dropples would form on the ceilings and walls and literally Rain down on us!! aah the good ol' days! 100% RH Indoors!

I will break this into several posts!

 

[Conesus_Kid]

I'm looking forward to reading more. If you have any numbers crunched to show if/why/how an AC unit is better than a chiller, I would be most appreciative!!!

Thanks!

 

[jansenwrasse]

Now Cooling!

Now Cooling!

Cooling is an area that gets really confusing!

Cooling is basically slowing down atoms/molecules.

Convective cooling:

HVAC guys are masters at this type of cooling. It is the cooling by forcing Cooler air into an environment. In our cases it is usually over a warmer body of water. Convective cooling is very efficient and cost a ton less to do if there are a few things that can be maintained (later post).

Conductive cooling:

This is a prime example of your common chiller. Water passes over (in dirrect contact with) a (usually) titanium coil that is kept very cold with the use of pressurized freon. The warmer water warms the freon and then the heat is "blown off" by the depressurized Freon (ever felt the heat comming of the back of a running air conditioner?). (please note that the term "freon" is only used as a generic name for a refrigerant and is not all inclusive)

Temperature is next

 

[jansenwrasse]

Temperature:

Temp is a measure of heat. There are several scales used Fahrenheit , Celsius, and Kelvin are the most common. For our purpose we will use "F". (at sea level) water boils at 212F and freezes at 32.

If you want to convert between any of them here are the formulas:

even better wiki has a chart that is correct (this time )
http://en.wikipedia.org/wiki/Temperature_conversion

Wet and Dry bulb temperatures... wait what temperature?

Humidity plays a HUGE role in convective cooling, ever tried cooling off with a fan on a 100F day when its raining? If not I can assure you it doesn't work well! Here is why! this gets kinda hazy (no pun intended)

Dry bulb: The temperature of an air sample that the thermometer is protected from the moisture in the air.
Water vapor in the air could cool or warm a thermometer if the air were to pass over it ( kinda like wind chill)

Now the dreaded wet bulb temp!
The wet bulb for our purpose that we are concerned with is the temperature of the real air we and our tanks are in. It is a measure of temperature with humidity.

If the wet bulb temperature is the same as the tank temperature there can be NO, NONE, NADA cooling performed by convective measures.

Sumin it up

 

[jansenwrasse]

Above is why an AC unit works. Maybe not better but it works.

**EDITED**

Spelling error (one of the many)

 

[Paradiddle7]

You don't need numbers, just some common sense.

It's impossible to get energy from nothing and to make energy disappear. Think of cooling devices as heat exchangers. The amount of cooling that is going on is also the same amount of heating that is going on somewhere else in the same system. If you have your chiller inside your house, then you are effectively exhanging the heat from your tank into the air of your house. Air conditioners are outside your house or vented outside in the case of portable or window units. If they weren't then they wouldn't be making your house any cooler. Now, look at the expense of aquiring an aquarium chiller; IMO they are VERY expsensive compared to units made for the home. Then you have to consider the cost of running your chiller PLUS the added cost of having to run your home's AC to compensate for the heat that your chiller is giving off.

IMO, a chiller should only be used as a last resort emergency to prevent your tank from overheating. It's much easier and IMO, cheaper to just run your home's AC. The most ideal setup, IMO, is to setup a sealed fish room (behind your in wall tank), and have it's own window AC unit to keep the temp of the fish room at ideal levels.

When I had my 12g nano tank, I had an ice-probe chiller in my sump to compensate the amount of heat my 70w MH was adding to the system. It was really just buying me time so that the final temp of the tank wasn't too high by the time the lights went off.

<a href=showthread.php?s=&postid=12701331#post12701331 target=_blank>Originally posted</a> by Conesus_Kid
I'm looking forward to reading more. If you have any numbers crunched to show if/why/how an AC unit is better than a chiller, I would be most appreciative!!!

Thanks!

 

[Namyar]

Very usfull information JW

 

[Conesus_Kid]

Gotcha!

 

[jansenwrasse]

So here is the trick to cooling a tank on that blistering hot day.

1) get the wet bulb temperature BELOW the temperature of the tank. Go to you local store and pick up a nice air conditioner to lower the physical temperature of the ambient air.

2) Get a nice box fan and blow this nice cool air over the largest open surface of water. Please don't place a box fan on the tank you are asking for trouble

3) KEEP THE TANK COOL. It is much easier to maintain then to have to catch up to a warm tank.

Consius kid brought up a good point.

here is what a Chiller does:

The heat taken from the tank and into the freon is blown off into the ambient environment (as discussed). If that ambient environment is the one with the tank in it you are heating that room to an unbelieveable temperature. By doing so guess what you have raised the wet bulb temp, and made that room not fun to hang out in! If the chiller is vented elsewhere (outside) then the process is eliminated and the chiller works very well.

When the wet bulb temp rises the ambient environment is going to heat the tank, not cool it. So the chiller is cooling the water and heating the environment and the environment is heating the water, and RG&E wins every time!

I hope this was helpful and good luck this summer!

 

[jansenwrasse]

Man you guys either type super fast or I am super slow!

 

[thriceanangel]

I'm looking for some info on Specific heat and how that plays a part, seem pertinent in the AC question...

Some other questions:

Heat= IR... True or false?

Lighting effects on heat of the tank ie, if I cut my light cycle by an hours, how much heat build up will I lose?

My basement is cool but very humid... will I need to put AC in it?

 

[thriceanangel]

.

 

[EllieSuz]

When the thunder storm rolled through last night and the lights flickered, I was struck that there is no way to hook up the central air to my generator. So, in the event of a power outage, what can be done?

 

[thriceanangel]

Seem like that first calorimitry lab is getting more useful!?

 

[jansenwrasse]

<a href=showthread.php?s=&postid=12701572#post12701572 target=_blank>Originally posted</a> by thriceanangel
I'm looking for some info on Specific heat and how that plays a part, seem pertinent in the AC question...

Some other questions:

Heat= IR... True or false?

Lighting effects on heat of the tank ie, if I cut my light cycle by an hours, how much heat build up will I lose?

My basement is cool but very humid... will I need to put AC in it?

Lights do add radiant heat to tanks as to the environment. As to the actual mathematics behind the heat not added there are so many variables. Ambient temps, Humidity, Bulb wattage, Air flow, Atmospheric pressure, Volume of water.

The best thing to so would be to turn off everything in the tank. Measure temps, and humidity. Then track the temps and humidity in air and the temp of the water. From there I would add about 5% error with wate circulating and pumps. Sorry I couldn't be of more help on this one.


Suz: The best thing personally would be to start lowering the tank temp as much as possible immediately. It would be a chore as no electricity to run fans, but here is what I would do. Close all doors and windows, prepare for a cold water change. Have ready to go (in the basement or some where cool) a 30% water volume change ready to go. If there is no where to keep water cool then read this:
How to Mix a Batch of Synthetic Seawater in Under Five Minutes
http://web.archive.org/web/20011217...bio/default.asp
Again a tall order with out electricity but battery opperated air pumps in upstate New York is almost a MUST! Winter Ice storms, Eastern sea board power grid failures...

 

[redrider911]

Re: Now Cooling!

Re: Now Cooling!

<a href=showthread.php?s=&postid=12701352#post12701352 target=_blank>Originally posted</a> by jansenwrasse
Cooling is an area that gets really confusing!

Cooling is basically slowing down atoms/molecules.

Convective cooling:

HVAC guys are masters at this type of cooling. It is the cooling by forcing Cooler air into an environment. In our cases it is usually over a warmer body of water. Convective cooling is very efficient and cost a ton less to do if there are a few things that can be maintained (later post).

Conductive cooling:

This is a prime example of your common chiller. Water passes over (in dirrect contact with) a (usually) titanium coil that is kept very cold with the use of pressurized freon. The warmer water warms the freon and then the heat is "blown off" by the depressurized Freon (ever felt the heat comming of the back of a running air conditioner?). (please note that the term "freon" is only used as a generic name for a refrigerant and is not all inclusive)

Temperature is next

We don't force cooler air, we remove heat. If you want to get technical. And in your terms it would be conductive cooling because warm air is passing through a cold coil.

 

[Conesus_Kid]

<a href=showthread.php?s=&postid=12701572#post12701572 target=_blank>Originally posted</a> by thriceanangel


My basement is cool but very humid... will I need to put AC in it?

A coupla things I do know:

If your basement's humid, you will have a tough time cooling your tanks w/ fans (evaporative cooling).

An AC unit takes air from the outside, removes the heat from it (and thereby lowers its humidity since cool air can hold less moisture than warm air) and exchanges it for the warm air inside the dwelling. That is why window and automobile AC units drip water (it's condensation).

From my standpoint, an AC unit combined with fans to assist in evaporative cooling can be an effective method to keep tank temperatures down.

I've been debating a chiller for the school tank, but since there is no AC at school, my best bet may be a portable AC unit in the sump room vented through the ceiling with some fans blowing across the sump. A chiller would just blow hot air in the room without removing any heat from the environment.

My other alternative is to run a chiller and exhaust the heat through the ceiling. I'm guessing that the kids would prefer the AC!!

 

[jansenwrasse]

Missed one

Basement is cool but humid:

Convective cooling will still work assuming that there is room in the environment for more humidity.

 

[jansenwrasse]

Remember heat rises and cool settles. Heat also moves from hot to colder.

 

[EllieSuz]

Thanks, Jensen, but since I have a generator, winter power outages are no problem and I can run fans in the summer with the generator, but not the central air. You've given me some good ideas and I appreciate your input.