# Find Approximate BTU of Air in 10 Cubic ft of 95F Water

• Denys.Ca
In summary: I can't apply any of the approximate calculations, because I don't have the data.The first heat source is a electric heater that is on the opposite side of the tank from the water. The second is a wood burning stove in the room next to the tank. The third is the sun.In summary, Russ was trying to find the BTU of air to heat up a tank of water to 95 degrees Fahrenheit. He needed to find the initial enthalpy of the air, and the equilibrium temperature of the water and air.
Denys.Ca
I've got 10 Cubic ft of water at 95F.

I'm agitating it with air at 15psi, with 65F temperature.

How can I find the BTU of air? Approximately.

Last edited:
The question is incomplete - the sentence appears to be missing some words. Could you try again please?

lol =)))

I realize to solve this I will need some additional numbers.
This isn't a question from the book russ, that's what I've got. Tell me what's missing, I'll get it.

The phrase "btu of air" has no meaning. Perhaps you are looking for the btu added to or taken away from the air? Or the enthalpy of the air?

You are right. I do need to find enthalpy of the air

Are we waiting for an equilibrium or just looking for the initial enthalpy of the air after it leaves the water? Is the container insulated? Covered? Pressurized? Is that gauge or atmospheric pressure?

Is this homework?

This is just a project at the plant I'm at.

I'm looking for the initial enthalpy.
The container is open and under atmospheric pressure

Ok, well a host of assumptions are required here, but basically the water will warm up the air to its temperature and evaporate into the air, making it saturated. You should be able to plug that into a steam table to find the enthalpy.

Now that You've said it, I do look for the equilibrium. The end result is to bring down the temperature of the 10 cu ft tank down.

Although, I see that it would be even quiet hard to come up with the approximate results, that I can apply, because there are too many unknowns. I have three heat sources and I don't have the heat exchange rate for them. All I have is the current temperature of the tank, psi of air entering, and it's temp.

## 1. How do I calculate the approximate BTU of air in 10 cubic ft of 95F water?

To calculate the approximate BTU (British Thermal Unit) of air in 10 cubic ft of 95F water, you will need to use the following formula: BTU = (cubic ft of water) x (specific heat of water) x (temperature change in Fahrenheit). In this case, the specific heat of water is 1 BTU/lb°F, and the temperature change is 95F (since the starting temperature is 95F). So, the calculation would be: BTU = (10 cubic ft) x (1 BTU/lb°F) x (95F) = 950 BTU.

## 2. What is the specific heat of water?

The specific heat of water is the amount of heat required to raise the temperature of 1 pound of water by 1 degree Fahrenheit. It is typically measured in BTU (British Thermal Units) per pound per degree Fahrenheit (BTU/lb°F). In this case, the specific heat of water is 1 BTU/lb°F.

## 3. Why is it important to find the approximate BTU of air in 10 cubic ft of 95F water?

Knowing the approximate BTU of air in a certain volume of water is important for various reasons. It can help with determining the amount of energy needed to heat or cool the water, which is useful for industrial processes and HVAC systems. It can also be used to estimate the amount of heat that will be transferred from the water to the surrounding air.

## 4. Can I use this formula for different volumes and temperatures of water?

Yes, the formula can be used for different volumes and temperatures of water. Just make sure to use the correct units for volume (cubic ft) and temperature (Fahrenheit) and to check the specific heat of the specific type of water you are using.

## 5. How accurate is the calculated approximate BTU of air in 10 cubic ft of 95F water?

The calculated approximate BTU of air will be fairly accurate, but it may vary slightly due to factors such as the type of water being used and any heat loss during the transfer process. It is always best to double-check your calculations and consider any potential variables that may affect the accuracy.

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