B Energy transfer water > air in a greenhouse

[SpitfireIX]

How did you find PF?: google

New here. As someone who stopped studying physics and mathematics many decades ago at the age of 16, I don't have much recollection of what I studied. I would appreciate any guidance offered on how to calculate a couple of things, please.

This problem relates to warming air in a greenhouse in winter using water at a higher temperature than the air in the greenhouse

Given:

100 kg of water in a container (tank etc)
10 cubic metres of air in a greenhouse

What formula is used to calculate the energy required to raise the temperature of 100 kg of water by 1C?

What formula is used to calculate the energy required to raise the temperature of 10 cubic metres of air by 1C?

Any advice on how to calculate energy transfer from the air in the greenhouse to the air at a lower temperature outside via its glass panels would be welcome.

Thanks for any answer.

 

[PeroK]

You need the specific heat capacity of air and water. And also to calculate the mass of something based on its volume you need its density.

 

[SpitfireIX]

Thanks for your reply.

 

[TensorCalculus]

!
If you're still struggling (though PeroK has given you some very good guidance), do post this question (and any other questions you may have) here. Just make sure to show you attempted it first as well :)

 

[gmax137]

Any advice on how to calculate energy transfer from the air in the greenhouse to the air at a lower temperature outside via its glass panels would be welcome.

This can be a rather complicated problem to work out from first principles. I would start by looking for technical info from greenhouse manufacturers. They would have worked out the details using appropriate assumptions or simplifications, or even using test data from real greenhouses.

 

[russ_watters]

100 kg of water in a container (tank etc)
10 cubic metres of air in a greenhouse

Can you please provide more information:

• What is the tank made of?
• Is the tank open or closed?
• What else is the tank for (why have/use a tank?)?
• How is the water being heated?
• What is the outdoor air temperature and indoor temperature?
• What is the greenhouse made of ?

What formula is used to calculate the energy required to raise the temperature of 100 kg of water by 1C?

What formula is used to calculate the energy required to raise the temperature of 10 cubic metres of air by 1C?

The answer to both is the specific heat capacity times mass times temperature change. But that's not actually what this problem is about. This is a heat transfer problem, and as said it may be very difficult to determine analytically. But maybe there's a shortcut: Does the greenhouse currently have a heater?