Ideas for a school demo

[Wheelbaron]

So next month I'm going to my kids school for "what I do for work". Trying to think of a cool but easy demo for air conditioning, or maybe radiant heat....

I have lots of stuff laying around to work with, but it has to be something small and easy to demonstrate. (7&8 grades)

[defhvacr]

Find a small 115 volt refer condenser and evaporator and make your self a little demo. Use red and blue paint to represent high and low pressures. The evap can be mounted on a sheet metal plate above the condenser. Take a lable maker and lable the parts.

[Tech it out]

Use a sponge and 2 buckets. Label one bucket indoor the other outdoor. Put water in the indoor bucket and transfer it to the outdoor bucket. Take along some old A/C parts for show and tell. :grin2:

[timebuilder]

Draw the school building on the board. A simple one.

Show the AC unit on the roof. Blazing sun coming down on the building.

Stick figures of students in the window.

Now, explain that the machine on the roof moves the heat out of the place where the students are, and gives it back to the atmosphere "where it belongs."

Explain that ALL heat we have comes from the Sun. We just move it around. Explain that heat is trapped in atoms, coal, gas, and oil. And, the Sun has been changing our planet's environment for centuries, both hotter AND cooler.

The heat can be used for many great things once it is released, but we have to manage the heat by moving it to different places, so that we are comfortable and healthy.

HVAC is the science of releasing and moving heat so that we have a better, more comfortable environment.

Now, you hit the keywords that they will be exposed to in their other classes

[garyed]

Make a simple working layout using light bulbs for each component of the system. Take a piece of plywood, attach whatever relays, contactors, transformer, t-stat, etc. Activate them to turn the bulbs on for each part of the system. Make sure to use a 120v. transformer so you can just plug it in to any receptacle.

[Wheelbaron]

All good ones, especially the sponge in buckets, lol

I do have a small under counter Bev Air freezer that I need to get around to fixing. I could repair it and leave all the covers off the evap and bring it in with a bunch of labels on it.

Need to throw a new pump in it, works fine but starting to ground through the windings so it pops the GFI outlets every time.

[knave]

take a vacuum pump and a pint jar, and boil water for them at room temp. If you only put 3/4" of water in, it will freeze in a matter of minutes. I just did it in our meeting this morning.

I know it doesn't show a system, but it does show how they work, and is fun.

[keeplearnin]

Lock all of the kids in the walk in freezer and tell them what they are about to experience is heat transfer.

[maxster]

#14 turbo tip and B tank :gah: that will get their attention.block of ice and as you explain why it is melting they touch it and say how it is air conditioning the room as it melts.

[R Mannino]

Live fire an oil burner.............school administration might have a problem with that.

http://www.youtube.com/watch?v=OlgpDo1Yv_w

[sweat hog]

Im thinking transfering refer from one tank to another using the needle valves on the manifold to frost the hose. A sight glass and small compressor would add to the fun.