The Haunt Air Manager is a standard component used for pneumatic effects in our haunt. In one package, it provides electrical triggering, pressure regulation, exhaust regulation, and air storage.

• Why bother?
• A little slice of HAM
• Green Eggs and HAM
• Bits and pieces
• Valves

• Related Pages

But there is one additional problem. Let's consider a little thought experiment...

Think of a toy balloon as your air-activated prop. Just imagine the balloon painted with a monster face, and inflating it causes the monster to suddenly appear in front of the trick-or-treaters.

You connect the balloon to a compressor and a valve that can be used to send air into the balloon on command. Kids come up the walkway; you open the valve; air flows into the balloon, making it expand; kids run away in terror.

Now what?

I mean, now, how do you prepare for the next batch of kids? You have to let the air out of the balloon. This allows the balloon to deflate, resetting the scare for the next batch of kids.

But we didn't plan for that! All we have is a way to get air into the balloon. If we open the valve again, even more air will go into the balloon. We need a way to exhaust the air. There are numerous ways to do this. We will use Three-Way Valve Method.

A little slice of HAM

This is the simple version of the Haunt Air Manager unit. It features:

• quick snap-on air connectors on both ends
• pressure regulator turns the incoming high-pressure feed into precisely controlled pressure that this particular effect needs
• electrically-activated air valve dispenses air on command
• flow regulator on the valve's exhaust port controls the rate at which the effect returns to the quiescent state

It's really quite simple.

Here's a list of parts for the little slice of HAM. Prices and part numbers are from my local Harbor Freight Tools, circa September 2001.

quantity	part	part number	unit price
1	1/4" brass industrial-style quick-connect male
1	1/4" brass industrial-style quick-connect female
1	3-way solenoid valve, with 1/4" NPT ports
1	diaphragm pressure regulator, with 1/4" NPT ports	#32872	$9.99
1	flow regulator, 1/4" NPT	#32905	$2.99
1	AC line cord set
1	fuse holder, inline
1	fuse
~2	1/4" connectors (close nipples)

Green Eggs and HAM

This is the upscale Haunt Air Manager unit. It features:

• quick snap-on air connectors on both ends
• provides local storage of compressed air: as you add effects, you add air storage
• pressure regulator turns the incoming high-pressure feed into precisely controlled pressure that this particular effect needs
• electrically-activated air valve dispenses air on command
• flow regulator on the valve's exhaust port controls the rate at which the effect returns to the quiescent state

Here's a list of parts for the Green Eggs and HAM. Prices and part numbers are from my local Harbor Freight Tools, circa September 2001.

quantity	part	part number	unit price
1	1/4" brass industrial-style quick-connect male
1	1/4" brass industrial-style quick-connect female
1	3-way solenoid valve, with 1/4" NPT ports
1	diaphragm pressure regulator, with 1/4" NPT ports	#32872	$9.99
1	flow regulator, 1/4" NPT	#32905	$2.99
1	AC line cord set
1	fuse holder, inline
1	fuse
~3	1/4" connectors (close nipples)
1	converted propane tank (cleaned, drilled, and tapped)
1	tee, 1/4" NPT
1	pipe nipple, 1/4" NPT
1	street elbow, 1/4" NPT

[This particular sample used, instead of a street elbow, a regular elbow and yet another connector. Use what you have, can scrounge, or buy for cheap.]

Bits and pieces

Here are close-ups of some of the pieces that go into the various HAM variations.

Improvised air tank

With a full order of HAM, you get Green Egg, the air storage tank made from a recycled propane tank. The compressor makes all the pressurized air that we need, but might be tempted to run its motor all night long. In order to keep the motor from running, we provide air storage tanks. The motor runs only until the storage tanks are filled, then shuts off until the storage tanks run low again. Larger compressors have storage tanks of their own, and you can easily add more air storage with additional external tanks.

We have elected to give each air-powered haunt effect a little air storage of its own; as you add props, you add air storage to operate them.

Construction is simple: get empty propane tank; make sure it's empty; unscrew and remove the two valves; wash out with soap and water; drill and tap for 1/4-inch NPT; clean; paint; replace the pressure-relief valve. (detailed instructions)

Quick connectors

Note - This comes at a slight cost in system operational efficiency, because hard connections leak a bit less than the quick connectors.

Solenoid valve

Solenoid valves come in all brands, sizes, and ratings. This one is an ASCO Red Hat model. The complete HAM unit shown at the top of this page uses a Mac valve.

Other pieces

• manifold - This is a T-shaped connector that allows us to take the air coming in from the compressor and route it to both the local storage tank and the solenoid valve.
• pressure regulator - This allows us to run the compressor at high pressure, and each prop at a lower pressure that is no more or less than the prop needs.
• flow regulator - This controls the speed at which air escapes from the prop after you turn off the solenoid valve. This lets you control the speed at which the prop "resets" for the next scare.
• assorted 1/4-inch NPT fittings

Then, just put it all together with Teflon plumbing tape.

But these are two-way valves, with no provisions for the exhaust that allows your prop to reset. You will have to install a bleeder valve, and live with the wasted air that results.

I don't know of any commonly scrapped consumer item that will yield three-way valves for free. Your choices are to buy them new, or find used ones from dealers in surplus stuff.

One good point is that you need not be constrained by any particular make and model number. Good, usable valves from a variety of manufacturers pop up surplus all the time. Just make sure they:

• are three-way valves, with three connection "ports"

• have input and output ports that you can attach to

  We like 1/4" NPT, but you might like something else.

• take a power supply that you can deal with

  We like 110 VAC because it is easily driven by X-10.

• can take the pressures that you will be dealing with

  If the solenoid valve is connected straight to the compressor, read the compressor documentation and make sure that the valve is rated for at least the maximum pressure that the compressor puts out. If you have a pressure regulator between the compressor and the valve, make sure you never turn the pressure up past what the valve can take.

• have an oriface capable of handling sufficient air flow

  This is seldom a problem unless you have a prop that needs a lot of air, fast. 1/8" seems adequate for most applications.

Here are some valves that we have used:

MAC 113B-111BAAA

ASCO "Red-Hat" EF8003G1

(only rated for 50 PSI)

We have more info on solenoid valves, including information on different types, how they are used, and where to find them.

• Connecting Solenoid Valve To Pneumatic Cylinders
• Haunt Air Manager (HAM) [this page]
• information on solenoid valves
• pneumatic cylinders

Thank you for visiting. Your comments are welcome.
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