Use a 110v relay and a floor mat to create switch your dog can use to turn a fan on/off at their own desire/need.

Our dog breed of preference is the Alaskan Malamute. When we lived in Seattle our Malamutes loved the weather so we seldom had need for "extra cooling" for them. Then a job change later, we moved to Texas! Here in Austin we have a bit more temperate weather than DFW or Houston, but it's Tejas still! So, we realized that while being inside in the Air Conditioning and having a dog door was a requirement for the dogs, we also realized that they might want/need more cooling... so, we found a big powerful fan that moves a LOT of air! This fan sits on the ground which will allow the dog to lay in front of it and cool down more. Problem is, the dogs want to be where you are, and the fan is NOISY! Having it run 24/7 isn't an option. So we were having to turn the fan on/off/on/off/on/off (any dog owners who have upgraded to a dog door know JUST how demanding a dog can be once they learn how to operate you as their remove control!) got old FAST!

After far too long/eventually I realized, this problem has been solved! I just need to adapt it to our needs! So, I ordered a 110v relay, picked up some supplies at the hardware and art supplies store, rummaged around through my electronics, and built a floor mat 110v relay powered Dog Fan switch!

Step 1: Gather the Supplies

Supplies you will need:

Control Box:

110v AC / 12v DC Relay

Examples:
http://www.radioshack.com/product/index.jsp?productId=2049721&CAWELAID=37889620
http://www.mcmaster.com/#69585K87

12v DC Wall Wart
6 or 7" (or larger) Electrical Junction Box (large enough to hold old work box(es), wall wart, and relay)
1-Gang "old work" switch/outlet box
One 15A 110v Power Outlet
One 1-Gang Outlet Cover
110v Power Pigtail
10' of "Light Cord" power cord
Soldering Iron / Solder (and Flux)

Optional additions to enable bypass control:

One or Two light switches to disable floor mat and/or relay bypass
One 1-Gang Light Switch Cover
Second 1-Gang "old work" switch/outlet box if you wish to add light switches to enable control of power outlet to bypass or disable the floor mat

Floor Mat:

2 pieces of 2' square (minimum) cardboard mount board or some other stiff and non-conductive material.
Aluminum Tape
Foam Door Gasket
Packing Tape

Step 2: Build Control Box

Take your electrical box, and cut out the openings for the Old Work receptacle boxes on each side Be sure to check for room for all of the components (relay, wall wart, and wires) in addition to the switch covers in relation to the lid when laying out where to cut these openings!!!

Drill holes for the 110v AC power in and the 12v DC out. Be sure to try and closely match your holes for the wire to your wire size. I removed a power connection from an old/dead PC power supply by opening the power supply and unscrewing / desoldering it and installing it into the main control box so I could use PC Power supply power cords for my AC in connection.

Be SURE you are routing the 12v DC through the floor pad and NOT the 110v AC! We don't want to see you electrocute your pooch after all. :)

If adding the optional power/light switches, you'll need to also wire those up (some knowledge of how to wire these up will be required and is an advanced configuration)

Solder your 110v AC in up to your relay. A schematic should be imprinted on the relay itself, but if in doubt break out the multimeter with continuity tester and verify / identify what each of the 8 terminals are. Most likely you will want to connect to third row of pins. You can test your relay also by connecting the 12v DC wire ends / leads to the relay's vertical terminals. You should see the relay make the connection/disconnect as you apply / remove the 12v DC.

Step 3: Build Floor Mat

To create the floor mat you will be using the cardboard squares and applying the aluminum tape in strips across one side of each. Overlap the tape on each so you have complete coverage.

Test for continuity across the strips of aluminum tape. You MAY find that your tape has enough glue on it that you don't have continuity across each strip. An easy way to fix this is to run a cross strip of aluminum tape, or take a 1" x 1' piece aluminum foil and lay it across the strips and tape it down, or perhaps by laying a strip of copper wire across the strips and tape that down. So long as you have continuity from any one point to any other point on the mat, you'll be good!

Run the 12v DC wire out through the hole in the control box, leaving the wall wart with space inside the box to reside inside it between (or behind) the electrical receptacle.

Connect the 12v DC wire ends to your mats. Strip 3-4" of wire off of the wall wart (after you cut off the existing connection) and tape it down with the aluminum tape. You may want to tie a small knot on each end to keep it from being possibly easily pulled out from the tape if the tape adhesion isn't very good.

You may need to add a small piece of the foam into the center to help keep the two sides apart depending on the stiffness of your cardboard and weight of your dog. The heavier the dog, the more likely you WILL want this as after a month or three you will notice when the dog gets up, the fan doesn't shut off quickly or at all anymore, necessitating the spacer. This is an EASY post construction fix to make however, as you only need to cut a little tape to regain access to the insides of the mat.

Lay down the door foam insulation across the four sides of one of the

Check your continuity again one last time, then tape your two sides together, aluminum tape facing towards each other.

Step 4: Test

Once you have the control box wired up, and the floor mat connected, it's time to test...!Plug in the fan to the power receptacle, plug in the 110v AC into the control box, and press down on /step on the floor mat. The fan should turn on. Step off / release pressure, the fan should turn off.Toss a towel or dog bed onto the top of the mat, and wait to see how the pup reacts to it.Our female Malamute took took a few days to get used to "this thing" in front of her fan... but now she uses it without issue or question. :)