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Picture of Kill Bedbugs in your luggage
Do you stay in hotels a lot?

Will you be staying with a friend or relative in an urban apartment or condo?  

Returning from college?

Bedbugs are terrible creatures, you absolutely don't want them in your home, and if you have them you shouldn't spread them to others.

So how can you be certain not to bring bedbugs back to your own home after spending time away from home?

Fortunately heat is a pretty good way of killing bedbugs. I built this device with the following objectives in mind:
 - Safety - no pesticides; minimal fire risk
 - Ability to kill bedbugs by heating the luggage to an internal temperature of 125F 
 - Low-cost, easily available parts
 - Basic electrical skills 
(someone who knows how to install a new light fixture or outlet in their home safely).
 - Only using basic tools (drill, knife, screwdriver)
 - No soldering, no programming an arduino, etc.
 - Usable as a prophylaxis
(you should be able to use it every time you travel, whether you have encountered bedbugs or not)



Read on!





 
 
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Step 1: Why I built this device

Feel free to skip forward to the next step where we will start the build...

I recently had the misfortune to stay in a hotel - a good quality hotel that I had stayed in multiple times before - and had my first bedbug encounter.

I knew a bit about bedbugs because my Mom's apartment had bedbugs several years ago (they had crawled in from a neighbor's apartment). It took her almost a year to get rid of them - several whole-apartment pesticide sprays, repeated laundering of all her clothes and bedding, replacing the bed, etc. I did not want to have them in my home!

When I travel, I normally check my hotel room pretty thoroughly when I arrive (see http://bedbugger.com/2006/10/19/faq-how-can-i-avoid-bedbugs-while-traveling/ for tips) but this time I missed their little hiding place and woke up in the morning with bloodstains on the sheets (yuk! and it was my own blood!).

So now I had my luggage that's been in a hotel room with bedbugs for several says and I needed to be certain that I wouldn't be carrying them back to my home.

I bought some large trash bags on the way to the airport. When I got home, I unpacked in an empty bathtub (so I could see if any bedbugs had escaped), all my washable items went straight into a hot wash and dry, I stripped off and washed all the clothing I was wearing, and then I sealed my suitcase in two knotted trashbags and had a shower.

Bedbugs can live without feeding for up to 18 months. So now I had a suitcase with various non-launderable items including my favorite leather jacket inside that I won't be able to use for 18 months until the bedbugs inside starve to death.

What to do now?

I found a device called a "Packtite" for sale on the 'net: http://www.usbedbugs.com/PackTite-Portable-Heating-Unit_p_6.html which looks like it would do a reasonable job - but it's over $300, and I didn't want to spend that kind of cash on this problem.

Various sources around the 'net state that you can kill bedbugs and their eggs with a temperature of 125 degrees Fahrenheit.

This instructable is my attempt to produce a heater for luggage that could be built simply and easily to raise the internal temperature to 125 without destroying the luggage itself. Read on for the rest! 

Step 2: Materials

Picture of Materials

Everything except 3 items came from my local big-box hardware store.

For the heat chamber I used a 32-gallon galvanized trash can. It's not the prettiest thing, but I wanted to have a vessel that would be capable of containing the bedbugs in case they tried to escale during treatment, and I wanted something that would contain a fire in case the worst happened...

Heat is provided by ordinary light bulbs, kind-of like a giant easy-bake oven. Seven 40-watt bulbs would be the best, but you may want to have a few 60W and 100W bulbs on hand in case you can't get all the heat you need out of 40's. The beauty here is that you can regulate the heat output of the unit by changing lightbulbs of different wattages, thus removing the need for any fancy thermostatic unit.

The bulbs are held in place with standard hardware for light fixtures: porcelain sockets attached to steel outlet boxes. You'll need 7 of each. While you're in the store, make sure the sockets fit on to the boxes. I used non-switched light fixtures, but you could make your life a little easier later if you shelled out the extra dollar or so for switched light fixtures.

I wired this up internally using about 6 feet of 14/2 gauge NM solid copper household wiring with ground. That's going to be the quickest way but you could use stranded wire from an old 3-conductor extension cord instead if you prefer. 

The external cord was an old 3 conductor extension cord that I had and repurposed for this project. DO NOT, under any circumstances, use a 2-conductor cord.

A round replacement cooking grate for an 18" barbecue, and a remote cooking thermometer. Those items were way cheaper ($2 and $10 respectively) from the sports store than from the home store. I also bought a second thermometer with a long probe to monitor the temperature inside the can but outside the suitcase.

You will also need:
 - 15 3/8 inch clamp connectors for 1/2inch knockouts on ceiling boxes.
 - about 25 wire nuts (or the push connectors you'll see on the next page)
 - Electrical tape (get the high temperature kind)
 - 7 3/4" #10 bolts and 14 nuts to go with them
 - 7 ground screws (amazingly, the electrical boxes didn't come with them)
 - 7 4" sections of ground (bare), black and white insulated wire taken from the NM cable mentioned above to make pigtails for connections to the lapholders
 - a GFCI outlet on your home, or a GFCI socket adaptor. This is important for secondary safety.

Tools:
 - Hammer and old screwdriver for knocking out knockouts on the electrical boxes
 - Drill with assorted bits, including some means of drilling a 3/4" hole in metal
 - Wire strippers
 - NM cable ripper (not absolutely necessary, but will save a lot of time)
 - Screwdriver
 - Utility knife
 - Pliers
 - A voltmeter (Ohmmeter) or conductivity checker is a good idea.


 

Step 3: Prepare the internal wires

Picture of Prepare the internal wires
Cut the NM cable into 6 9-inch sections and strip the ends like so

Step 4: Start with the end-of-run box

Picture of Start with the end-of-run box

This box will be at the end of the run.

Knock one of the knockouts out of the side of the box, and install a cable clamp into the knockout. The cable clamp is important since it will prevent the cable from rubbing against the edge of the box and short-circuiting.

Connect the ground to the outlet box using a ground screw. This step is important for your safety! You must ground EACH box!

Run a #10 bolt (machine screw) out the bottom of the box and hold in place eith a nut on the backside of the box (not shown). Tighten well.

Connect the wires to the lampholder, following the manufacturer's instructions. The black wire is supposed to go to one terminal and the white wire to another; it is important not to reverse these. 

Tighten down the cable clamp screws.

Close the box and tighten down the screws holding the lampholder in place. Don't over-tighten, or you will end up cracking the porcelain.

Check your connections with a multimeter.
 

Step 5: Wire up the middle-of-run boxes

Picture of Wire up the middle-of-run boxes
P1050567.JPG
I chose a total of seven boxes and 7 lightbulbs because I didn't know how much power I would need, and figured that seven 100 watt bulbs would be more than enough. In the end I found that 370 watts was too much... but regardless I'm going to write this with 5 boxes and you could always build your own with as few as 2 boxes in the middle of the run. 

For each middle-of-run box, you are going to need to create a "pigtail" to connect the lampholder, and you are also going to need to connect to the next box in the run.  

Knock out two of the knockouts from opposite sides of the box, and install a cable clamp into each one. The cable clamp is important since it will prevent the cable from rubbing against the edge of the box and short-circuiting.

I used these fancy connectors shown here but wire nuts would work just as well. Start with the ground, you want this at the bottom of the box. Connect the incoming ground to the outgoing ground, and add a pigtail for the box. Connect the pigtail ground to the outlet box using a ground screw. This step is important for your safety! You must ground EACH box!

Connect the black wire from the incoming cable to the black of the outgoing cable, and add about a 4" pigtail to go to the lampholder. Repeat for the white wires.

Run a #10 bolt (machine screw) out the bottom of the box and hold in place with a nut on the backside of the box (not shown). Tighten well.

Connect the pigtails to the lampholder, following the manufacturer's instructions. The black wire is supposed to go to one terminal and the white wire to another; it is important not to reverse these.

Tighten down the cable clamp screws.

Close the box and tighten down the screws holding the lampholder in place. Don't over-tighten, or you will end up cracking the porcelain.

Check your connections with a multimeter.

Repeat for however many boxes you have.

Step 6: Wire the start-of-run box

Picture of Wire the start-of-run box
P1050569.JPG
For the start-of-run box, you are going to need join the flex cable for the plug to the next piece of NM cable going to the next box, and  to create a "pigtail" to connect the lampholder.

In my case the flex cable (extension cord) that I used for the project didn't have a plug on it, so I was able to do step 6 before step 7. If your extension cord has a plug on it already and you don't want to remove it, do step 7 first.

Knock out two of the knockouts from opposite sides of the box, and install a cable clamp into each one. The cable clamp is important since it will prevent the cable from rubbing against the edge of the box and short-circuiting.

I was having trouble connecting two solid wires and stranded cable to the same wire nut, and the push-in connectors don't accept stranded cable well. I used wire nuts to make pigtails to the push-in connectors, then used the push-in connectors for the rest of the connections on the box as in previous steps.

Start with the ground, you want this at the bottom of the box. Use a wire nut to join the flex cable ground (GREEN) to a short piece of bare copper from some NM to create a pigtail. Connect the incoming ground pigtail to the outgoing ground, and add a second pigtail for the box. Connect the pigtail ground to the outlet box using a ground screw. This step is important for your safety! You must ground EACH box!

Use a wire nut to join the flex cable hot (black) to a short piece of black cable to create a pigtail. Connect the black pigtail from the incoming cable to the black of the outgoing cable, and add about a 4" pigtail to go to the lampholder. Repeat for the white wires.

Run a #10 bolt (machine screw) out the bottom of the box and hold in place with a nut on the backside of the box. Tighten well.

Connect the pigtails to the lampholder, following the manufacturer's instructions. The black wire is supposed to go to one terminal and the white wire to another; it is important not to reverse these.

Tighten down the cable clamp screws.

Close the box and tighten down the screws holding the lampholder in place. Don't over-tighten, or you will end up cracking the porcelain.

Check your connections with a multimeter.

Step 7: Create an entry hole for the cable

Picture of Create an entry hole for the cable
Using a 3/4" drill bit (I used a step bit as shown), drill a 3/4" hole into the trash can, near the bottom.

Install a cable clamp, feed the flex cable through the cable clamp, and clamp down.

I haven't shown it here but I also drilled a small hole for the second temperature probe just above the cable entry point.  

Step 8: Install the light fixtures into the trash can

Picture of Install the light fixtures into the trash can
Place the light fixtures into the bottom of the can as shown.

Drill a hole into the can where each #10 bolt protrudes from the bottom of each electrical box, and secure from the outside with another nut. These are important for two reasons:
 - Mechanical rigidity, since the light fixtures are going to be holding up your luggage, and
 - Ground connection to the can. This might not be the very best way to ground the can, but I figure it would work. Perhaps other 'ible authors migth offer ideas here.

Step 9: Install Bulbs

Picture of Install Bulbs

Install lightbulbs.

I would start out with a low wattage like 40W for each bulb and work upwards from there if it's not hot enough.

Let me say I "should have" started like that... I actually started with 100W bulbs and had to work my way down...

Step 10: Place grate on top of bulb assembly

Picture of Place grate on top of bulb assembly
Place the barbecue grate on top of the bulb assembly. I found that it sat there on its own fairly well, but if you wanted to you could rig up some better kind of support mechanism. 

Step 11: Ready to test-fire

Picture of Ready to test-fire
P1050579.JPG

Take your luggage out and open it (best to do this outdoors). Place the probe from the remote thermometer in the MIDDLE of your luggage. Your luggage needs to hit 125 degrees in the middle to kill all the bedbugs, if there are cool spots in your luggage the bedbugs could make their way to a cool spot and survive the process, and you don't want that.

Remove anything flammable from your luggage. Remove any aerosol cans from your luggage. Remove anything at all dangerous from your luggage. Re-close your luggage.

Place the sensor from the remote thermometer outside the can, and put on the lid.

Plug into a GFCI-protected outlet. Outside, on concrete, away from any risk of fire.

You have two temperatures to monitor: using the long-probe thermometer in the hole above the cable entry, measure the temperature in the light assembly. I think somewhere in the range between 150-175F would be good here. Keep an eye on it for several minutes.

If the temperature is too high, you'll need to reduce wattage on some of the bulbs and start over. If it's too low, you'll need to increase the wattage. I'd do this about 40W or 60W at a time.

In my case 370W total produced a temperature of 175F in the bulb array for the first hour or so on a slightly windy day where the ambient temperature was 70F. Then the wind died down and the temperature went up to 200F, which was too hot because it partially melted some of the plastic on my suitcase. I'd recommend starting at 280W (seven 40W bulbs) and working your way up from there.

Step 12: Kill those bugs!

Picture of Kill those bugs!
P1050581.JPG
Keep an eye on the temperature gauges, especially the temperature under your bag because you don't want to melt anything down there. If it goes over 175, unplug, reduce the wattage, and start over.

When the internal temperature in the center of your bag (as measured by the remote thermometer) is 125 degrees, the bedbugs and their eggs are all dead and you are done. Unplug the unit.

I would leave my bag in there to cool, also because it will heat-soak for a bit and possibly heat any cold spots that weren't measured by the internal thermometer. This is also a safety precaution, just in case there happens to be a fire smouldering inside the can  (have you seen the movie, "Backdraft"?)

Step 13: Safety and future improvements

So I imagine a lot of folks will critique this over safety, and I agree with you :-)

I have 120 V in a big metal trash can. Then there are light bulbs inside just an inch or so away from the bottom of the can. That's a big electrical hazard. Ground it carefully, use a GFCI outlet, don't operate if any of the bulbs are broken, and your kids cannot be allowed to operate it, OK?

I wasn't really happy with how I grounded the trashcan itself (through the electrcial boxes). You could probably put a couple of extra ground screws into the trashcan itself and run some ground pigtails to them.

I was a bit worried about fire hazard with this. I am hoping that in the worst case if a fire did start, that it would be contained in the can and it wouldn't get much oxygen. Nevertheless, don't open the can after heating until the unit has cooled.

Air circulation wasn't that great in the can. You could add a fan inside, if you can find room for it.

A thermostat would be a nice addition, but it adds complexity.

I have a big metal trashcan to store. I think I will probably store the suitcase in the trashcan when not in use. You could find a more attractive solution by using a metal cabinet instead of the trashcan, I thought about using a metal garage storage cabinet and hanging it on the wall when not in use.

Please feel free to post improved low-cost lightbulb-heated metal cabinet bedbug killers on Instructables.com. Please credit me if you feel I'm credit-worthy. The more people out there stopping the spread of bedbugs the better!
Cdn Sapper3 years ago
Very good instructable, bedbugs really "suck" pun intended...one thing you might want to do is add switches to control each or groups of lights so you could run it with all to bring up the heat and then reduce the number of bulbs to maintain the temperature. A thermostat could also be added to regulate the temp.
arty4 years ago
Recycle a temperature limit-switch out of a gas furnace or electric water-heater. Water-heaters have two, and the lower switch is adjustable. It's range is from about 120 < 180, which sounds perfect for this task. If I recall correctly, the lower-limit switch on a gas furnace toggles at about 125 dF... but I don't remember whether it is opening or closing at that temp.

Very good idea. Thank you.
marcgr (author) 4 years ago
Check out my latest, improved version of this at:
http://www.instructables.com/id/Kill-bedbugs-with-your-Christmas-lights/
marcgr (author) 4 years ago
There's a great discussion going on over at http://bedbugger.com/forum/topic/build-your-own-luggage-heater

I copied a few of my comments back here:

- I agree absolutely, if you have no technical skills or if you are concerned in any way about safety, you should buy a UL-listed product like the Packtite instead of making your own.

- I agree absolutely, if you don't know what a GFCI outlet is or how to use one, you should buy a UL-listed product like the Packtite instead of making your own.

- I agree absolutely, the Hacktite should only be operated in a location where there is absolutely no risk of damage to property other than the contents of the hacktite, should the unit catch fire.

- Many of us live with "metal boxes that use electricity" today; ask anyone who owns a stainless steel fridge. Remember that 60 years ago just about any appliance that used electricity would have been made of metal and not plastic; devices today are safer than those devices of 60 years ago but the devices of 60 years ago were not intrinsically unsafe.

- Availability of incandescent bulbs: I don't think they are totally phased out until 2014, and in any case, you could probably still find them after that for many years at garage sales etc. If you buy your lightbulbs today, take one trip a week and have the "hacktite" on for a few hours after each trip, I'm sure they'd all last beyond 2020.

- I'm generally thinking the Hacktite would be operated outside and therefore if some BB's escaped through the lid or cord hole during treatment then it wouldn't be a big problem. If you are concerned, you could put some double-sided tape around the top and seal the cord hole.

- A dimmer would make it a bit easier to use. During my tests, I didn't find it a big inconvenience to open the unit and change bulbs to reduce the heat output (I started out with seven 100W bulbs in mine which was way too much; I ended up with a mix of 25's, 40's 60's and 100's totalling 370W at the end).

- I thought about a single heat source such as a hot plate or similar but couldn't find a commercial item with a low enough heat output; most hotplates, irons, heaters, hairdryers, etc are more like 1000W or 1500W. I also wanted to use something with a large surface area (multiple lightbulbs) so that the surfaces would be cooler and less likely to ignite a strap or something falling onto them.

- I don't know about cool spots. I assume the same issue arises with Packtite?

- I was really only kidding about DDT

- Good point about holding the temp at 120 for an hour. I saw some data that said that 125 kills everything in less than a minute, but follow whatever research you want to believe.

- I have no knowledge of the patents on the Packtite, but I don't believe there is a court in the world that would prosecute an individual for building one item for their own use even if that item infringed upon a patent of another. Where one might get into trouble is if one tried to set up a business selling hacktites if the hacktites infringed upon the patents in Packtite.

- Right now the Packtite is sold over the internet at $299 and I'm guessing the volumes sold are in the hundreds or thousands and the Packtite inventor/manufacturer is making a few bucks off of each one, as he rightly should. What I'd love to see is a large manufacturer put ten million of them on the shelves of retail stores next year (and every year) at $50 or less and the Packtite inventor make a dime or a quarter on each one through license fees to the manufacturer.

- I'm hoping this very discussion will encourage more people to heat their luggage, thus slowing the spread of bedbugs. Some people will build their own heater, some will look at the instructable, decide the effort/risk is too high, and decide to buy a Packtite instead.

carlos66ba4 years ago
Good idea! For those out there, I'd recommend not only grounding the unit, but also using an isolation transformer. In fact, that way, I'd use a 12 V line and bulbs inside so as to minimize any chance electrocution (won't happen with 12 V).
marcgr (author)  carlos66ba4 years ago
Thanks!

One major objective for me was to do this very low tech to make it as widely applicable as possible. This first version of this project could have been built by Thomas Edison.

An isolation transformer would improve the safety, but would add to the cost. you would need about a 400W transformer and that's not exactly a small item. Besides, Edison didn't believe in transformers :-)

Another thing I had thought about was wiring ten 12v bulbs in series, at least the current would be limited if you shorted out one of them. But then it would make it harder to control the power as I had orignally intended.



I understand your points. As for controlling the power: a simple dimmer would do. Alternatively, you can simply wire a diode in series with the lamps and this would halve the power (not much fine control!).
Hoopajoo4 years ago
Well, it is a good start to an idea that modern society definitely needs.
Have you considered removing the clothes from the luggage and utilizing a tiered racking system for even heat distribution and a PC fan for air flow? I think the PC fan should be sufficient as it is a closed system and therefore only minimal flow would be needed.
marcgr (author)  Hoopajoo4 years ago
There is good evidence that washing items on the hot cycle will kill bed bugs.

However, one of the ways that the bugs like to travel is in the seams of your luggage, and there was no way to launder my whole suitcase...

Good idea on the fan, when I return from my next trip I will see if I can fit one in somewhere!