How to monitor open refridgerator doors?

[RichTJ99]

Hi,

After my wife accidently leaving the freezer portion of the downstairs fridge open overnight, I now have a great excuse to monitor the two refridgerators in the house. I was thinking I could use a DS10A as I have a bunch sitting around. I dont really like the idea of having two DS10A's sitting on top of the fridges (total of four) but if thats how it has to be, thats how it has to be.

Is there a better way? I have a RFXtemp gauge in my attic (with an 800 for the wireless).

I was figuing that after 5 minutes the alarms would start going off.

Any suggestions would be welcome!

Thanks,
Rich

 

[politics123]

Hi,

After my wife accidently leaving the freezer portion of the downstairs fridge open overnight, I now have a great excuse to monitor the two refridgerators in the house. I was thinking I could use a DS10A as I have a bunch sitting around. I dont really like the idea of having two DS10A's sitting on top of the fridges (total of four) but if thats how it has to be, thats how it has to be.

Is there a better way? I have a RFXtemp gauge in my attic (with an 800 for the wireless).

I was figuing that after 5 minutes the alarms would start going off.

Any suggestions would be welcome!

Thanks,
Rich

I don't use X10, but don't the DS10A have external contact-closure detection? If so, why not wire in a couple of plunger contacts in parallel, one for the fridge and one for the freezer. Then you only need one DS10A per fridge. You wouldn't be able to tell which door was open, but I think you'd be able to figure that out upon further inspection

 

[TonyNo]

If you can still find the new-style Radio Shack version of the DS10A, they have two channels. The problem with this is that RS discontinued them, so you may not be able to find them.

 

[beelzerob]

This is a really pertinent topic for me, too. Our french-doors refrigerator does not EASILY close (it's got a funky mechanical mechanism to seal up where the 2 doors meet) and I've already several times found it still ajar. I was also wondering how to wire that. I think I could almost get away with magnetic reed switches on the top. I'd rather not do anything that involves drilling into the refrigerator...

 

[AnotherOne]

Here's what I've done after some one left the drawer slightly open all night causing all the ice cream to melt.

I bought one of the radio shack wireless indoor / outdoor temp sensors. I have set the display to beep if it goes above 15 degrees. Not a great situation (I'd like it to go into my Elk M1, so I can have rules), but so far it's worked okay.

So, how about a wireless temp sensor for the elk m1?

 

[BraveSirRobbin]

For temp monitoring you could also use a mechanical sensor and monitor the contact closure high and low set points.

 

[RichTJ99]

For temp monitoring you could also use a mechanical sensor and monitor the contact closure high and low set points.

BSR, can you hook that up to a DS10A? If so, how does that work?

 

[BraveSirRobbin]

For temp monitoring you could also use a mechanical sensor and monitor the contact closure high and low set points.

BSR, can you hook that up to a DS10A? If so, how does that work?

The unit is basically a mechanical thermostat. A metal rod is connected to a thermally sensitive spring mechanism and moves along a grid to read temperature. There are two metal rods on either side that you "set" to desired monitoring temps. The left rod moves to the lower monitoring temp and the right rod moves to the high monitoring temp. All three metal rods are connected to terminals (so you can connect wires to them). When the temp rod moves "against" one of either the lower or upper rod it will make contact between it and that rod's terminal.

Thus you can use one DSA10 to monitor both upper and lower temp limits, or two and have them monitor the upper and lower contacts separately.

I have the larger version of this in my wiring closet connected to my Ocelot's SECU16 inputs so I know when the temp gets to high or low.

I think EBay will have these units every now and then. Do a search on "Winland".

Edit: Found the larger version for $26 shipped, but this is a pretty big unit.

 

[politics123]

Okay, I have a few more "crazy" ideas:

1) Fun with current transformers. Your fridge will operate in one of two ways: ( a ) it'll shut off the motor whenever the door is open or ( b ) it won't. Note that a fridge motor will run every 10-15 minutes to keep the temperature constant. Wire in a current transformer and an automation rule. If your fridge is of type (a), detect the lack of the motor running for > 20 minutes. If of type ( b ) detect the motor running for longer than normal (say.... 10 minutes).

Alternatively, the fridge probably draws very little power when the motor is off and the lightbulb is off... just detect power draw for more than 15 minutes in a row.

2) If you only care about the fridge side (especially those people with french door side by sides), how about wiring a contact into the fridge light. (This would be easier if the fridge used a normal lightbulb). Wire a relay in sequence with the bulb. Now that I think about it... could one of those X10 screw-in adapters work? In the ZWave world, I could screw-in one of those bulky intermatic Zwave adapters, and then check every so often for the status of the adapter. When the door is closed (light is off), the zwave adapter wouldn't exist on the network. When the door is open (light is on), there would be power and I'd be able to see the adapter and get its power output level. LOL... I can just imagine my WAF plummet if she saw that bulky adapter sitting in the fridge

3) Use an Infrared beam generator/detector and reflector. Put the reflector on the door, and alarm if the IR beam is broken for more than 2-3 minutes. Generator can go either behind the fridge, or on the ceiling. Might be a PITA to align, and depending on beam width, you might not be able to detect a small opening in the door.

4) if you already have a door-open buzzer, just attach a relay to it

5) LOL --> my personal favorite and the most a rube goldberg of all of my suggestions --> put a wireless microphone next to the door-is-open buzzer. Broadcast the sound over your whole-house notification system/intercom/stereo, etc. This will do 2 things: ( a ) you'll hear throughout the house everytime someone has a case of midnight munchies ( b ) if you adjust the volume correctly, the door-is-open buzzer will scare the living sh-t out of you in the middle of the night

Okay, I need to get some sleep now.

 

[beelzerob]

Haha...I love 'em!

1) Fun with current transformers.

I have some transducers that work with my datanab I/O module, and I'm already using them to monitor pump operation. It wouldn't be hard at all to wire up a plug and monitor the entire fridge. I guess I'd have to monitor it for some time to see what its normal characteristics is before defining the boundaries...but it seems like it might still be error prone. You're basically using a sensor (transducer) to measure a reaction (current draw) to the actual problem (door open). I'd still rather have some way to just check the door isn't fully seated.

In fact, for our fridge, it's really only 1 door that's a problem (of the 2 french doors). One door has no obstruction to closing, so it closes quite easily. The other one has the funky contraption to create the door seal, and that's the problem door.

2) If you only care about the fridge side (especially those people with french door side by sides), how about wiring a contact into the fridge light.

Not a bad suggestion. I'd have to check and see if the light actually stays on for the entire time the door is ajar...it might cut out just before the door makes the final movement to close. Also, how would you get the wires out without affecting the door seal, or is 24 ga too little to worry about. I know for myself, unless I could make it absolutely disappear, there's no way my wife would let me have wires running from the light socket to the door and out...

As for alerting the whole house, I would expect at some point, should I arrive upon a method here, to include it in the normal set of house notices...so probably not a siren and lights going on and off....but some kind of notification tone occasionally. Something like that.

Great ideas, pol.

 

[123]

Lots of interesting ideas. Let me know if the suggestions that involve sticking an RF tranceiver inside a grounded steel box (a.k.a Faraday Cage) actually work.

On second thought, maybe they do if the door is ajar!

 

[HoustonFirefox]

How about wiring a magnetic switch to the door. Magnet on the door and the switch on the side/top/bottom on the freezer itself?

This (IMHO) is the quickest way to go then you could have your Elk announce that the freezer is open and send you a SMS message on your cell phone (via email).

I only suggest this because you can carefully control the proximity of the magnet on the door and it's switch to give you any level of "sensitivity".

Good luck with your project!

 

[felixrosbergen]

This is a really pertinent topic for me, too. Our french-doors refrigerator does not EASILY close (it's got a funky mechanical mechanism to seal up where the 2 doors meet) and I've already several times found it still ajar. I was also wondering how to wire that. I think I could almost get away with magnetic reed switches on the top. I'd rather not do anything that involves drilling into the refrigerator...

HI beelzerob, is this a serious problem with the french door fridges....i am looking to get one of them (GE Profile series). Please let me know if the issue is serious enough to recommend against them. I looked at the mechanism in the shop and thought it would be ok. Good idea to monitor it though.

 

[beelzerob]

HI beelzerob, is this a serious problem with the french door fridges....i am looking to get one of them (GE Profile series). Please let me know if the issue is serious enough to recommend against them. I looked at the mechanism in the shop and thought it would be ok. Good idea to monitor it though.

Hehe...well, don't be confused, I had no say in the purchasing experience. And in every way that she cares, she LOVES it.

But purely from my user experience....I'm very used to a refrigerator door that, if you give it just a slight push, you can be assured it will end up closed (assuming there's no mayo jar in the way). That's not true with these doors. The right door will close just like that....too easily in fact. It doesn't have any mechanism, so it closes reeeeally easy. The left door takes some serious momentum to make sure it makes it through the transition.

The result is that if I'm too soft with the left door, it won't close all the way...and if I'm too hard with the right door, I can hear all of the stuff banging around as it slams shut.

All I'd suggest is that you spend some good time with it in the showroom, and just close the doors like you would a normal refrigerator....with an elbow because your arms are full of meat, cheese, tomato, lettuce, and butter.