Temperature Data Logging, fridge, freezer, coach, etc..

[marcsbigfoot20b]

Always wanted to see what my dometic fridge was doing.
Got two Sensor Push units to test. They are small 1.5” x 1.5” x .7” squares.
I think they can hold 2 weeks of data before they overwrite , so I just connect to my iPhone or iPad and it auto uploads by Bluetooth or WiFi and adds the data, BT range is impressive.
They do both temp and humidity.
A few pics of testing. Looks like at ambient of 83 outside and 79 in the fridge, it took exactly 3 hours to get to 40 on propane with Amish cooling unit and internal and external fans.
The long test was Mexico trip.

[wopachop]

I pulled the trigger too. Went with the RV whisper unit and several temp readers.

Im curious the difference between my food cabinet storage and the trailer interior. Might try insulating a cabinet with foam board and see if that improves anything.

[Jframpey]

Well, after reading this thread I plunked down $99 and bought two of the SensorPush devices. They are now reporting the temps in my brand new 12 volt compressor fridge and freezer.

DW lost all faith in our Dometic fridge/freezer. It has never worked reliably on propane and has limited cooling capacity on 120V... Our trailer is a rear kitchen - I think the suction at the rear while driving keeps blowing the propane flame out. My DW is already paranoid about food spoilage. First time we opened the fridge and found “not cold” food after a day of travel, she lost confidence in the old fridge - i’ve been looking and finally dropped $1400 on a Unique 24V/12V off grid compressor fridge.

The addition of these sensors should provide proof that the new fridge is maintaining cold temps. Maybe we can travel with less complaining. 😮

[wopachop]

Dang both those devices look awesome. Is anyone aware of other RV monitoring systems?

Was thinking of getting two of the little blue $50 sensors. But then the RV whisper looks really interesting as well. How does it work if you have Wifi at your RV then you can view stats with your cell phone while away?

edit: Nevermind i see it needs wifi. Has anyone tested how many watts it uses? Video i watched said you need to use the included cord because other cords might not have enough power. That makes me think its up at 2amps at 5v?

[marcsbigfoot20b]

eb145 wrote:
As long as we're talking about data logging in RVs...

I use a wireless monitor system that logs data every 5 minutes with multiple wireless temperature sensors (fridge, freezer, Indoor, Outdoor, Wet bay) and also battery volts, amps, watts and state of charge. I can see my RV temperatures and battery data over the internet and get email alerts if I want.

RV Whisper monitor system

pricing

They are working on adding wireless propane sensors. shore power monitoring and door open/close sensors.

All kinds of cool stuff I don't need, but can't resist. Actually, I really like knowing my dog is not overheating when I have to leaver her behind for a few hours. And when I camp without electricity for a week it is nice to be able to see how my solar system recharged my batteries (or not) every day.

Yeah, i cant resist either...
Sensor push dataloggers,
Mopeka tank check wireless propane tank sensors
Battery tender WiFi battery monitor
LevelMatePRO wireless level
Tire minder wireless tire pressure monitor
Wireless backup camera

That’s just the wireless stuff, lol. I guess I’m just a super geek.

[eb145]

As long as we're talking about data logging in RVs...

I use a wireless monitor system that logs data every 5 minutes with multiple wireless temperature sensors (fridge, freezer, Indoor, Outdoor, Wet bay) and also battery volts, amps, watts and state of charge. I can see my RV temperatures and battery data over the internet and get email alerts if I want.

RV Whisper monitor system

pricing

They are working on adding wireless propane sensors. shore power monitoring and door open/close sensors.

All kinds of cool stuff I don't need, but can't resist. Actually, I really like knowing my dog is not overheating when I have to leaver her behind for a few hours. And when I camp without electricity for a week it is nice to be able to see how my solar system recharged my batteries (or not) every day.

[dougrainer]

NRALIFR wrote:
You don’t think there’s anything to learn from 4-5 days of real-time operational data? If you were monitoring your fridge with a unit like this and became familiar with what “normal” looks like, you could spot a problem before it became an emergency.

Cool down time, cycle frequency, cycle length, high and low temps, and the ability to compare this data to ambient temps is all something a glass of water can’t do. I seriously doubt a sick cooling unit could produce those same plots.

If you were logging data from a temperature probe in a glass of water in the fridge, you would see the initial cool down time take longer, but then you would see very little change in the temperature of the water once the cooling unit started cycling. You wouldn’t be able to see the high and low points nearly as well, and the water temperature would always lag behind what the cooling unit was doing. A glass of water also isn’t going to tell you about an intermittent problem that occurred several hours before you took its temperature.

:):)

MY Temp logger is NOT in a glass of water. It takes the complete interior lower box temp every 15 minutes. It lays on one of the shelfs. I mentioned the glass of water for those that want to see the CORRECT way to determine the inside temp of an RV refer. NOT for intermittent problems. Doug

[NRALIFR]

You don’t think there’s anything to learn from 4-5 days of real-time operational data? If you were monitoring your fridge with a unit like this and became familiar with what “normal” looks like, you could spot a problem before it became an emergency.

Cool down time, cycle frequency, cycle length, high and low temps, and the ability to compare this data to ambient temps is all something a glass of water can’t do. I seriously doubt a sick cooling unit could produce those same plots.

If you were logging data from a temperature probe in a glass of water in the fridge, you would see the initial cool down time take longer, but then you would see very little change in the temperature of the water once the cooling unit started cycling. You wouldn’t be able to see the high and low points nearly as well, and the water temperature would always lag behind what the cooling unit was doing. A glass of water also isn’t going to tell you about an intermittent problem that occurred several hours before you took its temperature.

:):)

[dougrainer]

JimK-NY wrote:
Maybe a more relevant test would be to put a couple of six packs of room temperature beer or soda into a refrigerator and see how long it takes to cool them.

Correct. You put a glass of water in the refer. You run the refer 24 hours on max cold. Then you take a temp reading of the water. This will give you the state of the condition of the refer and its cooling capacity. Doug

[JimK-NY]

Maybe a more relevant test would be to put a couple of six packs of room temperature beer or soda into a refrigerator and see how long it takes to cool them.

[2manytoyz]

It's the curmudgeon attitude that tends to drive people away from these forums! Hint: Nobody is asking for your approval or disapproval! If you have nothing to add, then don't. /rant

I've done the same testing on my fridge, and mine took an extra hour or so to stabilize. The common suggestion was to start the fridge the day before loading and travel. Now I know I can start it that morning (if necessary), and be good to go by lunchtime.

The sensors I'm using are made by Lascar. Smaller than yours, record for months if desired, but must be connected to a computer to download the data. Thanks for the links for yours. Those would be better for real-time data.

I purchased an Engel fridge/freezer for traveling. It has a dial thermostat, which is almost useless. Works on a temperature delta, rather than a physical number. So if I leave it in my parked vehicle, with it set 30 degrees below ambient, when the vehicle heats up in the sun, the temp in the fridge rises too.

I built an external digital controller, and 3D printed an enclosure for it. Now the temperature stays where I want it, and the hysteresis is adjustable.

The article is here: http://www.prepared-one.com/engel-thermostat.html



Keep nerding on! I'm with ya...

[dougrainer]

As a Professional RV Tech, I have 2 Temp Datalogger USB sticks I use. I use them for refer temps over time when a customer states that the refer temps go up and down and I use them when a customer states his roof AC's cannot keep a cold temp in the RV on very hot days. It shuts them up, when I produce up to 2 weeks of 24/7 monitoring taking a temp every 15 minutes. I log it and then print out the graph's and hand to customer. MOST effective tool for these type complaints. Doug

[marcsbigfoot20b]

Sorry guys I’m a tech junkie, I fix the machines that make microchips for a living so I like this kind of stuff.
I have accurite temp sensors but they only show highs and lows, no data logging to see what happened all the time.

I tested the cool down time on empty fridge, then filled it up with food, FYI.

I also use them in my house and outside, the Bluetooth range is really good.
Uses are limited to your imagination.

You can also set alarms for the temp to alert if let’s say the flame blows out on your fridge while traveling and the temps get over 40. I’m in Phoenix so when traveling in 115 temps it’s good to know what’s happening.

[NRALIFR]

I keep a close eye on my fridge temps while on the road too, tho I’m just using a a wireless unit. I like knowing it’s working as it should, and more importantly, when something is wrong. I can tell something isn’t right long before the meat, milk, beer and ice cream is in any danger.

Thanks for making me aware of these, I’ll have to check them out.

I try to avoid gastrointestinal “surprises” as much as possible. :E

:):)

[fj12ryder]

Ralph Cramden wrote:

fj12ryder wrote:

Ralph Cramden wrote:

vermilye wrote:

fj12ryder wrote:
Some information on the sensors you used, their cost, and where you got them would be nice. I kind of like the idea, but wouldn't want to spend a lot of money for them.

SensorPush

Amazon

I guess if dropping $50 to see the fridge temp on your phone is worth it to you, then it's worth it to you.

I have a much more cost effective method of knowing the fridge temperature. I pull out a beer and if its not cold I know somethings wrong.

You could always try the meatloaf after, unknown to you the fridge has been off, and see if you get sick. Both work.

But only if you eat meatloaf, try slathering it with some hot mayonnaise. $1.00 thermometers do a fairly decent job too. One thing is for sure at RVnet, things are complicated and get more complicated as time goes by.

Don't like it? Don't use it. Doesn't get much simpler than that. At the same time don't belittle people who do like gadgets. If it weren't for them you'd still be using a horse and wagon.