Accurate Freezer Thermometer?

[Quattro Pete]

Any recommendations for an accurate freezer thermometer? I already ordered this one, but I'm not sure of its accuracy. Typically in such thermometers, accuracy isn't very good at the extreme ends of the scale, but I'm having a hard time finding one that goes much below -20F. I have an IR thermometer, but I'm not sure how good these things are at measuring freezer temps. I am trying to monitor the temp of my chest freezer. The other day I put a quart of ice cream in there, and 24 hours later when I took it out, it was very soft - on the verge of turning to liquid.

 

[Barkleymut]

make sure and don't block the area where the cold air is blown into the freezer. During the early stages of coronageddon I have had to shuffle things around in our fridge since the milk that was right next to the fan/blower/cold air shooter thingy was getting frozen and stuff in the middle shelves was not cold enough.

 

[Donald]

Your chest freezer should get things like ice cream rock solid. Not sure there is a fan to blow the cold air around in a chest freezer. You can typically pack a chest freezer as full as you want without issue. I only get some frost around the area where the top seal is. If it gets really bad it might not let the top close 100% which would compound the problem.

 

[Donald]

You should be able to (with IR thermometer) pull off the top few items and aim at an item down a bit to get a reasonable temp. Its probably a few degrees colder than what the IT thermometer says.

 

[JohnG]

Why do you need -20F? Most foods are frozen at maybe 0 to -2F.

 

[Quattro Pete]

Originally Posted by Barkleymut

make sure and don't block the area where the cold air is blown into the freezer.

This particular one doesn't have such area. The interior is lined with solid aluminum (I think?).

 

[Quattro Pete]

Originally Posted by Donald

You should be able to (with IR thermometer) pull off the top few items and aim at an item down a bit to get a reasonable temp. Its probably a few degrees colder than what the IT thermometer says.

I'm seeing -12F with IR thermometer pointed at items toward the bottom of the freezer. That particular ice cream container was sitting closer to the top. It has since firmed up quite a bit, after I moved the temp dial from the middle more toward the "coldest" setting.

 

[Quattro Pete]

Originally Posted by JohnG

Why do you need -20F? Most foods are frozen at maybe 0 to -2F.

I don't need -20F. I just wanted the scale of the thermometer to go below -20F so that the readout of actual temperature wouldn't be so close to the end of the scale, for the reason I mentioned earlier.

 

[Donald]

Nothing happens very fast in a chest freezer. Take reading in morning after a night of it running and not being opened.

 

[Quattro Pete]

Originally Posted by Donald

Nothing happens very fast in a chest freezer. Take reading in morning after a night of it running and not being opened.

Yes, i adjusted the temp yesterday, and measured the temp today.

 

[mk378]

Check the door seal. It needs to seal all the way around. Usual advice is to close the lid on a dollar bill and make sure the bill is held in place. Repeat the test in several places. Chest freezers are cooled by coils embedded in the interior walls from the top to about 6 inches down. The cold air then naturally falls toward the bottom. +1 on nothing happens fast. If the ice cream wasn't well frozen when you put it in, and especially if it was near the top, it will take a long time to freeze.

 

[Quattro Pete]

Originally Posted by mk378

If the ice cream wasn't well frozen when you put it in, and especially if it was near the top, it will take a long time to freeze.

Actually, it felt fairly hard when brought in from the store and put in the freezer. Then 24 hours later, it was mush. I suspect wife may have not closed the lid properly, but we'll never know at this point. I just want to make sure the freezer isn't broken, and if it is, get it fixed while it's still under warranty.

 

[Quattro Pete]

Originally Posted by mk378

Check the door seal. It needs to seal all the way around. Usual advice is to close the lid on a dollar bill and make sure the bill is held in place. Repeat the test in several places.

Can you elaborate on what "held in place" exactly means? If I put a bill and close the lid, I can fairly easily pull it out without a whole lot of resistance, pretty much anywhere around the perimeter of the seal. There is one slight indentation on the seal - see pics below, which was there since the beginning - not sure if this is something to be concerned about? Should I demand it be replaced?

 

[Lou_Boyle]

Another factor in chest type freezers is the fullness factor. Packed freezers are slower to chill, since more (most) of the cooling in a full freezers is by conduction rather than air circulation, Also, anything at or above the level of the cooling coil just doesn't freeze as hard. My mother will not stop buying food until the lid won't close on the last pizza.she tries to put in there and everything on the top layer of her freezer is merely crunchy frozen. For a freezer thermometer I use one of the indoor/outdoor thermometers from the garden center at Lowes that has a wired outdoor sensor. Cheap, accurate, and the wire is flat so it can be taped down for minimal disruption of the gasket seal. There are so many factors involved in IR thermometer accuracy that you can think of them as in the ball park readings rather than a precise number.

 

[MasterSolenoid]

For my Frig (not freezer) I have two Digital Thermometers sitting side-by-side. For the Freezer, I have one Dial Type (same as what Quattro ordered). New Freezer - Read the Owners Manual and see what pointers you pick up. IR Thermometer - Read the Owners Manual and see what the accuracy and range is. Although it seems you may have already corrected the temp by turning the Control higher. Lou Boyle has a good suggestion with using an Indoor/Outdoor Thermometer with the Sensor inside and the Thermometer mounted on exterior. I guess that's the way it's done. It's got me thinking. What about a 'Wireless' Outdoor Thermometer. Sensor inside freezer / Readout on wall near Freezer. https://www.lowes.com/pd/AcuRite-Di...CO7uiuSRiekCFbEDiAkdMtMOQg&gclsrc=ds

 

[Quattro Pete]

Originally Posted by MasterSolenoid

What about a 'Wireless' Outdoor Thermometer.

Wireless certainly helps with convenience as you don't have to open the freezer every time you want to check the temperature. But is it any more accurate than the cheap analog one?

 

[Leo99]

Freezer is 0°F not -20°F. The graphics on that thermometer are a little whack.

 

[Quattro Pete]

Originally Posted by Leo99

Freezer is 0°F not -20°F. The graphics on that thermometer are a little whack.

Most places recommend freezer temp of 0F or below, so the graphic on that thermometer is just fine, IMO. My point was about diminishing accuracy of an analog gauge as you start moving away from the center of the scale. As was noted by others, a typical chest freezer will have higher temperature near the top and lower temperature near the bottom, so if you want 0F near the the top, you'll probably end up with somewhere around -10F near the bottom, which is fine. There is no harm in keeping the temp below 0F, other than higher electric bill, of course. https://solutions.rdtonline.com/blog/what-is-the-ideal-temperature-for-commercial-freezers

 

[Dave9]

Precision on a thermometer for this isn't really important. If it's off by, say 2 degrees, even 5 degrees, you're still going to get the needed info about whether it is staying at a suitably cold temperature. I would not turn the temp down more, instead make sure the door seals are in good shape and that everyone opening it, makes sure it closes good. Yes it uses more power, but also cycles the compressor more, wearing it faster. You should not have that big of an issue keeping the bottom at 0F, and having less than 10F difference at the top, unless your door seal is shot. A fully packed deep freeze with a good seal, will have no problem keeping food at the top, completely frozen. It is far better to keep it packed full of food (or frozen water blocks, or even empty containers holding stagnant air if nothing else) so that each time the door is opened, there is far less exterior hot air exchange. I highly prefer the ice blocks (or here, I grow tomatoes in summer and freeze blocks of those too) because they can keep food cold for several days during a power outage if you can resist opening the freezer much. It's also handy to have ice blocks, to just spontaneously grab and toss in a cooler for an outdoor event.

 

[MasterSolenoid]

Originally Posted by Quattro Pete

Originally Posted by MasterSolenoid

What about a 'Wireless' Outdoor Thermometer.

Wireless certainly helps with convenience as you don't have to open the freezer every time you want to check the temperature. But is it any more accurate than the cheap analog one?

Look at it this way; If I'm using a Wireless Thermometer and it's reading +10* F (for 12 Months) and at any time in the future it's reading +15* F and then +20* F I might start suspecting a problem is developing and head it off at the pass / doing so would save a Freezer full of food. So, knowing that the temperature is consistant is as important as to what the temp actually is Also, put your Dial Type Thermometer in the Freezer in case the batteries wear out on the Wireless.