I found a broken chest freezer dumped on the street and plan to turn it into a honey warming cabinet. I have a thermostat and a 200watt ceramic infrared heat lamp (intended for reptile terrariums). The plan is pretty basic- drill a hole into the freezer to get the lamp cable and thermostat probe in- mount the lamp at the top- and control it with the digital thermostat. The one thing I am wondering is: where should I put the thermostat probe inside the freezer? The lamp actually generates quite a lot of radiant heat, and I am slightly concerned the wattage may be too high. If I put the probe somewhere where the lamp beams can hit it- I imagine it will heat up and switch off fairly quickly. That might cause the lamp to cycle on and off more than I would like. Conversely I could put the lamp in a position where it is shielded from the beams- but then I’d worry the lamp would pump out too much heat before switching off.
My thermodynamics are not the best- does anyone have any ideas for me?
I was just thinking the same thing dawn, and the thermostat I have has a second plug on a timer that could power the fan- so that would be very easy to add as well. It’s the placement of the temperature probe that has me stumped at the moment? I might look at what reptile owners do as I assume they plan not to fry their pets.
Hiya Jack, most cabinets I’ve seen use an old 60-100w globe as a heat source. I think yours is overkill and cause over
temp issues and short cycling issues as you have stated. If you put the thermostat sensor in a jar of water you should get a more constant temp.
I like @skeggley’s suggestion, but I have a couple more thoughts for you. Heat transfers by 3 methods, as we all remember from physics lessons at school:
convection
conduction
radiation
Convection will be dealt with by the fan, rapidly dispersing heat around the “cabinet”.
Conduction should not be a problem.
Radiation is the only remaining issue. To overcome that, you need to shield the bulb in some way. I would be tempted to put the lamp inside a large old metal can, and have the fan blow the hot air out of that. No direct radiation then, and you could put your thermometer in a jar of water, as suggested.
Of course we our doing our classic trick of overthinking everything here! Where is @busso when you need him??
As the chest freezer is well insulated I like @skeggley’s idea with a simple incandescent light globe, beyond that I agree in thinking it you are going to over complicate it. You might want to try different wattage globes to warm the honey so it is consistent, too much heat and the honey on the outside of the pail will become warm much quicker than the honey in the center, so aim at slowly warming over a couple of days might be the way to go with it.
Cheers
that’s the problem with having the sensor in water I think. The lamp will stay on permanently until the water heats to 45C or whatever temp I have set. I am thinking long before that the exterior surfaces will be roasting. My though was if the probe is exposed to the air and the radiant heat to a degree- it will relatively quickly switch off. then the heat will sink into the mass of honey a little- and it will go back on. Over time I would have thought the temperature will equalise with everything at 45c?
I can get a 50 watt infrared globe and perhaps that’s a safer way to go. the 200 watt one is used for reptiles though so I would imagine it should be able to work safely reptiles being somewhat more sensitive to roasting than honey…
as for putting the lamp in a tin- that may work- but in a way I thought the radiant heat bouncing around inside the freezer would be a good thing- warming all the surfaces. the freezer has a reflective alloy finish on the inside distributing heat everywhere?
heat is a weird thing phenomena you start to think about it. And as for cold- in reality there is no such thing…
I don;t think I’m over-complicating it: basically all I have is a heat source and a thermostat to control it. (and a fan) seems pretty dang simple?
I have a pet electric blanket that uses 20 watts of power and candied honey is in a fluid state after 2 days on my kitchen bench, now that is simple. Slowly warming the honey. The honey in the bottom of the pail on the electric blanket will heat first transferring the heat upwards to the colder honey.
Do you really need to thermostatically control the heating? To my thinking it isn’t needed if you slowly heat the honey in the insulated chest freezer cabinet.
Cheers
45 seems high! Are you trying to uncandy the honey or stop it from candying?
I remember reading somewhere honey doesn’t candy if kept over 25 degrees and that over 40 degrees you get honey degradation. Seems to be that the sweet spot would be around 30-35?
45 will uncandy honey completely so perhaps that’s your intention?
yes- that’s what it will be for. Also for honey storage at lower temps. Also to warm honey prior to pressing so it will press easy. Different temps for each job. Today I just cut out two boxes of foundationless comb- it isn’t candied but very thick. I’ll warm these buckets to around 35c prior to pressing:
agreed and thermostat isn’t required- but the thing only cost $20- and it gives precise control. A warming mat does sound like a good option - assuming it can get the buckets up to 45c or so. I could easily sit that in the bottom of the freezer.
I have no idea what the honey in a pail gets up to in degrees C but in 48 hours it goes from crystallized honey to readily run from the pail gate into tubs. I bought the pet warmers on EBay for $22 incl delivery that use 20 watts.
Food for thought, a couple on the freezer chest floor with a hole made in the side at the bottom for the power cables and you would have an insulated honey heating cabinet which would work fine in my opinion for a minimum of power usage.
Cheers Jack
Jack, I think the best thing to do is make it, then use it while monitoring what’s happening so you can make appropriate adjustments along the way. Then report back with your findings.
Crickey, no pressure.
I’m thinking the 100 watt globe. Having spent 3 years in the tropics we had 60 watt globes in the bottom of the wardrobes. This was to create a warm draft to stop your clothes going mouldy.
A 100 w globe would bring a closed cabinet up to 35 deg I would think.
Use a chicken brooder thermostat. They operate around 35 deg C (95 F) and easy to rig.
I made a chicken brooder with an old toasted sandwich maker as a heat source inside a spindryer spinner (to protect the chickens) and a chicken brooder thermostat.
Thinking about the above, a more reliable source than a globe might be needed. Incandescent lamps do not like being switched on and off, as this would be maintaining temperature. Why I went for the old sandwich maker.
I would also look at an insulated standing cabinet as I don’t like chest freezer much because everything is on top of one another. I know they are much more efficient but not convenient. An old fridge or standing freezer or a insulated home made cabinet would give much more convenient access.
this chest freezer is longer than most- very big. It’s not one of those standard ones. Maybe twice the size. I would also prefer shelves, whatever- but this is what I have and it’s highly insulated. I will mostly use buckets so it’s all OK and actually good for that- I can stack them two high and could theoretically store a few hundred kilos. Don’t need a chicken thermostat as have a digital one that I can set so easily at any temp I like.
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