so I have a crock pot with a broken crock (or is it pot?) the shell with the heating element is fine as is the lid which fits nicely into the shell. So I filled it with river rocks (after washing them) and turned it up. once the rocks warm up it does a good job heating a smallish bedroom, you can remover or twist the lid sideways to get a large bump in heat out of it and on warm or low it keeps the room at a livable temperature.
my question is how does this compare to a regular old run of the mill space heater with the fan and the cycling off and on all the time. Energy wise that is? (one huge benefit, the crock pot is 99% silent, just a few creaks during warm up/cool down)
120ac 60 hrtz 270w I believe is the rating on the bottom.
Any resistive electric heater should be effectively close to 100% efficient, in terms of converting electrical power into heat.
That is, heat is normally an unwanted by-product of converting energy from one form to another, so if the goal is actually to convert to heat energy, it’s easy.
One way it might not be energy-efficient as a space heater is if, on occasion, it provides too much heat and you don’t have an automated control to cycle it off (for example, if you control the upper limit if the room temperature by opening a window)
The heating elements will be equally efficient, but the space heater fan may distribute the heat better through the room, and the cycling will turn it off when the room is warm enough, so that will be slightly more efficient.
The space heater will have safety switches to turn if off if it overturns, which the rock pot won’t. But crock pots are bottom heavy. so overturning is unlikely.
The biggest economy savings is coming from the fact that this is a broken crock pot that would otherwise be discarded. But you have adapted it as a space heater, thus saving the cost of buying one.
thought about the fan, I have a small desk type fan I could put some place high up pointed down at the pot to get good distribution, I hadn’t considered the auto shut off aspect, but it is a large (7 quart) pot full of rocks, it will not fall over easily at all.
Is it important that the crock is broken, I mean would it work just as well with an unbroken crock filled with river rocks? I like the idea, and I also wonder if it would be OK to put some water in the crock for moist heat, or is that crazy?
It shouldn’t be as bad as running something like a hot water heater dry, but I would expect that running a crock pot near-constantly without some sort of liquid conducting the heat away will result in the heating elements running hotter than they’re supposed to, possibly resulting in a shorter heating element life. But, hey, if you’re otherwise going to throw it away who cares?
Let us know how it works. If we don’t hear back, we’ll assume it burnt your house down.
Doesn’t a crock pot have a thermostat to prevent this from happening? Otherwise the high setting would cause outright boil of whatever it contained. I’ve seen simmering but rarely boiling.
A space heater is usually 1500W and the low setting can be 750W or higher. So your set up is a fraction of the heat output and will heat a smaller area.
Since crock pots are made to run for hours, you are probably OK safety wise, but there was a good point that lack of liquids will make it run hotter which may cause it to fail. Leaving the lid open should help keep it cooler, as well as removing some of the rocks. Rocks can hold heat for hours and help even out the heating, but in a strict energy balance sense they help very little, only their thermal mass/inertia plays into efficiency, much like having a full fridge is more efficient then a empty one.
It does, but the thermostat is supposed to be registering the temperature of the foodstuffs in pot (or is it the crock?) and so isn’t going to be right next to the heating element. Without the pot/crock piece in place and liquids to convect around, there’s probably not going to be enough heat getting to the thermostat for it to cycle properly. Although if there were, that might make it all that much more convenient as a heater!
Hm. Not sure about the running of the crockpot ‘dry’ with just river rocks. I have used mine to humidify occasionally and it works fine. [day too warm to cook off the woodstove to use the cast iron humidifier on top, but a crockpot full of water with some cinnamon, nutmeg slices and star anise in it works like a dream and smells fantastic without overheating the room.]
I am no expert, but Years ago I found that putting a pan of hot water on the stove and raising the humidity helped take off the chill,when our furnace was broken.(One room of course).
without water you may shorten the life of the heating element as mentioned. without a fan the warm air isn’t quickly or efficiently distributed around the room.
very efficient are ceramic quartz heaters. you will feel heat from them by having the IR light they emit on your body. that type of usage is having you body out where you are within a few feet of the heater.
Probably wouldn’t want to put water in it without the crock part, which is broken in this case. But yeah, that would work with some rocks in the crock. Mini-sauna.
From the other point of view, a crock pot is typically used to keep stones warm for hot stone massage (link safe for work). Most sites seem to recommend keeping the stones damp, though. The OP’s idea isn’t as unusual as it may appear
