Fan heater warming cabinet

[jenkinsbrynmair]

Have been thinking for a while about building a honey warming cabinet from an old fridge. Hombre on here mentioned using a fan heater connected to a thermostat - anyone on here had any experience of this, or have any observations? I fancy the idea because you have the fan and heating assembly all in one - no faffing around with rigging a fan in there as well - it could be fixed on the side thus avoiding a lot of condensation issues
Another alternative I've thought of is the trusty lightbulb fittings method, but using ceramic vivarium heating elements - I assume one of these would push out the same kind of heat as a standard incandescent lightbulb?

 

[fiftyjon]

I've heard of some that use a fan heater to ripen honey in comb.

The output from the fan heater is fed up into a stack of supers, perhaps two or three high with a mesh on top. They reported that the frames need to be moved about as the reduction of the water content of the honey will vary depending on where the frame is in relation to the air flow from the heater.

They also manged to reduce the water content of some honey down to around 14%, made it difficult to extract.

 

[Hombre]

Bit bigger than a fridge for the 2kW heater model, sized to take a pallet truck and stack of pallets.

A small fan to keep the air moving and prevent hot spots is not a bad idea. I don't use a fan and find incandescent lamps can be relatively short lived. Placing two bulbs in series to half their wattage rating should work wonders for their working life.

 

[Teemore]

Two years ago I helped put together a warming cabinet using a fan heater, an old upright freezer and a thermostatic controller (one of the vivarium types - an ATC something or other purchased via E-pay) It works very well.

My own warming cabinet is made from an old fridge and is heated by a couple of light bulbs wired via a Habistat controller. I was able to retain the original fan in the fridge and have it running constantly to ensure the air circulates throughout the unit. I have a secondary thermostat in the warming cabinet that measures temperature in two different spots. This has confirmed that the temperature controller is accurate and it also allows me to manage the temperature gradient within the warming cabinet. I can move buckets etc up or down relative to the heat sources and so vary the temperature they are exposed to.

 

[drex]

JBM- I use sucha heater as you propose to keep my greenhouse frost free. Unfortunately the thermostat is not very accurate, and ability to adjust is poor. After a few days of adjustment you will think you have it set up OK, and the next day, the greenhouse has again dropped to below zero.

I use a light bulb and dimmer switch in a large fridge cabinet, with a remote digital thermometer in my warming cabinet. Sheet of metal over the bulb to disperse heat. Plenty of room for natural convection currents. No problems, but am thinking to improve it by buying one of the thermostats, as above off ebay. £5-8, I think, as my set up takes a bit of adjustment depending on outside temp on the first day.

 

[Bee-Key-Pur]

Two years ago I helped put together a warming cabinet using a fan heater, an old upright freezer and a thermostatic controller (one of the vivarium types - an ATC something or other purchased via E-pay) It works very well.

My own warming cabinet is made from an old fridge and is heated by a couple of light bulbs wired via a Habistat controller. I was able to retain the original fan in the fridge and have it running constantly to ensure the air circulates throughout the unit. I have a secondary thermostat in the warming cabinet that measures temperature in two different spots. This has confirmed that the temperature controller is accurate and it also allows me to manage the temperature gradient within the warming cabinet. I can move buckets etc up or down relative to the heat sources and so vary the temperature they are exposed to.

I use the same set up, but without the fan. I place floor tiles on the rack just above the bulbs and helps with any hot spots. I use the same warmer for wine and beer making, I have also used it to hatch out turkey eggs by adding a bowl of water, it's works very well...

 

[itma]

... mentioned using a fan heater connected to a thermostat ... I fancy the idea because you have the fan and heating assembly all in one - no faffing around with rigging a fan in there as well - it could be fixed on the side thus avoiding a lot of condensation issues
Another alternative I've thought of is the trusty lightbulb fittings method, but using ceramic vivarium heating elements - I assume one of these would push out the same kind of heat as a standard incandescent lightbulb?

Think wattage. Rate of heat input.

You probably only want somewhere under a hundred watts (depending on the size of your cabinet and its insulation (including door seals).
A fan heater is usually 1000 watts per element.

To have that running at 10% of its natural power (and carefully control between say 8.5% and 9% of output is a tricky control problem. It will tend to produce big surges in temperature.
One solution is to 'slug' it, give it a pile of bricks, tiles or bottles of water to heat, so the 'lumpiness' of the output is reduced.

Fan heater would still need a bit of rewiring - you want your thermostat to control the heat, but not the fan ...

Ex-computer, low voltage fans are very cheap and very safe.

Connect the whole lot (including any transformers) to the mains through an RCD safety plug (get a plug-through type, and use it on other things at other times).

 

[roche]

I use three of these: they are 160mm x 100mm, running at 12V and putting out about 12W each. Very gentle heat. They are controlled by an electronic thermostat, and hold the temperature of the fridge to about 32+/- 1.5

 

[itma]

I use three of these: they are 160mm x 100mm, running at 12V and putting out about 12W each. ...

Sorry, but I don't recognise what the heater element might be from.

What are they?


/ or is it a pcb that you have printed yourself?

 

[roche]

You're right - I do make them. Light bulbs aren't really made for the job, and produce a hot spot. These give a pretty even heat over a reasonable area. I quite like the facts that they don't break and are low voltage as well.