Honey Warming Cabinet

After extracting honey it needs to be 'ripened'. This means kept at a little under 40 degrees Celcius so any bits of bee or hive relate detrius and air bubbles trapped in it can rise to the top, it also makes the honey easier to decant into jars. So far I've done this by leaving my buckets of honey for a week or so in the airing cupboard. It kind of works but doesn't really give you that much control of temperature and I doubt comes close to the temperature I'd prefer. What's needed is a Warming Cabinet. Like the name suggests it's just a cabinet that keeps the contents warm. They're readily available and if you have £180 burning a hole in your pocket you can have one delivered, or for a lot more have one custom made. However they're actually relatively easy to make, you just need an insulated box, a heat source and some kind of temperature control. Most homes in the UK have an insulated cabinet or two in the form of a fridge or freezer.

One recent November Sunday whilst heading to Pave for a latte with my new housemate, Beth, I spotted a small fridge lying face down on the pavement. After dark we popped back out with my trusty Black & Decker Tough Truck in tow -well actually I was carrying it rather than towing it because those tiny wheels make quite a racket on pavement. We located the prone unit, hoiked it onto the trolley and rolled it home accompanied by gentle roar of stupidly small wheels.

Fridgemaster MRTZ98/1. Grotty version.

Turned out it wasn't a fridge at all but a freezer. A confusingly named Fridgemaster MTRZ98/1 freezer to be precise. Does it matter? Yes. Why? The shelves in this unit are made up of metal tubing that forms part of the cooling system. Freezers and fridges use some pretty nasty gases in their cooling systems. Whilst Freon is no longer used it's quite likely this freezer used HFC-23 or Isobutane as a coolant. HFC-23 is a major greenhouse gas and I'm fairly certain that if someome released a freezerful of the stuff into the environment and then wrote about it in a blog complete with photographs they'ed be looking at a hefty fine, assuming the powers that be are doing their job for a change. Isobutane on the other hand isn't as bad for the environment but it is very explosive, and when it's not being used as a coolant makes a good propellant too.

Tubey shelves. Could be a problem.

Looks a bit grotty inside too.

Whilst pondering how I was going to remove the shelves without releasing the coolant I had a look at the rear of the freezer and discovered I didn't really need to worry about it at all because some idiot had already cut the compressor from the back of the unit releasing whatever coolant was in there out into the street. So whilst scrap metal tatters bring us a few litres of greenhouse gas closer to climate change apocalypse or random explosions there was one less thing for me to worry about. Shame the planet's in such a mess but whilst people prioritise pocketing a little profit over maintaining the fragile ecosystem that keeps them alive we're doomed.

Crime scene :-o

Having ascertained there was no coolant to worry about I started chopping out the shelves. I'd lent a mate my hand axe so wound up using the blunt edge of a machete to buckle the shelves so I could drag them out and hacksaw the two tubes off where they entered the back of the unit. The step at the bottom of the freezer where the compressor and other absent gubbins had been housed meant I couldn't just stand my honey buckets on there. One way round that was to turn the freezer upside down which would've been fine but it looked a bit tatty, well okay more tatty that a disused freezer hauled in off the street normally looks I mean, or to lay the unit on it's back so the back wall became the floor and the door a lid. Less vertical space would've probably made it easier to acheive a uniform heat within the unit too, but there wasn't room in my outbuilding to store it like that -too much bulky beekeeping stuff taking up space. I opted to cut free the bottom shelf and put that back in place to stand the buckets on. The heat source will go in the space below that.

Rocket science this is not.

Having got a fairly well insulated box to use I next needed a heating element. There's plenty of cheap and readily availabe heatsources around in the form of lightbulbs. Energy saving bulbs are currently ousting the old energy inefficient ones that make good heatsources but I'm fairly sure it'll be a while before I can't find any. I was planning to use a 40W bulb but the closest I could find in my local Sainsburys 24hour shoppe was a 42W bulb giving the equivalent of 50W light. I figured that should still work.

If I was to attach a bulb to a power suplpy, turn it on and leave it in a closed plastic freezer I don't really know how hot it would get and I don't want to start a fire or damage the honey so I needed to add some kind of heat controller. There's a few options people use for these including aquarium and immersion heater thermostats, I opted for a room thermostat as unlike the other two it's intended to read air temperature rather than liquid temperature. A lot of room thermostats only go up to 30 degrees which is a little low for what I need but a little searching on fleaBay I was able to find a Towerstat branded one that appears to go up to 40 degrees. I attached a baynet bulb socket I had sat in a toolbox for years and the flex from my tragically deceased coffee machine. I then had a rethink and decided to add a second lightbulb to speed things up a bit. The lights will be turned on till the thermostat reaches the desired temperature at which point they'll be turned off again till it drops and the thermostat reactivates them.

Heat sources and temperature controller

With a pair of light bulbs sat there kicking out heat there would be a pretty uneven heat distribution within the cabinet (I've stopped calling it a freezer now) so there needs to be some sort of airflow within the cabinet to mix it up a little. I added a couple of old 80mm computer fans attached to the 12V transformer from an old Netgear Wireless N access point.

They're not my biggest fans

The plan was pretty simple, drill a hole throught the freezer side, push a cable through and attach a two way adapter inside the cabinet and put a plug on the outside end. Plug the bulbs and fans into the two way. I didn't have a two way socket adapter knocking about so used a three way instead. I used some No-More-Nails type glue to attach the thermostat to the freezer wall as well as the three way and used a few nails to fix the bulbs to a wooden block from a pallett I'd liberated from a skipsome time ago. The fans were cable tied to the shelf with the left one moving air up and the right one moving air down.

All the gubbins in place.

Whilst I'm no physicist the fan placement and orientation should keep the air moving in a more or less clockwise flow and stop hot spots developing near the bulbs. After a little reshuffling of the outbuilding contents I was able to find a place for the cabinet to live, then I cut the cable from the back to the right length to reach the socket and attached a plug. The warming cabinet was complete and just needed testing. I turned it on set a temperature, watched the lights go on and heard the fans whirr. The important bits seeemd to be working, I just needed to check it'd reach and maintain a target temperature. Setting it to the thermostat's highest temperature I took an Indoor/Outdoor Thermometer, popped the probe into the freezer, closed the door and sat the digital bit on the top. I then went inside and made a Latté with my replacement coffee machine, a Cookworks Espresso Coffee Machine, this is probably the slowest coffee machine in the world. You could make brew and drink a cup of tea in the time it takes this machine to make a frothy coffee, hell you could probably go to India and pick the leaves yourself if you fancied travelling. After my coffee break I went out and checked the thermometer. It was 39.5 degrees Celcius in the cabinet and about 7.5 degrees outside. Success. I turned it off unplugged it and propped the door open in case the glue I've used outgasses as it cures.

It'll work even better with that door closed

One more bulky item added to my beekeeping inventory. As I already had most of the parts lying about or picked them up for free in my travels the whole thing cost me well under a tenner. Probably won't need it till September 2013 at the earliest.