workshop heating

Hi all

Does anyone have practical (ie hands-on) experience of the Machine-Mart-type propane turbo heaters, aka Little Devil etc., in a workshop environment. In particular, with regard to condensation and fire-hazard (discounting the obvious like petrol tanks etc) in a workshop that is basically a barn-type building and not easy to insulate, so continuous heating is too expensive.

regards

Jim

Jim, if its a barn then the heat rises to the roof ! You need one of these long tubes that hang down from the roof that have a sucking fan at the top. This will draw down the heat and expel it across the floor so it is continually recycled.

They are available commercially and take very little fitting.

Clive

Hello JIm,

I have a couple of them that I use in the garage occasionally, but I don't think I would use them in a workshop.

They are really good heaters but as you mention, they are a pain for condensation as they raise temperature a bit too quickly, probably not a problem in a barn sort of environment.

They are 'reasonably' economical on Propane, but I only really use mine when the garage doors are open and its frosty outside.

Lofty

Hello Jim

I have used a similar product to heat my Enginering workshop in the past. They are very quick at heating up a large volume, but very expensive in gas - you need to use large cylinders.

I no longer use them as they are not allowed under my fire insurance terms, I suggest you check the small print of any policy.

I also found that if you do not have a more than adequate fresh air supply you end up with a room full of carbon monoxide, a very dangerous condition!!

You may find it better to use the diesel fueled equivalent - you can use 35sec heating fuel at approx 90 p per litre but you need to be able to store approx 400 litres to be abale to buy at this price.

adrian

Be very careful using any type of combustion to generate heat, as, to generate enough heat to be effective will consume alot of oxygen, therefore you need to ensure that there is adequate fresh supply of oxygen to permit complete combustion, the alternative is a thumping headache due to the start of CO poisoning... which leads to something alot more permanent !!! Suggest using an electric heater.

Gentemen,

My brother has recently fitted a small heat pump into his double garage/workshop, the idea is to see if it does the job and if all ok fit another. So far he is very impressed with it, it has taken the chill out of the building he reckons.

Martin P

Some years ago I used to work in a great barn of a workshop where the only heating was from 2 big red diesel fired space heaters [20Kw each perhaps]. The condensation was not good; we had to thaw the coolant tanks on the DSG lathe and big vertical mill BEFORE we were allowed to enjoy some of the direct blast to do any work!!

I wouldn't recommend them, but the comment by Clive Hartland about redistributing heat from upper levels is very relevant, sadly it was not something employed in that shed.

In my own shop, a well insulated building of single garage size inside an outer barn type structure, I use a 0.85Kw capacity storage heater run off Economy 7 night rate electricity, backed up by a small dehumidifier. Sauna it is not, but it does dispell any condensation and maintains ~12 Centigrade on most winter days. It is a lot better than the alternative of heating on demand by fan heater as well as being more cost effective.

I hope that is useful info

Brian

Just remember you are burning a hydrocarbon fuel, one of the products of combustion is Water vapour which we all wish to avoid around machinery.

Edited By KWIL on 09/12/2012 10:29:47

I suggest using an electric heater

----

I remember reading that electricity to heat is only 25% efficient

So for every 100 quid bill you get 25 quid of heat, and that's before green taxes, VAT etc are added on

Ady1

Thats the figure for the whole electricity generation process, something like 25% loss in generation, 25% overall inefficiency(steam geneation) and 25% transmission losses.

I think the figures are worse case scenario.

Best to insulate as its got no running costs.

Peter

I am involved with a .22 target shooting club, and it's hopeless trying to warm the air in our indoor 25-yard ranges at this time of year. Above the firing points, we have mounted some of the infra-red heaters you see over tables outside cafes and pubs. These don't raise the air temperature, but heat what the infra red hits, making you feel warm. They provide instant heat, or rather the illusion of heat, so don't have to be turned on beforehand to warm the ranges up for a couple of hours use, and thus prove economical in use.

I keep meaning to get one for my garage workshop, to replace the electric fan heater that's in there now.

Andy

My late father used one of these (Clarke Little Devil) to heat his garage (a single skin, block built structure with a PVC sheet pent roof) when he operated a business from home. It heated the space effectively, but was expensive to run. The problem with condensation was not noticed straight away, but after several months it was noticed that the roof was staring to sag - the roof support timbers were rotting. The roof had been up for several years before using the heater without problems, but seemed to deteriorated quite quickly when he was using the heater several hours a day, most days of the week.

After he passed away, the heater ended up with me. I used it once or twice in my block built, single skin double garage with tile roof, but the condensation build-up on machinery & motorcycles was horrendous. I now use an electric convector heater for background warmth & and an infra red electric heater for localised heating (me !).

HTH,

Nigel B.

Details of the heat pump please, Martin

I use an oil filled electric radiator in a relatively well insulated garage but if it is 5C outside it takes about four hours to raise the inside air temperature fron 6C to about 11C. Every so often I try to look for something better that won't overload the electrics without success. Also I find infrared heats not very satisfactory.

JA

Ja,

Will ask him tomorrow for info, we work together, it must be good though as he wont spend unless its 1000% perfect

Martin P

I used a space heater at one stage, found it was very noisy and fumed.

Main problem was it got to heat quickly but after you had switched it off because of the noise / fumes it seems to drop the temperature quicker than it built up.

Don't know about condensation as never kept it long enough, found the thing annoying to use.

Moved onto a massive wood burner, free heat and no condensation at all, never oil any of the machines except for where they need oil.

Been in the shop this afternoon cutting some gear blanks and temp was about 28 degrees.

Next job is to insulate the roof, just never got round to it and it'sonly single skin ply with felt on. Must loose loads of heat thru this.

John S.

I was thinking of using a small reverse cycle air conditioner as they pull moisture out of the air and can heat as well as cool .

Ian

I use one here to heat the whole house. They are very effective and about 300% efficient (3 kW heat from 1 kW electricity); However the efficiency does drop off fairly quickly below about -5 deg. _ not a problem here.

Russell.

Ahh perpetual motion, can you run your lathe off it for free as well ?

I have insulated my garage conversion (attached, single block, with roller door) with celotex aluminium backed sheeting on all walls followed by 12mm OSB, the ceiling is plasterboarded & 6" `space blanket ` .loft insulation on top of that.During the recent freezing snap it has kept the temp` around 8 - 10 deg C when the outside was down to - 2,

I have now added two electric oil filled radiators bought from my local supermarket at a cost of £19.90 ea, one placed at ea. end of the garage (17ft long), I switch them on approx 1 hr before I intend going in there & boy do they work! its usually up to approx` 18 - 20 deg.. very cosy.. when I get in. The good thing about these are that they are thermostatically controlled(as most are) so switch off when desired temp is reached, or I turn them down to suit.

I have used space heaters during my working life & although good for localised heating they will make you drowsy(CO) which is not good when you are working on machinery, therefore you will need a free flow of fresh air, or at least decent ventilation, so in some respects conversely defeats the object? so this method really needs consideration.. plus the cost of propane/diesel.

John,

Efficiency of these systems is measured 'differently' - it's the ratio of energy used to operate it to the amount 'pumped' from one place to another.

**LINK**

Neil