# Heating a workshop



## grumpy brit

I have a wooden workshop where I create a lot of sawdust. At the moment I am trying to heat it with a electric oil filled radiator. Not a lot of warmth in there. So, can any one advise if gas (propane ect) is safe with saw dust flying around.

Many Thanks

Colin


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## RichardG

Have a search there are quite a few threads on heating and various views. Hopefully this link works. 

Heating


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## Tony Works Wood

It's only safe if you watch where the dust or shavings land and settle, just like a wood burning stove. I've used a propane space heater before off and on for instant heat you just have to make sure the area around it is clear and also where it's pointing. When you say there's not a lot of heat is the radiator big enough for the size of the workshop and is the building insulated. I've also had another insulated workshop with an oil filled radiator left on tick over 24/7. Warm as toast and the electric bills were not big as your not heating from cold every day and your tools don't go rusty. Hope this is useful.


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## Inspector

A friend has a natural gas wall unit. Combustion air was from outside and indoor air fan circulated through the heater. No open flame. If something like that is available then it is worth considering.Kept his 800 sq ft/75m3 shop warm and toasty. 

There are wall mounted heater AC units that will work too.

You should get good dust collection not only for combustion reasons but for your lungs.

Pete


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## Ollie78

I recently bought a little ceramic fan heater from screwix. It works great and cost £35. Probably not super economical at 3kw but it gets the place warm in about an hour and then I turn it down to minimal. 

The trouble with the propane ones is they produce a lot of water.

Insulation is key my workshop is pretty good for that with 50mm celotex.

Ollie


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## JobandKnock

If combustible dust gets drawn into a propane gas heater (the type with a fan) it turns into a flame thrower, believe me. They also generate a lot of water vapour which will condense on metal tools as the building cools


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## Sideways

This may seem an odd idea but a dessicant dehumidifier makes maybe 350 or 450W of heat as a by product of drying the air. Dry air doesn't feel as cold as damp so this winter for the first time using an ecoair machine, I'm taking about 1 litre of water out of the air every 2 hrs of running and getting by with a couple of fleeces and the DH without putting the fan heater on.
Single brick garage here with no insulation, but it has been in the 6-12 degree range a lot of the time. Not minus numbers.


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## Cabinetman

It’s not the fault of the oil filled radiator, my well insulated 45‘ x 15‘ is heated very nicely with one, it’s the lack of insulation, it just can’t keep up with how fast the heat is escaping through the walls and roof. Ian


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## Westy619

I use 4 of these hooked up via thermostat and timer switch to heat my 5m x 6m workshop. They work out to less than 1Kw of power and takes a couple hours to get it up to temp (ususally around 17-19 degrees currently in winter). Key thing for me was insulation when I built the workshop, 100mm celotex under the slab, 100mm in the walls and 120mm in the roof.






RS PRO 240W Convection Tubular Heater, Wall Mounted, Unterminated Mains Lead | RS







uk.rs-online.com


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## artie

Sideways said:


> This may seem an odd idea but a dessicant dehumidifier makes maybe 350 or 450W of heat as a by product of drying the air. Dry air doesn't feel as cold as damp so this winter for the first time using an ecoair machine, I'm taking about 1 litre of water out of the air every 2 hrs of running and getting by with a couple of fleeces and the DH without putting the fan heater on.
> Single brick garage here with no insulation, but it has been in the 6-12 degree range a lot of the time. Not minus numbers.


May I ask which dehumidifier you are using?
I get less than a litre per day.


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## artie

Westy619 said:


> They work out to less than 1Kw of power and takes a couple hours to get it up to temp (ususally around 17-19 degrees currently in winter).


I wouldn't want my workshop that warm.
I'm quite comfortable down to about 8c.
If it goes below that I fire up one of those cheap diesel heaters that people use in camper vans.
I have a line through the wall to the CH oil tank so it's very cheap to run.
My "shap" isn't well insulated so this just raises the temp a few degrees. In a well insulated shop it would of course be much more effective.


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## Sideways

artie said:


> May I ask which dehumidifier you are using?
> I get less than a litre per day.


It is an ecoair dd3 classic mk2. Bought direct from the makers.
4.5l tank.
In the last week I ran it 3 times on the 2hour timer, full speed.
Humidity display showed it dropping the RH by about 12% each time
96 to 84, 86 to 74, 78 to 66 sort of numbers.
I poured 4 litres down the sink at the end of those 6 hours. The water container felt heavy.


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## Cabinetman

Fairly sure that’s the same one I have, I run it in a large wardrobe type construction (I call it my kiln) to reduce the moisture in firewood it’s staggering the amount of water that comes out, and as you may know it don’t burn!


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## Rufus

I have a Clarke Little Devil propane heater but, as someone said above, they generate a lot of water vapour into the room which then condenses so I don't use it in my workshop. I now have a desiccating dehumidifier (Meaco DD8L - very good, takes a lot of moisture out and also slightly warms) and alongside that a ceramic heather. Not sure what temperature I get up to, but it's comfortable enough to work and the dried air makes it feel better.


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## Tony Works Wood

Cabinetman said:


> It’s not the fault of the oil filled radiator, my well insulated 45‘ x 15‘ is heated very nicely with one, it’s the lack of insulation, it just can’t keep up with how fast the heat is escaping through the walls and roof. Ian


Your exactly spot on Ian. You don't really notice the electric it uses either as it's not on full trying to catch up heating a cold space every working day etc.


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## Tony Works Wood

Ollie78 said:


> I recently bought a little ceramic fan heater from screwix. It works great and cost £35. Probably not super economical at 3kw but it gets the place warm in about an hour and then I turn it down to minimal.
> 
> The trouble with the propane ones is they produce a lot of water.
> 
> Insulation is key my workshop is pretty good for that with 50mm celotex.
> 
> Ollie


50Mmm Celotex wow. I have 12mm Celotex and its as warm as toast inside.


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## Terrytpot

Got very excited over the weekend as I’m currently selling up and looking to move home to anywhere that’s not here and stumbled over something in budget with what looks like a potential workshop where that won’t be an issue…the first picture is looking from the end of the garden back upto the house and on its left, it’s slightly modified garage complete with boiler and central heating,oh and full size snooker table!


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## John Brown

Two points. Firstly, all electric heating is effectively 100% efficient. Think about it, how would the wasted energy be.manifested? It may be that some types of electric heating offer tighter control of temperature, with less overshoot. That can help with economy. Another possibility is to use radiant heating, which can make you warmer, but doesn't help much with big lumps of cold metal.

Secondly, it's never cheaper to leave heating on all the time, as apposed to when it's needed. It may be more convenient, but it won't be cheaper. The loss of energy is proportional to the temperature difference. I know a lot of people will tell you both these are wrong, but it's basic physics.


Insulation is your man.


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## jcassidy

+1 for an insulated shed and oil filled radiator. I got one with an integrated fan so the air circulates. I was using a heater but worried about dust getting in and igniting on an element.


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## artie

Terrytpot said:


> Got very excited over the weekend as I’m currently selling up and looking to move home to anywhere that’s not here and stumbled over something in budget with what looks like a potential workshop where that won’t be an issue…the first picture is looking from the end of the garden back upto the house and on its left, it’s slightly modified garage complete with boiler and central heating,oh and full size snooker table!


Twas always something I dreamed of, to have even a pool table at home.

Now when it is within sight of becoming possible, my eyesight is not so sharp as it was.


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## Keith 66

Terrytpot said:


> Got very excited over the weekend as I’m currently selling up and looking to move home to anywhere that’s not here and stumbled over something in budget with what looks like a potential workshop where that won’t be an issue…the first picture is looking from the end of the garden back upto the house and on its left, it’s slightly modified garage complete with boiler and central heating,oh and full size snooker table!



Stick a nice thick top on that table & a few vices & you are good to go!


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## Terrytpot

Keith 66 said:


> Stick a nice thick top on that table & a few vices & you are good to go!


 I was thinking with some strategically drilled holes it’d make a nice mft table..  hmm,maybe with a bit of a wedge under one end it would then be good for bar billiards too…decisions,decision’s ..


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## hairy

artie said:


> Twas always something I dreamed of, to have even a pool table at home.
> Now when it is within sight of becoming possible, my eyesight is not so sharp as it was.



Smaller is more obtainable


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## Spectric

John Brown said:


> Two points. Firstly, all electric heating is effectively 100% efficient.


Tell that to people with night storage heaters. It may well be capable of near 100% efficiency but that also means 100% consumption of Kw/hours so you need some form of thermal mass. An oil storage heater will consume less energy because it does not need to run continously once it has reached the thermostat setting, it will just keep switching on periodically to keep the oil hot.


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## Terry - Somerset

The heating power required must depend on the size of the workshop, the extent of insulation/heat loss, ambient air temperatures, and desirable working temperature.

My own solution for brick single garage, flat largely uninsulated roof, in the south west, is a 3KW fan heater powered through a 20 minute timer. 

If it is cold when I go in I switch the heater on, it automatically goes off 20 minutes later. If I notice I am getting cold again (physical movement and other machines create heat) then it goes on again.

It is a cheap solution - cost of heater and timer <£30, only powered up if I feel cold.


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## artie

hairy said:


> Smaller is more obtainable


6 by 4 is my minimum desired.

I'm trying to get up enough courage to retire mid year. and if I do, I can convert the workshop to a leisure/games room.


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## John Brown

Spectric said:


> Tell that to people with night storage heaters. It may well be capable of near 100% efficiency but that also means 100% consumption of Kw/hours so you need some form of thermal mass. An oil storage heater will consume less energy because it does not need to run continously once it has reached the thermostat setting, it will just keep switching on periodically to keep the oil hot.


I'm sorry, but I have no idea what point you are trying to make. Night storage heaters are exactly as efficient at converting electricity into heat as are oil filled radiators. One may be cheaper to run than the other, depending on electricity tariffs, and one may be less convenient, or unsuitable, or difficult to control, but that's not what I was talking about.


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## Dave Moore

grumpy brit said:


> I have a wooden workshop where I create a lot of sawdust. At the moment I am trying to heat it with a electric oil filled radiator. Not a lot of warmth in there. So, can any one advise if gas (propane ect) is safe with saw dust flying around.
> 
> Many Thanks
> 
> Colin


Look at these. Diesel but only hot air exchange. FlowerW Upgraded Diesel Air Heater Parking Heater, 5KW 12V All in One Diesel Fuel Heater with Four Air Outlets for Car RV Boats Bus Caravan and More boosted : Amazon.co.uk: Automotive


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## artie

Dave Moore said:


> Look at these. Diesel but only hot air exchange. FlowerW Upgraded Diesel Air Heater Parking Heater, 5KW 12V All in One Diesel Fuel Heater with Four Air Outlets for Car RV Boats Bus Caravan and More boosted : Amazon.co.uk: Automotive


That's almost the same as the one I use.

Sad to see they have almost doubled in price in a little over a year.


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## artie

John Brown said:


> Two points. Firstly, all electric heating is effectively 100% efficient. Think about it, how would the wasted energy be.manifested?


I'll go along with that.
The downside is although you're getting 100% that 100% is expensive it may be cost effective to use a less efficient power source which is cheaper.


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## Lazurus

Insulation has to be your friend, I have an 8m x 5m brick and block workshop 50 mm cavity bats, flat roof and not insulated and 75mm polystyrene under the concrete slab floor. I have a single oil filled rad on in winter and keeps it a pleasant 17 degrees. I could have put more insulation in by making the cavities bigger but wanted as much room inside a possible. If I ever insulate the roof that can only improve the situation


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## Bingy man

John Brown said:


> Two points. Firstly, all electric heating is effectively 100% efficient. Think about it, how would the wasted energy be.manifested? It may be that some types of electric heating offer tighter control of temperature, with less overshoot. That can help with economy. Another possibility is to use radiant heating, which can make you warmer, but doesn't help much with big lumps of cold metal.
> 
> Secondly, it's never cheaper to leave heating on all the time, as apposed to when it's needed. It may be more convenient, but it won't be cheaper. The loss of energy is proportional to the temperature difference. I know a lot of people will tell you both these are wrong, but it's basic physics.
> 
> 
> Insulation is your man.


I’ve been a gas engineer for over 30 years and I’ve lost count of how many customers would leave their heating on all day and say it’s cheaper-this was mainly due to large inefficient boilers with equally inefficient systems and over / undersized radiators etc. the time to bring the home up to 21deg Was ridiculously long and of course expensive. with the ever increasing cost of energy it’s impractical to do this in today’s world so I fully agree that up to date insulation in walls loft and of course double or triple glazing is the way forward. With the current A rated boilers and modern smart controls there is no reason to heat an empty home . However coming home to a cold house is also a bad idea so it’s worth investing in a smart thermostat like hive or nest -simply turn on heating before you leave work via the internet and by the time you get home it’s warm and you’re not wasting energy-as for garages converted to workshops then it’s better if possible to add extra radiators via your home c h boiler ( better still it can be zoned off to work independently to the main system ( house)


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## John Brown

Even with gas, it can never be cheaper(assuming a constant tariff) to leave the heating on permanently.


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## Sandyn

I got a battery powered heated Gilet for a Christmas present. It is fantastic. It works really well. The best thing about it is the heating elements at the back of the collar. It came with a 10Ah battery which will run for about 5-6 hours on the mid setting. It doesn't keep hands warm, but I think the jacket type may be better for that. I preferred the gilet style for working in the workshop.


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## John Brown

Sandyn said:


> I got a battery powered heated Gilet for a Christmas present. It is fantastic. It works really well. The best thing about it is the heating elements at the back of the collar. It came with a 10Ah battery which will run for about 5-6 hours on the mid setting. It doesn't keep hands warm, but I think the jacket type may be better for that. I preferred the gilet style for working in the workshop.


They sound like a great idea. Except for the collar. Half the members of this forum get hot under the collar without electrical assistance.


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## DennisCA

I will be replacing my oil filled radiator with an air-air heat pump.


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## DennisCA

artie said:


> I'll go along with that.
> The downside is although you're getting 100% that 100% is expensive it may be cost effective to use a less efficient power source which is cheaper.



A heat pump is over 100% efficient and no that's not a thermodynamic violation, because it does not create the heat from the electricity used. Instead it uses electricity to move ambient heat from the environment through the 'magic' of the refrigeration cycle. So using a heat pump it can 'produce' between 2 - 5 times more heat than you would have gotten using direct electric, depending on the outdoor temperature.


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## artie

DennisCA said:


> So using a heat pump it *can* 'produce' between 2 - 5 times more heat than you would have gotten using direct electric, depending on the outdoor temperature.


I'm far from an expert in heat pumps, but my understanding is that, as you say, in certain circumstances, it *can* 'produce' between 2 - 5 times more heat than you would have gotten using direct electric.

In other circumstances it *can* 'produce' 1.1 times or less the heat than you would have gotten using direct electric.

It would be great if the former circumstances greatly outweighed the latter, alas on these islands in winter I think not.


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## TRITON

JobandKnock said:


> If combustible dust gets drawn into a propane gas heater (the type with a fan) it turns into a flame thrower


Ooooo thats worth experimenting


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## DennisCA

artie said:


> I'm far from an expert in heat pumps, but my understanding is that, as you say, in certain circumstances, it *can* 'produce' between 2 - 5 times more heat than you would have gotten using direct electric.
> 
> In other circumstances it *can* 'produce' 1.1 times or less the heat than you would have gotten using direct electric.
> 
> It would be great if the former circumstances greatly outweighed the latter, alas on these islands in winter I think not.



Your winters are actually quite mild from my perspective so they should be able to work year around with a high COP. You don't get down to a COP of 1 until you get to -20C with heat pumps here made in the last 10 years (at least in the nordic market, I know the US market has lagged behind for a long time for instance). Heat pumps are a very popular heating solution in the nordic countries (the most popular perhaps) so I can't think they would have any problems in the UK winters.


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## artie

DennisCA said:


> Your winters are actually quite mild from my perspective so they should be able to work year around with a high COP. You don't get down to a COP of 1 until you get to -20C with heat pumps here made in the last 10 years (at least in the nordic market, I know the US market has lagged behind for a long time for instance). Heat pumps are a very popular heating solution in the nordic countries (the most popular perhaps) so I can't think they would have any problems in the UK winters.


It's probably about 10 years since I did some research on them.

I noticed recently that HM Government are pushing them so automatically assumed they're useless. 

If I get my net connection fixed soon I'll have another look.


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## DBC

My workshop is a rented unit in a business park. It is a large unit and 5m high under the ridge. And unheated. A couple of weeks a year I daydream about heating it. Then I get brought down to earth by one of two thoughts. The first is the cost. The second is the voices of the guys who taught me my trade - these voices are inside my head as their owners are long dead - telling me what a wimp I am and if I am that cold I should be working harder. How it is possible to work harder when I am hampered by so much clothing that I look like the Michelin Man escapes me. Maybe a heated workshop then if I win the lottery; even then the voices will probably forbid it.

My solace is that that my mate in the adjacent workshop has a couple of his corrugated iron sheets replaced by clear plastic sheeting in his roof. He is always a degree or two colder than me. A couple of days a year he has ice on the inside of his windows also.Teasing him about this somehow makes me feel a little warmer.


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## John Brown

Heat pumps may be fine for new builds, but a lot of older properties have heating systems designed to run at higher water temperatures, and would need much larger radiators installed, which is often not feasible. Also, electricity is so much more expensive than gas that even with a COP of 4, it'd still cost more to heat the house than with a gas boiler. So with the initial outlay and increased running costs, it's hard to imagine householders being in any hurry to convert.


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## Jacob

Woodwork shop - woodburner. Get the right one and it will do sawdust as well. If you do enough volume you can heat the house too.
And it solves waste disposal problem. 
As energy prices go higher this is likely to become first choice.


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## DBC

Jacob said:


> Woodwork shop - woodburner. Get the right one and it will do sawdust as well. If you do enough volume you can heat the house too.
> And it solves waste disposal problem.
> As energy prices go higher this is likely to become first choice.


Great idea. Unfortunately in the 90s a motor rewinder had a fire in his unit in the complex where I am currently. Since then no woodburners is in the tenancy agreement.


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## HamsterJam

Our local motor mechanic uses the old engine oil from servicing cars to heat his workshop. It’s negative cost as he would otherwise have to pay a disposal company to collect it. 
Often wondered how much the heaters cost and whether he has any spare oil.


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## DennisCA

John Brown said:


> Heat pumps may be fine for new builds, but a lot of older properties have heating systems designed to run at higher water temperatures, and would need much larger radiators installed, which is often not feasible. Also, electricity is so much more expensive than gas that even with a COP of 4, it'd still cost more to heat the house than with a gas boiler. So with the initial outlay and increased running costs, it's hard to imagine householders being in any hurry to convert.



Talking about air to air for this purpose so no plumbing to consider, and there was talk about using direct electric, and in comparison to that, it's not even a question of what to choose. Does the UK have very expensive electricity or very cheap gas? I pay about 8 cents per kWh.

edit: That's the higest rate in years for me, usually varies between 3-5 cents.


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## Inspector

DennisCA said:


> Talking about air to air for this purpose so no plumbing to consider, and there was talk about using direct electric, and in comparison to that, it's not even a question of what to choose. Does the UK have very expensive electricity or very cheap gas? I pay about 8 cents per kWh.
> 
> edit: That's the higest rate in years for me, usually varies between 3-5 cents.



Dennis you have no idea of how good you have it. I'm charged a monthly fee of $32.90Cad just to be hooked up and $0.142Cad kW.h with "carbon tax" of $0.0064Cad kW.h added to that.  That is why we heat with natural gas. Too cold in the winter here to rely on an air to air heat pump with out a supplemental heating system. If I were building new or retrofitting a house I planned on living in for a long time I would put in a ground source heat pump.

I'll add there are provinces here where the electrical costs are a lot higher too.

Pete


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## DennisCA

A ground source heat pump is how I heat the main house too, with a 1.4 ton masonry heater for additional warmth.


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## g1_lo

DBC said:


> Great idea. Unfortunately in the 90s a motor rewinder had a fire in his unit in the complex where I am currently. Since then no woodburners is in the tenancy agreement.


have you thought about indemnifying yourself with your insurer so that your landlord would allow you to have one. They will only be concerned about their downside and if you can get this setup then you'll be more productive.


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## mollydog

I’m in the process of having my log timber garage/workshop being built, a 6M x 6M, for heating I bought one of those Chinese diesel heaters, and purchased a 45 gallon drum of red diesel, 

When the heater arrived I tested it out


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## DrDarren

I’m not sure if ‘re-igniting’ this thread is good form or not. I’m persuaded of the oil-filled radiator approach for my tiny shop. 8.10’. I’m in Scotland and the shop is well-ventilated (see roof pics attached) and I wonder if there’s any point to radiator as I imagine I’d lose all the heat or is the benefit the continual flow of air through the shop? Any thoughts appreciated for a hand tool (mostly) hacker. My partner affectionately calls my style ‘robusta’.


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