Thread: shed heating

Probably because I'm just too well padded it never seems to get cold enough to worry about heating. We only used some heating in the house last year on the days when we sit the grandson. The house itself got down to 14º last year and some visitors did comment on how cold it was but we love it. Some mornings its <5º inside the shed but even that does not worry me. If I ever had a heating problem I'd just fire up my mains gas forge which can develop up to 22kW/hr of heat most of which goes out the exhaust fans but the radiant heat can heat the inside of the shed to 40º running it for just half an hour or so.

Hi Dave . I'm thinking the same way as its getting colder . I'm wanting to build a heater . I had a nice wood heater in the city workshop which now heats our house . An Aussie made Nectar Mk 2 . Great heater ! Id love the same for the workshop but not the cost of buying it .

My plan is to cut and weld up a heater using some wide diameter pipe I have here . Ive got about 4 meters of 7 or 800 diameter 4mm thick wall pipe.
I want a heater that can be well loaded with wood. That also has a special feature of being able to heat metal with a forge built into the bottom . As a bit of a hobby blacksmith I constantly found myself using the wood heater at the old workshop when ever the hot charcoal was well built up and I needed to bend or heat treat an edge. It worked ok for that but was very limited with the opening not being suited for anything but the end of piece , and no air and fire control . So if I can build those features in it may work. The forge will just be a pipe arrangement coming up through the bottom to a Brake disk bowl that can sit in the bed of ash full of ash until I need it . It will be directly under the flue . A small blower like an old hair dryer will do for the air for that.

As well as heating and bending some steel using the by product of heating the workshop I wouldn't mind trying some casting using zinc . There should be no problem getting the heat needed for that as well I think .

As for the heating of the workshop side . Ive been studying my heater in the house . I need air control for the fire which will be vents through the door I think , and a baffle plate above the fire that is adjustable , it needs to be shoved out of the way for the forge to work . A baffle plate is needed so the heater box above the fire doesn't burn out the metal above the fire , it takes the brunt of the fire and sends it around the sides and you replace the baffle plate every few years. As well I need fire bricks or just red bricks to line the wall where the fire will sit as well so it doesn't burn out there .

I'm a bit stuck on how to vent curved doors atm . I can see a way with lots of holes and a sliding plate but it looks time consuming . And I think Ill have to build the whole heater so it comes apart for adjustment with the Oxy torch and welder if its not working right as well .

The colder it gets the more Ive been sketching ideas. Ill have to start cutting steel soon . Ill post some pics in a thread here.

Round cylinders are a bit harder to vent and add doors to than square boxes it seems.
I think if you want to use a Gas cylinder the problems are similar to mine in that you have to vent it for air flow to the fire and a baffle plate is a good thing as well , not just for the burnout thing but maybe to direct the less intense heat around the sides a bit . And also bricks or fire bricks to hold the hottest part of the fire off the walls. That's if you want a long lasting heater. I'm sure you could also do without some of this and get warm fast and find the cylinder may last 3 or 4 years ? Depending on how hot you run it ? If you find you get hot glowing parts in mild steel you will get some distortion and also some probability of burn out in that area.

I'm just trying to figure all this out myself so I may be wrong on these details so just throwing my thoughts in on this .

Rob

I'm reading about dust collection at the moment, that if you're not venting huge amounts of air outside with a 3hp machine through 6" hoses, you're basically doing it wrong. And that it's also recommended to use big fan(s) with open doors when doing anything that creates wood dust, which is basically nearly everything.

So how does that reconcile with keeping a shed warm?

Following.

This is my second year using an inverter aircon. It is 500% absolutely fantastic. It's a Samsung and has a KWh readout. All up it was $1300 to put in.

It both heats and cools a 8x5m shed. Only the "top half" of 3x5m is heavily insulated. The lower half is a plain tin roof with sagging sarking. The glass in the windows is ancient, cheap and incredibly thin.

Despite this horrific inefficiency, the cost of running the unit is tiny. Last night it was 1 degree and the day only 12, yet the unit kept the whole area at a rock solid 19 degrees. For 18 hours of running the readout said it used only 8 KWh of power. I pay 18.8 cents per KWh.

Over the summer and winter it gets very hot (40) and cold (-8) in Canberra.... So it's done well.

Obviously I need to insulate the roof in the lower part, but the manner the roof is held up on one side precludes using batts and plasterboard. It would be good to have some sort of light weight foam that can be adhered to the underside of the tin roof.

I'd be happy to read how others insulate their tin sheds.

Originally Posted by Spyro

I'm reading about dust collection at the moment, that if you're not venting huge amounts of air outside with a 3hp machine through 6" hoses, you're basically doing it wrong. And that it's also recommended to use big fan(s) with open doors when doing anything that creates wood dust, which is basically nearly everything.

So how does that reconcile with keeping a shed warm?

yep its a problem, i'll just have to live with the warm air going out the door when i am machining,then put the off cuts in the fire. Are you reading Bill Pentz on dust collection? its a pity clearview is SO expensive here in Australia. Why do so many dust collectors have two 4" port when the best way is, as you say running 6" lines to machinery where the manufacturer has 4" ports its a pain. How did they determine 4" was best and effective for dust and chip collection? i could go on about this dust extraction topic but its done my head in before. got me!!! i'd like to see a test between the carba-tec cyclones and clearview.

Originally Posted by dave_c

Are you reading Bill Pentz on dust collection?

Ι am, and I'm not gonna lie, it's made me seriously consider giving up woodworking. DC is a necessary but massive investment in time, effort, space, money, just to stay safe and healthy.

Originally Posted by dave_c

Wondering what others do for heating in their man caves? a picture would be nice.

I am actually moving in a couple of weeks so I will have a new shed.It looks like this. Note that the shed is bigger than the house - as it should be.

shed1.jpgshed.jpg

To explain the photos, The right hand end was the original 6 x 6 metre garage. Later they built a 6 x 6 metre carport in front of the garage and three metres away. Sometime later they built in the sides of the carport and joined the carport to the shed with a roof and the wall on the opposite side, but left the three metre gap you can see in the photo. The overhead photo shows this too.

The front of the original shed has a half width rolladoor and a pedestrian door in the front as shown here in the picture which was taken before the carport was enclosed and the open area covered.

shed2.jpg

So from a heating perspective, I like the potential of this. I have a fully enclosed 6 x 6 metre shed that I can heat, where I can put my workbench for handtool work and other machines that are needed for joinery etc like the router table, drill press and possibly the metal lathe and milling machine. It should be fairly economical to keep that part warm. Dust extraction should be fairly effective with a modified 2hp system and my room air filter. When the weather is warm, I can open the rolladoor. There is also a similar sized rolladoor on the same side inthe back wall of the shed so I can get some flow through ventilation on the hotter days.

The remainder of the shed (9 x 6 metres - as big as my current shed) can be used for timber storage and big machines for breaking down stock like 21 inch bandsaw, tablesaw, sanders, wood lathes and other messy things (yes I know the router table will be messy and I said it would go inside the "cleaner" area) and I can pick and choose the better days to work out there in the cold.

I have enjoyed my current workshop but I think there is a lot of potential for the new one,particularly in relation to heating.

Hi from NZ. Im in the Sth Is and it can get pretty cold here. Maybe a max' of 3 to 5 days of snow on the ground but mostly big frosts. I used to try to heat a double garage which was used as my "man cave" but the roller doors didn't seal along the top so it was pointless thinking that I'd be able to keep warm with reasonable cost incurred.
I looked at fires but shied away from that, mainly because of the dust factor.
I ended up just using a couple of small 1000 watt fan heaters which I had positioned where I was most often standing.
Then the quake happened and lost the house we moved to a semi rural rental and I lost all sheds. I then bought 3 X 40ft insulated shipping containers and decked them out with 17 or 19mm ply flooring.
One came with a large window in it plus a hole for a door, to gain access into a smaller 20Ft insulated job, next door.
I how have a small cast iron fire which is about the same size as a railway guards wagon/caboose used to have.
When I say small, it would only take about 6 pine cones to fill the fire box.
I repair coal ranges and old fires like the one I have keeping the volume of the container warm. It works a treat. And very economical on firewood.
An acquaintance makes small fires which are very cleaver. Basically, its about a 8" steel box section. He's welded a heavy top plate to the top and then welds a cut-away section of about a 4" pipe for the flue to get attached to. I dont see his web site but its similar to this one in the Link http://www.littlecracker.co.nz/
There is a lot of science in the design work of an efficient fire.
An excellent book to find the most important points is... "JAY SHELTON"S SOLID FUELS ENCYCLOPEDIA". ISBN 0-88266-307-0
I refer to it often.

If you have a large 2 or 3 bay garage sized area, I suggest looking for something that is cast iron & is enclosed. Maybe something like an old ESSE Dura.
I like the closed fires 'cause once the fire is going, you can latch the door to make it safer from a possible dust explosion.
You could also feed air to it, via a large diameter tube, directly from the outside environment, to the fires air intake orifice.

Best wishes to yee

I have split LG units for my home and I had a spare port on the compressor which happens to sit outside of my shop. I ended up putting a 12,000 LG BTU head in the shop. It works for both heat and air conditioning. I have to clean the filter fairly religiously, but it works great. My dust collection is a Oneida Cyclone located in a corner of the shop. It does not vent to the outside.

Originally Posted by Spyro

I'm reading about dust collection at the moment, that if you're not venting huge amounts of air outside with a 3hp machine through 6" hoses, you're basically doing it wrong. And that it's also recommended to use big fan(s) with open doors when doing anything that creates wood dust, which is basically nearly everything.

So how does that reconcile with keeping a shed warm?

It doesn't, and anyone that shuts themselves inside their sheds for warmth or coolth with DC venting inside sheds with appropriate precautions are just fooling themselves.

If you "have to" do this you should seriously consider using a negative pressure system which has the impeller after the dust collection and then uses high quality filters such as the Nanofilters used on the Clearvue.
This reduces a little the effect of fine dust leakage from the positive pressure side of the DC back into the shed.

But this cannot be achieved using "budget" negative pressure systems such as cyclones and chip collectors on small DCs because the cyclone/chip collector will severely restrict air flow so much that it will not collect the fine dust in the first place place. That's the reason these systems show so little fine dust collected by filters.

I've shown this picture a few times but now might be the time to show it again.
This is 270 mg of fine dust. Suspended in air it sufficient to contaminate a ~100m^2 shed to above the current OHS limit.
This limit does not take into account the added toxicity of Australian timbers of that Seniors and folks with any sort of health conditions should be working at much lower levels.

Unless you have a dust particle counter and know how to use it then unfortunately you have little choice in going for overkill with dust extraction. Dust (not just wood dust) is now the fifth leading cause of death in the world and its not just breathing related but like to all cardiovascular diseases.
Wooddust.jpg

My problem is not heating but cooling.

In summer I try to plan to perform dust activities in the mornings but if I have use the DC I turn off the AC and just use the dust collection. Then if it is really hot I turn the AC back on and go have an iced coffee up in the cool house. Even on a 40ºC day at 42m^2 my well insulated shed is cooled back down enough to survive in about 20 minutes. In the afternoons I usually undertake repairs, sharpening, assembly, tidying up etc so that the use of the DC is minimised.

If you have to be able to use your DC at a moments notice you simply don't have enough different projects on the boil you can swing onto.

One more tip, consider locating your internally venting DC near (but not too close) to your fire - that way some of the excess dusty air might at least go up the chimney

Very few Clearvues or any other DE's vent to atmosphere in the US, they all rely on filters to recirculate the air so if you want to see the best or worst practises look there.

Originally Posted by BobL

One more tip, consider locating your internally venting DC near (but not too close) to your fire - that way some of the excess dusty air might at least go up the chimney

Hi Bob, are you feeling ok? I am a bit worried about you.

You introduced a new idea about dust management - using the phrase "might at least" - and no scientific data, instrument readings, graphs or charts to back it up.

Originally Posted by doug3030

Hi Bob, are you feeling ok? I am a bit worried about you.

You introduced a new idea about dust management - using the phrase "might at least" - and no scientific data, instrument readings, graphs or charts to back it up.

Got to throw the wild cards in every now and then.

To heat a shed in winter, you buy one of these (or more, depending on where you stand & work): https://www.bunnings.com.au/heatstri...eater_p3170733 - more info here: https://2ecffd01e1ab3e9383f0-07db7b9...2b5568a9f9.pdf

These will keep YOU warm, not the ambient air and everything else around it. These work completely differently than a normal heater - I won't pretend to fully understand them, but you stand under it and it feels nice and warm.

I suspect this would be true even if you have the dusty running and venting outside.