Best Heating Option For Your Hobby Shed

[Martin Harris - Moderator]

Wouldn't 13.2V be a suitable (minimum) float charge for an old car battery? Just run it on the mains supply and thebattery will take on the load should you get a power outage. The battery might benefit from a very occasional top up charge but that could be done at any suitable time.

[Graham R]

Thanks Martin, would it be safe then to connect a 13.2v supply direct to a 12v battery and then the heater to the battery as well, or does it need to be a proper regulated charger.?

[Martin Harris - Moderator]

I don't see a need for anything other than that as I assume it's a well regulated and smoothed supply. In effect, it's like running your car on a long trip - except the regulator on that will be set at a higher voltage - so the battery will not be overcharged - in fact at 13.2V it won't even get to full charge.

I'm not an expert on any of this although it seems little different to float charging telephone exchange batteries which I did know a little about so feel free to ask for other opinions.

[Martin McIntosh]

Don`t worry about float charging at 13.2V because a car battery normally has 13.8V applied when running. My heater uses between 0.45 and 0.9A once the glowplug has gone out, depending on whether it is pulsing the pump or not. A 12A/hr battery should suffice if an intelligent charger is left connected. I am lucky enough to have `obtained` an eighteen Amp variable supply and a power out would only stop the heater briefly; it will just restart anyway as it would if the fuel ran out and was refilled (turn back on).

MH, I too was involved with those 4ft cubed x26 TX, open topped lead acids which would make your nose and eyes curl when entering the battery room. Not much elf``n safety in those days.

[Martin Harris - Moderator]

I remember being told that you couldn't claim for acid damaged clothing unless you could show corresponding holes in your "protective" clothing!

[Martin McIntosh]

Hmm, two piece boiler suit or a cow gown down to your ankles. Cannot recall anything else.

Way off subject, but we used to use the blue asbestos fire stopping sacks to play football with.

[Andy J]

Need to pass the standard 25mm flexi exhaust through a 28mm log wall cabin. Am I correct in assuming that a short length of 30mm OD steel pipe with a wall thickness of 1.5mm which the exhaust pipe will run through will be ok to give sufficient insulation to avoid any charring of the wooden wall.

[Martin Harris - Moderator]

I can't give you any informed opinion but I would monitor any arrangement you decide carefully. My exhaust pipe got hot enough to melt solder.

[Martin McIntosh]

Mine goes through hardboard, poly insulation and wood with no problems. It is a tight fit and no burning at all.

[Gary Manuel]

I was a bit concerned about running mine through my 75mm wooden log cabin wall. I wrapped some of THIS stuff around it and all has been well. It also fills any gaps between the hole and the exhaust to keep insects etc out.

[Barnstormer 52]

Andy

I have a similar log cabin.

I used some 40mm galvanised pipe from B&Q, only because that was all I could source easily. It is a fence post that is supposed to support a wire fence.

I wrapped the part of 24mm exhaust in the black heat wrap stuff in the reply above where it goes through the 40mm pipe, holding it in place by wrapping wire around it.

Make sure you put gloves on while you're handling the heat wrap stuff - its glass or carbon fibre.

The installation seems ok - although I keep an eye on it. I did think about 'borrowing' the meat thermometer from the kitchen to see how hot it gets, but it does get hot.

Occasionally when I get nervous about it I drip cold water on the 40mm pipe from a syringe - it seems to evaporate fairly quickly but doesn't sizzle.

As Martin H says you just need to keep an eye on it.

Geoff

[Martin McIntosh]

Might try that tape on a noisy two stroke petrol exhaust since the previously test Rescue Tape fell off before the models even got airborne.

Pic of my heater exhaust and no burning after two years.

[Gary Manuel]

Hi Martin / anyone else who might be interested.

The small hole that can be seen in the top of your silencer is intended to allow any oil or other fluids to drain out. It looks like your silencer is upside down. Not sure whether it'll make much / any difference but worth mentioning.

[Martin McIntosh]

Never noticed that, thanks. Trouble is that my support bracket would not fit if I turned it the other way up so it is a case of drill a hole at what is now the bottom or if it ain`t broke don`t fix it.

[Andy J]

Thanks all. Will go with a 30mm exit hole which then allows several wraps of the insulating exhaust tape and only if necessary purchase a short length of pipe.

On the topic of silencers, I purchased an original Eberspacher type and noted on that design that don't have a drain hole, so wondered how this was achieved on a standard installation.

[Martin McIntosh]

Got some of that tape but it is very thick and non adhesive so no good for a model exhaust. Wondered what would turn up from the description of 0.5cm/0.02" (!).

[Ronaldo]

Got my diesel heater up and running in my workshop, timed it nicely as its snowing and forecast to be cold over the coming week. I enclosed mine in a box as I make a lot of sawdust. The black on the sides is a home made air filter where the heater pulls the circulating air in, and made with DIY filter foam. Started up first time, and now been running on and off the last 4 days on kerosene with some diesel added to lubricate the pump as advised by some others who use them. Though I have read elsewhere on other forums that adding some diesel is not necessary, and some just use kerosene alone. At 65p a ltr  from a supplier just down the road from me it's certainly a big saving than using  diesel. The black 75mm ducting you can see on the outside wall is actually a cover I made to fit over the combustion air intake filter to keep it clean and dry.

All thats left to do is to box in the tank and pump on the outside wall with a hinged lid to keep the weather out. So far its all good, no probs. Thanks for all your informative posts on here, it was certainly useful .

 

[Gary Manuel]

Has anyone found out how to switch these into air conditioning mode? 

 

 

[Martin Harris - Moderator]

???

[Gary Manuel]

Well they are not much use in heater mode at the moment are they?

It was like an oven in my shed today.

[Andy J]

Love my heater but hate having to refill it as it is located against the shed wall and under the bench.  Hence getting a 5lt jerry can with a spout into the correct position is awkward to say the least.

Therefore wondering if one could position say an auxiliary 10lt tank on the outside wall of the shed such the the main tank in the heater is gravity fed via a flexible pipe when needed to be topped up using a bulkhead pipe adapter fitted to the main tank filler cap.  A simple on/off tap in the pipe would control the flow of additional fuel.  Will the concept work??

[Martin Harris - Moderator]

Sounds like a plan.  I use an electric submersible pump from a 2 gallon container but it has the potential to get messy.

[Dale Bradly]

I would disconnect the onboard tank, and extend the fuel line from the onboard fuel pump direct to the larger tank, wherever you locate that, be it inside or outside. Minimises chances of spills/overflows. A meter or two of extra fuel line won't be a problem. If you went further, like drawing from a very remote tank, move the fuel pump close to the tank. 

[Andy J]

Did wonder about getting rid of the onboard tank but again it is a major hassle to disconnect the exhaust and inlet air plumbing from the heater now that the bench is installed. Sure it would be a better concept to have a single tank mounted elsewhere, but monitoring fuel quantity status could be an issue particularly as I intend to put the header tank out of sight at the rear of the shed.

 

At least the way I intend to feed the current onboard tank is simple, only requiring a hole to be drilled in the existing fill cap to take a pipe bulkhead fitting.

 

Not sure if the existing tank is fully sealed or has an air bleed hole as inadvertently leaving the fill valve open would fill the tank to the brim potentially allowing diesel to escape over the heater which I assume would be dangerous. Open to suggestions how to avoid that scenario.

[Ron Gray]

The existing tank will have a vent in it, probably in the cap so that will need to be blocked off. As long as the existing tank is airtight then feeding it from, in effect, a header tank will be ok. However, I’m not too sure how leakproof the existing cap to tank seal is!

Edited December 15, 2021 by Ron Gray