Small Chinese Diesel Heaters

[worn thumbs]

I spent a few years working in a building with air source heat pumps and the working temperature was always good.Maybe the Chinese will come up with a low cost version,you have to think that it could do a bit to relieve global warming.In the short term the low cost oil heaters have to be worth a look,they are light years ahead of the paraffin space heaters I remember as the combustion products are ducted outside.

 

[beech1948]

Siggy,

This will probably be my last post for a week or so as I have a job to complete.

Fuel consumption figures have been from a couple of Youtube videos. The range of fuel use on Low is claimed to be 144ml/hr with high burn rate being 382 ml/hr. A third fuel test video shows a use rate of 10 litre per 25.5 hr period when on High burn. So quite a range of measurements available.

A diesel heater will be cheaper than my propane gas. However, the savings may be lower than hoped for.

I have just realised that I could also try to run this on vegetable oil which would be cheaper than diesel. Or a mix of diesel and veg. oil. A bit of a PITA though with all the mixing.

I will be back in touch in a week or so.

 

[beech1948]

Rorscharch,

I intend to find out which is the cheapest approach. I am also a pretty logical chap who hates the " I think it will be dearer " emotional response. It may well end up more expensive but I need to seek out the reality of the numbers.

My workshop is quite well insulated with 4" in the roof and walls and just under 2" foam between my concrete base and the wooden floor. Doors are draft proofed. Windows are double glazed. Only cold spots are where services enter the building. Foaming these was less successful but the heat loss due to the services is minimal.

 

[siggy_7]

I would trust basic maths a lot more than a YouTube video. The calorific value of 28 second heating oil (aka Kerosene) is about 10.35kWh per litre; diesel is closer to ~10.8kWh/litre I think. So running at 100% efficiency and rated output, a 5kW heater will burn about 450-500ml/hr of fuel. These aren't too far off the figures you are quoting, so given that these heaters are definitely not 100% efficient (my guess being more like 70%) they aren't running at rated output - assuming they are 5kW heaters. One potential traps to be aware of is that these are sold with badged outputs of 2kW, 5kW and 8kW but externally they all look comparable - so be sure you are comparing like with like. Also some people adjust the fuel pump speed in attempts to tune the unit for whatever reason - increasing output/efficiency/burn cleanliness etc. - which obviously makes their consumption figures less relevant to your use case unless you copy the settings.

As I said, if you work on a 70% efficiency and the calorific value of your fuel I reckon you'll not be too far wrong with fuel consumption figures. You then have a fuel consumption per kWh of heat, which you can compare to your propane fired unit and then cost it out. Propane costs what, £55 for a 47kg cylinder these days? With a calorific value of ~13.7kWh/kg, that works out at about 8.5p/kWh of heat before factoring for whatever the thermal efficiency of your heater is. That's the comparison that is relevant for you I think.

I would be very suprised if you could run one of these units on plain vegetable oil - it's far too thick and the vapourisation temperature will be too high. If you have a cheap supply of vegetable oil you could try making your own biodiesel, but that's quite an involved process. Sourcing red diesel or kerosene is likely to be more cost effective and less hassle.

Sorry if I'm coming across as negative, as I said I like my unit and it's a good solution but it hinges on having affordable fuel. My main advice to you is to be realistic with fuel consumption figures and have a fuel source worked out before you commit to the purchase.

If you want to know more about the Chinese diesel heaters specifically, there is a popular Facebook group you can join which has a lot of active contributors and a few useful technical documents too. The group is "Chinese Diesel vehicle air heaters - Troubleshooting & Parts sales."

 

[user22161]

Not helpful as you are making a number of erroneous assumptions.
1) Heater is a sealed unit
2) Heater has an external exhaust
3) Intake air and outtake air are separate from the exhaust
4) Can be arranged to have air in/out from shop and exhaust and diesel feed to be from outside

Doubt that this would suffocate me.

I've had Eberspacher diesel heaters on boats (including the one I'm sitting in now) for 25+ years and had no problems whatsoever. Ebers and Webasto are taking a hammering recently as the Russian Planar heaters are about half the price with full UK service and parts - https://planarheaters.co.uk/ - and now the Chinese clones at ridiculously cheap prices but there are varying reports about reliability and spares availability with those.

 

[gmgmgm]

My garage is double skin concrete block with an insulated cavity, bare concrete floor and no roof insulation. The heater on full blast raises the temperature at about 2C/hr (it's a lot of thermal mass!). Once up to temperature, the heater sits on low for I would guess 80% of the time.

The best way of thinking about it is in terms of cost per kWh of heat. At a guess of 5kW of useful heat output and 0.7l/h of fuel, at 50p/l (I have oil fired heating so ready supply of heating oil) it's costing me about 7p/kWh of heat. Using electricity would be about double that, so for me it's cost effective. If you had to run it on fuel with road duty I reckon it's comparable or maybe more expensive than electric, so not worth it. In that situation, I would look at air source heat pumps.

Great analysis. At 7p/kwh you can work out how many kwh needed to pay back the capital costs (at kerosene prices; taxed diesel will be rather higher!)

I have an Eberspacher in our campervan and it's very good technology. As said elsewhere, there are now cheaper versions coming online. I think it comes down to a choice between diesel/kerosene heaters, electric heaters, air-source heat pump or wood burner.

If you have a clean and insulated workshop, then air source (air-to-air) makes a lot of sense, as they give you climate control, automation (wifi) and air-con in the summer. Cheap ones are about £1k. Plumber usually needed to connect the refrigerant pipes.

I ended up going with a wood burner as I have "free" logs. The side benefit is that my workshop is now super tidy and there are no small offcuts lingering in corners. Everything feeds the fire!

 

[beech1948]

My garage is double skin concrete block with an insulated cavity, bare concrete floor and no roof insulation. The heater on full blast raises the temperature at about 2C/hr (it's a lot of thermal mass!). Once up to temperature, the heater sits on low for I would guess 80% of the time.

The best way of thinking about it is in terms of cost per kWh of heat. At a guess of 5kW of useful heat output and 0.7l/h of fuel, at 50p/l (I have oil fired heating so ready supply of heating oil) it's costing me about 7p/kWh of heat. Using electricity would be about double that, so for me it's cost effective. If you had to run it on fuel with road duty I reckon it's comparable or maybe more expensive than electric, so not worth it. In that situation, I would look at air source heat pumps.

Great analysis. At 7p/kwh you can work out how many kwh needed to pay back the capital costs (at kerosene prices; taxed diesel will be rather higher!)

I have an Eberspacher in our campervan and it's very good technology. As said elsewhere, there are now cheaper versions coming online. I think it comes down to a choice between diesel/kerosene heaters, electric heaters, air-source heat pump or wood burner.

If you have a clean and insulated workshop, then air source (air-to-air) makes a lot of sense, as they give you climate control, automation (wifi) and air-con in the summer. Cheap ones are about £1k. Plumber usually needed to connect the refrigerant pipes.

I ended up going with a wood burner as I have "free" logs. The side benefit is that my workshop is now super tidy and there are no small offcuts lingering in corners. Everything feeds the fire![/quote.

Gmgmgmgm,
Did you find that your insurance company increased premiums for the wood stove.

Al

 

[gmgmgm]

Gmgmgmgm,
Did you find that your insurance company increased premiums for the wood stove.
Al

Hmm- this is a small outbuilding for home working (and installed to required standards) so I haven't specifically informed the insurance company. Should I? We already have log fires/burners in the house.

For a professional workshop it's probably more of a concern.

 

[beech1948]

Well folks the numbers are crunched, the verdict is in.

I reduced all of the calcs to KWh depending on the calorific value of the fuel. This shows that the following hold true in my case and situation.

1) Propane bulk tank ---£1845 per 12 months ( Xmas to Xmas)
2) Diesel heaters x2 ( Chinese and German) ---£1440
3) Diesel/Veg oil mix -- too much trouble to filter and mix
4) Standard wood stove --- £600 --- with issues of extra insurance/lighting in am/ash etc
5) Gaseous wood stove or Rocket stove --- £600
6) Electricity ....£2200 estimated

Solution is to return to a wood stove of some sort as the cheapest option between bought in wood and my off cuts. Issues are really about convenience as I would need to extinguish at night, relight in the morning, feed during the day so some additional inconvenience compared to propane. There is also the acquiring, receiving, stacking, covering and carrying of wood to the fire. Might even need to build a deck + canopy to hold wood stocks by the door. Maybe a time to reflect/think/divert myself from the drudgery of making a living.

I am for some reason still reluctant to go back to wood as a fuel.

 

[Phil Pascoe]

Why would you need to extinguish the stove at night? They're enclosed and perfectly safe. Another bonus of course is that your workshop waste, cardboard etc. goes into it.

 

[AndyT]

What an interesting thread this is. Here's a real decision, being thought about in detail by someone who wants to get it right, and the answer is by no means clear or obvious.

(Even less so if you try to predict how the prices of each option will change in the next ten years, or model the capital cost of future replacement kit after its expected lifespan.)

But worldwide, the total effect of millions of little decisions like this matters, for our own wellbeing and that of future generations. Sometimes, some governments try to persuade us to favour one energy source over another, but there is often mistrust of what are dismissed as 'green taxes' or the effect of vested interests.

I'm sorry this is no help in making your decision, but you just caught me at a thoughtful moment!

 

[gmgmgm]

6) Electricity ....£2200 estimated

Is that for "vanilla" electricity, or heat pumps? In theory you should get a CoP multiplier of 3x for air-to-air heat pumps, so saving two-thirds of the running costs.

How about wood + air-to-air? That gives you wifi/remote control of warming up the space, a disposal system for all offcuts, and a backup heater if you're out of wood/ don't have time.

 

[beech1948]

What I am beginning to find is that insurance companies do not like a lit unattended fire in a building which has a commercial purpose. My insurance co's immediate reply was to decline any further insurance if I moved to a wood burner which would be unattended at night time. They still have not decided to accept my ideas for change to heating source. The battle goes on.

 

[beech1948]

6) Electricity ....£2200 estimated

Is that for "vanilla" electricity, or heat pumps? In theory you should get a CoP multiplier of 3x for air-to-air heat pumps, so saving two-thirds of the running costs.

How about wood + air-to-air? That gives you wifi/remote control of warming up the space, a disposal system for all offcuts, and a backup heater if you're out of wood/ don't have time.

Yes that was for "vanilla with cherries on top" electricity.

You raise a sort of good point. There are a few alternatives to wood as heat sources.

a) air-to-air heat source......doesn't work well at low temps so for maybe 2 months or so a year that would need a secondary heat source.
b) wood + air-to-air.....I have not investigated but the fear is that the overall costs would be too much.
c) Waste engine oil injected into a modified wood burner stove. I just heard about that today. So no thoughts yet.
d) Ground source heat pump. Drill a holes or is it holes and pump ,water through it to a depth of 100ft +++ and extract the heat. Probably costly.
e) Solar hot water...likely too costly
f) Solar battery driven via electric heater...not even certain it would be possible.

All these thoughts come with various investments in equipment at a variety of cost levels. It is not just the cost of heating. For example a friend has had a quote of £11,900 for an in ground heat pump. That would be too much for me to bear.

My motivation is to reduce my costs not increase them.

 

[gmgmgm]

6) Electricity ....£2200 estimated

Is that for "vanilla" electricity, or heat pumps? In theory you should get a CoP multiplier of 3x for air-to-air heat pumps, so saving two-thirds of the running costs.

How about wood + air-to-air? That gives you wifi/remote control of warming up the space, a disposal system for all offcuts, and a backup heater if you're out of wood/ don't have time.

Yes that was for "vanilla with cherries on top" electricity.

You raise a sort of good point. There are a few alternatives to wood as heat sources.

a) air-to-air heat source......doesn't work well at low temps so for maybe 2 months or so a year that would need a secondary heat source.
b) wood + air-to-air.....I have not investigated but the fear is that the overall costs would be too much.
c) Waste engine oil injected into a modified wood burner stove. I just heard about that today. So no thoughts yet.
d) Ground source heat pump. Drill a holes or is it holes and pump ,water through it to a depth of 100ft +++ and extract the heat. Probably costly.
e) Solar hot water...likely too costly
f) Solar battery driven via electric heater...not even certain it would be possible.

All these thoughts come with various investments in equipment at a variety of cost levels. It is not just the cost of heating. For example a friend has had a quote of £11,900 for an in ground heat pump. That would be too much for me to bear.

My motivation is to reduce my costs not increase them.

d+e+f: We have GSHP which heats the house. It will cost you a fortune to install. Solar (thermal or PV) will also cost a lot to install. Don't even think about batteries!

Air-to-air heat pumps can sometimes be DIY fitted for £1k, and in the worst case (moist snow-storm) they won't be any worse than a vanilla electric heater.

We're getting in to "analysis paralysis" here... but putting in a wood burner (ignoring insurance/commercial concerns) is pretty cheap (capital and op cost), whether you augment that with vanilla electric or something more sophisticated.

 

[Rorschach]

How cold does it (regularly) get where you live? A quick google suggests air source heat pumps can work down to as low as -15c or lower. Do you regularly get temps that low?

Remember you don't want to plan for worst day of a winter, you want to plan for the average day or a winter.

Where I live we have temps down to -5c for maybe 1-2 days every couple of years. Average winter temps are in the 5-10c area.
It would foolish of me to discount an air source heat pump on the basis that every couple of years it will struggle for a few days. The reality is it would work superbly for 99% of the time I needed it and very occasionally it would struggle and I might need a backup electric heater.

 

[Just4Fun]

d+e+f: We have GSHP which heats the house. It will cost you a fortune to install. Solar (thermal or PV) will also cost a lot to install. Don't even think about batteries!

I don't know what your experience with GSHP has been like, but in our case the initial installation cost was only the start. It is a rare winter when we don't have some sort of problem with it needing a lot of fettling by me and/or attention from the company who originally installed it. In theory it is cheap to run but in reality the service/maintenance costs eat into the savings and add to the hassle factor.

I don't have any experience with solar PV but our solar thermal system has easily paid for itself. It produces about 7,000 kWhr per year from 80 evacuated tubes, which mainly supplements the central heating. It is easy enough to DIY install which brings the cost down. Over the course of a year it is a benefit but there are long periods when it does nothing so can only ever be a bonus, never a main heat source.

 

[Phil Pascoe]

From what a plumber told me recently the solar thermal systems have changed - they are not a straightforward water based system any more, and it's debatable whether they can ever cover their cost. My friend installed his own in in the early '80s and swore by it.

 

[Rorschach]

I'd be interested to compare Solar Thermal to Solar PV connected to an immersion heater.

I would guess the Solar thermal is more efficient but to me the PV would be a better option. Prices are coming down, and the energy produced is more versatile since you can use it for hot water or other electrical needs.

 

[worn thumbs]

There has been a long running thread on these heaters on a boating forum http://www.ybw.com/forums/showthread.ph ... 9fbb93df73 .In essence you could buy a dozen or so for the cost of one of the established brands.

They are a much better idea that a paraffin burner in the workshop or one of the diesel or bottled gas space heaters.I do understand the concerns about insurance,but I would have thought much the same applies to any domestic oil fired heating.

A very long time ago I worked in a building that had a cast iron woodburner in the corner and it was a good way to get rid of mistakes,sapwood and offcuts.It got less good as a source of heat the further you happened to be working from it.