Ultraheat Pro: Snake oil highly efficient heater....

[james_s]

Any electric heater is 100% efficient which says it all. You cannot go above that unless it's a heat pump which of course requires indoor and outdoor units connected together with tubes.

Every electric heater is 100% efficient at turning electricity into heat, although some are better than others at putting the heat where you want it which could arguably be considered as part of the total efficiency. A radiant heater for example will be much better at heating a person sitting near it, while a forced air heater with a powerful fan that blows heated air where you want it is better at warming the entire room. A forced air heater with an inadequate fan will create a bubble of heated air around the heater itself which will take a while to spread through the room. There is really no magic to it though and most of the heaters sold as being revolutionary in one way or another are really nothing special.

[Fraser]

I just tested my Dragon 4 on its 900W setting and thermal equilibrium at the top of the oil chamber  occurred at 100.3C

On the 1100W setting the temperature on the top of the oil chamber rose to 115.3C and this looked close to thermal equilibrium.

Fraser

[wraper]

So I tested my MILL AB-H1500DN heater which is rated for 1.5 kW. Right away it consumed 1560W, checked after 8 minutes at full power - 970W. At 30 minutes still 970W. Interestingly when changed power settings at hot state, low setting resulted in zero consumption, mid and high settings were the same 970W. So not nearly as bad as those cheap heaters but still cheating and should be rated as 1000W instead.

[Fraser]

Wraper,

I have to wonder whether the exterior temperature of those oil heaters is being deliberately limited for safety ? The Dragon 4 gets really hot on its 2000W setting. The following temperatures on the top of the oil chamber were measured at the three power settings…….

900W   = 100C
1100W = 115C
2000W = 178C

Fraser

[wraper]

Wraper,

I have to wonder whether the exterior temperature of those oil heaters is being deliberately limited for safety ? The Dragon 4 gets really hot on its 2000W setting. The following temperatures on the top of the oil chamber were measured at the three power settings…….

900W   = 100C
1100W = 115C
2000W = 178C

Fraser

Dunno but you can only heat it to a certain point before oil starts boiling. Googling shows temperatures about 280^oC when high temperature mineral oils start boiling. So you cannot get much above that anyway. Uncovered heaters are also more dangerous to cause burns so it may be a reason for more aggressive power reduction too. FWIW larger power rating sells a cheaper to make model for more money, buyer will likely to chose more compact one too.

[wraper]

https://www.multitherm.com/multitherm-pg-1.html this particular oil has: Maximum Recommended Operating Temperature 600°F / 316°C

[james_s]

Wraper,

I have to wonder whether the exterior temperature of those oil heaters is being deliberately limited for safety ? The Dragon 4 gets really hot on its 2000W setting. The following temperatures on the top of the oil chamber were measured at the three power settings…….

900W   = 100C
1100W = 115C
2000W = 178C

Fraser

Dunno but you can only heat it to a certain point before oil starts boiling. Googling shows temperatures about 280^oC when high temperature mineral oils start boiling. So you cannot get much above that anyway. Uncovered heaters are also more dangerous to cause burns so it may be a reason for more aggressive power reduction too. FWIW larger power rating sells a cheaper to make model for more money, buyer will likely to chose more compact one too.

Put it in a cold room and maybe it will continue drawing the full power. A heater really needs to be rated at the maximum power it can draw rather than the average power.

[wraper]

Put it in a cold room and maybe it will continue drawing the full power. A heater really needs to be rated at the maximum power it can draw rather than the average power.

As it took only a few minutes to drop the power, really doubt that will help. Room temperature was about 18^oC. Yes it needs to be rated for maximum power, however this maximum power is mostly a gimmick which allows insignificantly faster initial heating and no sustained power rating was given.

[Fraser]

Wraper,

This is a really interesting discovery regarding these oil filled heaters. Thank you for highlighting the situation with some models, even quite expensive ones.

Fraser

[james_s]

It might help more than you think. In a cold room the oil will be cold, and a lot more heat will be drawn from the oil, it's hard to say without trying it though.

[Fraser]

The fan heater that the OP highlighted has been reviewed by Krazy Ken 

Look here….

https://youtu.be/ot1JsRyjLcg

Quoting Krazy Ken’s opinion of the unit …. “An over priced piece of junk…. Do not buy it”

Fraser

[Someone]

I have to wonder whether the exterior temperature of those oil heaters is being deliberately limited for safety ? The Dragon 4 gets really hot on its 2000W setting. The following temperatures on the top of the oil chamber were measured at the three power settings…….

900W   = 100C
1100W = 115C
2000W = 178C

100% this! while the old "bar" resistive heaters would be dangerous to touch, that sort of questionable consumer safety is a thing of the past. Non-industrial heaters need to be safe to touch in operation to meet current product safety requirements, so oil heaters with accessible metal fins will be running a thermostat on that bulk.

[NiHaoMike]

For room heating it is actually better to use a convection heater, with special mention for oil filled convection heaters. They create the same thermal energy as their equivalent fan heaters but they create a far nicer warming effect as the oil continues to emit heat whilst the thermostat is off, and this is nicer than the hot on/off effect of a fan heater. With oil filled heaters you do need to switch them on earlier than a fan heater to gain the best effect however.

Wouldn't triac control work the best, no cycling and fast response?

[Someone]

For room heating it is actually better to use a convection heater, with special mention for oil filled convection heaters. They create the same thermal energy as their equivalent fan heaters but they create a far nicer warming effect as the oil continues to emit heat whilst the thermostat is off, and this is nicer than the hot on/off effect of a fan heater. With oil filled heaters you do need to switch them on earlier than a fan heater to gain the best effect however.

Wouldn't triac control work the best, no cycling and fast response?

cost optimized consumer products tend not to have intelligent control schemes, bi-metal electrical thermostats are just that cheap.

[AVGresponding]

These things (the good quality ones like your DeLonghi units at least) will be filled with mineral oil, which is odourless.

There are a lot of mineral oils and most of them have a strong odor. And even types which are completely odorless become smelly after years pass. Considering oil gets very hot in the radiator, I would assume even odorless oil will somewhat decompose and become smelly. Not to say I really doubt radiators are usually filled with more expensive odorless oil rather than some cheaper stuff as radiators are sealed anyway. If there is some smell, it means either there is a problem with sealing or some oil contamination was left outside if radiator during manufacturing which starts to smell when heated up.
Here is a video where a guy takes it apart. At 4:45 he says it smells like an automotive garage.

I was referring to so-called "white" or "light" mineral oil, which is odourless, and far from expensive. These radiators shouldn't get anywhere near the boiling point of the oil, but there are probably pockets of trapped air?   

In terms of the degradation over time, oil does not "decompose" as you put it. I mean, it's been decomposing organic matter at one point, but that was millions of years ago... The aromatics are the fractions that boil off first, so this becomes less smelly over time. It's not going to degrade in the way the oil in an ICE engine does, as there will be no combustion by-products contaminating it, and much lower temperatures.
I suspect the stuff in radiators that does smell is either a different grade, maybe for cost or thermal characteristics, or maybe someone just refilled it with engine oil. No idea.

If you want your radiator to smell better, just drain it and refill with baby oil, which is just a perfumed mineral oil!   

[wraper]

In terms of the degradation over time, oil does not "decompose" as you put it. I mean, it's been decomposing organic matter at one point, but that was millions of years ago...

Really? Have you never seen petroleum products degrade over time? For example I have a small bottle of Panasonic mineral oil for razor lubrication which is no longer useable for the purpose. It was odorless initially but after a decade it smells like a usual multi-tool oil. But gasoline usually has a shelf life of three to six months.

The aromatics are the fractions that boil off first, so this becomes less smelly over time.

There is nowhere for them to go away so it cannot become less smelly because something evaporated.

It's not going to degrade in the way the oil in an ICE engine does, as there will be no combustion by-products contaminating it, and much lower temperatures.

Let's see what manufacturer of high quality oil says

https://www.multitherm.com/multitherm-pg-1.html

Long Term Temperature Control
All organic heat transfer fluids undergo thermal degradation over time. Conventional synthetic fluids or low quality oils will form soft carbon material (sludge) that eventually coats all system surfaces, and can form a hard coating. Because the coating acts as an insulator, heat transfer rates are reduced resulting in longer heat up time, lower production rates, changes in control response and, in extreme cases, burnout of heater tubes or electrical elements.

With non-fouling MultiTherm PG-1®, these problems disappear. As it degrades, it produces small carbon particles that do not stick to system surfaces, but remain suspended and are easily drained or filtered out. Since heat transfer surfaces remain clean, system performance remains constant.

If you want your radiator to smell better, just drain it and refill with baby oil, which is just a perfumed mineral oil!

And have an explosion (due to boiling) in the middle of your room with hot oil splattering around and possibly self-igniting, hopefully you won't be there when it happens.

[AVGresponding]

Your "degradation" example isn't very useful. We have no idea what the bottle is made out of; it's quite likely the oil is a mild solvent for the polymer of the bottle and has become contaminated.

If there's no way for the aromatics to vent, there's no way they can be smelled.

Quoting the sales blurb from a manufacturer that has a vested interest in selling you a product is a long way from an actual scientific study.
If you want to debunk my claims/opinions, that's fine, I don't mind being proved wrong. Sales spiel isn't proof though.

Although my comment about baby oil was facetious (which I'm sure you realised but chose to ignore) there's no reason to suppose it would be an explosion risk. Since the product is intended for use on the delicate skin of a baby, it does not contain volatile aromatics, as these would be a skin irritant. They make the stuff as inert as possible.

[wraper]

Quoting the sales blurb from a manufacturer that has a vested interest in selling you a product is a long way from an actual scientific study.
If you want to debunk my claims/opinions, that's fine, I don't mind being proved wrong. Sales spiel isn't proof though.

Marketing says their oil decomposes too, must be an utter lie .

Although my comment about baby oil was facetious (which I'm sure you realised but chose to ignore) there's no reason to suppose it would be an explosion risk. Since the product is intended for use on the delicate skin of a baby, it does not contain volatile aromatics, as these would be a skin irritant. They make the stuff as inert as possible.

My comment was not about it being inert or not but about its components boiling off and creating high pressure at lower temperature than specialized high temperature oil. Also I see these oils usually contain a few % of perfumes.

[AVGresponding]

It certainly isn't a scientific study, and the word "decompose" has a specific and different meaning to that of "degrade".

[wraper]

It certainly isn't a scientific study, and the word "decompose" has a specific and different meaning to that of "degrade".

Google says:

decompose: (with reference to a chemical compound) break down or cause to break down into component elements or simpler constituents.

What manufacturer says is exactly that:

With non-fouling MultiTherm PG-1®, these problems disappear. As it degrades, it produces small carbon particles that do not stick to system surfaces, but remain suspended and are easily drained or filtered out.

[wraper]

Your "degradation" example isn't very useful. We have no idea what the bottle is made out of; it's quite likely the oil is a mild solvent for the polymer of the bottle and has become contaminated.

Bottle is made of polypropylene, good luck dissolving that. And neither it should smell if dissolved.

[AVGresponding]

Solvent resistant is not the same as solvent-proof. As it happens I use something in my day job that dissolves pp; it's called solvent weld, I use it for plastic conduit that I'm running cables through, plumbers also use it.

Mineral oil contains a mix of alkanes and will dissolve pp, just very slowly.

You are probably correct that this does not cause the odour though, the effect would be too small and too slow.

The most likely explanation AFAIK is degradation (not decomposition) of the oil by oxidation which causes polymerisation (the opposite of decomposition if you think about it) and the evaporation of the lighter fractions.

My knowledge of organic chemistry isn't good enough to expand on that though, and I'm at work and using my phone to reply, so not in a position to go on an extended gurgle safari.

[wraper]

Solvent resistant is not the same as solvent-proof. As it happens I use something in my day job that dissolves pp; it's called solvent weld, I use it for plastic conduit that I'm running cables through, plumbers also use it.

And I call it BS, PP is nothing like ABS or PVC.

[AVGresponding]

Solvent resistant is not the same as solvent-proof. As it happens I use something in my day job that dissolves pp; it's called solvent weld, I use it for plastic conduit that I'm running cables through, plumbers also use it.

And I call it BS, PP is nothing like ABS or PVC.

My bad, I mis-spoke. No need to be aggressive about it though.

[Helio_Centra]

Big Clive just did a tear down and review of this heater.



Spoiler: it is just a completely average 500W heater. And considering that most all department store heaters in countries on 120V will be 1500W and in countries with 220-240V will be 2000W it will kinda be terrible unless it is just heating a small room.