Tumble dryers and spontaneous combustion.

[T i m]

Hi all,

The Mrs mentioned our old conventionally vented TD wasn't drying like it did so I first checked what power it was consuming with a plug-in power meter (thinking a heater element may have gone after all these years). Nope, ~250W running the drum and fan, ~1500W with the low temp setting and ~2400W on high. Except the heater was cutting out quite quickly maybe 10:1, off to on) so I wondered if the thermostat was getting weak ... or the airflow was obstructed somehow?

I then remembered I hadn't cleared the outside exhaust vent for quite a while and lo-and-behold, it was 50% blocked (doh).

That got me thinking of these dryers that are catching fire because of a buildup of lint on the element and how that can't be easy to overcome *if* it was a condenser dryer as I assume the same air was going round and round?

On our dryer, the air is drawn in from the outside of the cabinet via the heater element, though the drum, out via the filter, fan, exhaust pipes and wall vent, so very little chance of any lint getting near the heater element.

So, are the dryers that are catching fire typically the condenser type?

Cheers, T i m

[Michael Chare]

The vented Indesit tumble drier that I bought recently was one of the types that caught fire. In theory the design was modified before the product was despatched. I must remember to keep checking the filter.

[bert]

I suspect, but I'm only guessing that some accountant deep in the heart of Indesit decided to save two quid and removed the overheat cut out.

[T i m]

Ah ok thanks.

I don't suppose you know what caught fire on that particular model? Was it lint on the heater element (that seems most likely if it's allowed to happen by bad design, fault or poor (user) maintenance).

Are these 'filters' different on different machines (as I've only ever had this one TD)? On ours it's just some mesh on the inside of the door opening that you scoop / wipe off with your fingers after every load?

Cheers, T i m

[ss]

Going off topic a bit but I wonder if it would be as efficient to use a dehumidifier rather than a dryer. I have both but wife uses the dehumid more now than the dryer, I suppose it depends on the urgency of getting the clothes dry though. Just a thought.

[T i m]

We use a dehumidifier to dry some clothes that can't (or shouldn't) be tumble dried ... like daughters chainsaw trousers or some waterproof jackets.

Yes, that can play a big part, plus suitable space to turn into a drying room / area. For my Mrs a reason 'not' to use a dehumidifier is the need to hang all the clothes up to dry (rather than just poking them through a hole in a machine and pulling them out afterwards) and I'm not sure if dehumidified clothes also need ironing or come out as soft? (I know my flannel becomes rigid if the dehumidifier is left on in the utility room with the bathroom door left open).

And an interesting one, certainly re energy efficiency and assuming all things are equal.

Cheers, T i m

[Tim Watts]

My dehumidifier (compressor type) takes around 200-250W and about 4 hours of run time to dry clothes (they do have some extra air-drying time overnight without the dehumidifier running - so I'd say it has to be a lot more efficient.

There are dehumidifier based tumble dryers coming onto the market, I think Miele might do one.

[Tim Watts]

They are not as soft which is a downside. And things are more crinkly.

[Tim+]

I wonder how they compare with a gas tumble dryer though?

Tim

[T i m]

It can be if not a jacket etc.

Ok, not an issue in some cases (jackets / PPE) but as I can't remember the last time any of us got the iron out ... ;-)

Cheers, T i m

[Nick]

In message , T i m writes

Another one bites the dust...

Mine's a Hotpoint, vented, with a filter that slides up out of the bottom of the door frame. I got an email yesterday saying they expect to repair it in November. Their sense of urgency is quite impressive :).

[T i m]

So, are these TD's designed is such a way that any lint that gets past the filter can get onto the heater element?

As I said, I believe on mine it's: Air intake at the back of the cabinet > heater > drum > filter > fan > exhaust.

I think if I had a TD that was on the hit list I'd be tempted to just replace it (you could always sell if after it got updated) but how would you know that the new one wouldn't appear on the list in the future? ;-(

Cheers, T i m

[Michael Chare]

You can look at the filters on the different machines in Currys. On ours, the filter is just inside the door. You lift it out to clean. The problem was caused in part by people not cleaning the filters. Clearly if the filter gets blocked there is no airflow and the whole machine will get to hot, especially near the heating element.

I am aware that the filter on the previous machine we had did not get cleaned that often! The replacement machine has sensor drying.

[F]

Hotpoint will replace it with a vented model for £59 or a condensing model for £99. They install the replacement and take the old one away. They are currently replacing on dates at the end of this month.

[tabbypurr]

200w 50% of the time for 1hr plus 40w for a big fan = 140WH. Versus TD at 2kW taking, I don't know 20 or 30 mins = 660 to 1000 WH.

Most things are dry in an hour if you add a fan.

the wardrobe

most clothes need to be hung up anyway, so no extra step.

The only thing I find comes out any stiffer is towels, but only very mildly. It's not an issue IRL.

Tim Watts:

If you add a fan that drops dramatically.

NT

[T i m]

Sounds like a fun day out. ;-)

That sounds like the filter design in both of our dehumidifiers.

Another 'problem' with that design might be (especially if the filter is flat) it's not too difficult to knock some lint off the filter and into the machine whilst cleaning it?

Ours stays put so there is *no* chance of any lint getting past it (if already caught by it etc) and because it's visible every time you open the door *very easy* to clear every use. In fact, because there is a chance that you will pull the lint out as you pull the clothes out you automatically clean the filter before you do.

I wonder if things were just designed better in those days as I have often heard people say things like 'they don't make things like they used to' and 'I wish this new was as easy to use as our old one'.

Ours is supposed to have that but I'm not sure how accurate it is.

Cheers, T i m

[T i m]

Same here and we generally buy clothes with that in mind.

Many of mine's do also but far from all (now days).

Cheers, T i m