Use a dehumidifier or heater to dry clothes?

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I find that in Winter,once there is frost the humidity is too low inside with the heating on, and I end up having to use a humidifier to avoid dry eyes and sore throats!

Qyburn

wittynamegoeshere said:

I'm pretty sure my dryer's nothing like 70p for a full load, more like half that, and it takes an unbelievable amount.

That sounds like you have heat pump dryer. Do you know how much power does yours take while it's running?
Condenser or vented dryers are going take something like 2.0-2.5kW.
  

m_c_s

Condensing tumble dryers also have heat pumps in them ... the more energy efficient ones.

Typically they use between 175 and 225 kWh per annum so extremely efficient.
In terms of single loads ours use 1.6 kWh for a full 7kg load of cottons to fully cupboard dry and that takes over 2hrs. So 1.6 x 34.226p = 68p. 
Half load of 3.5kg uses only 0.5kWh so 17p.
The Bosch condensing heat pump tumble dryer we have recommends in its manual that clothes are spun at 1400rpm in the washing machine to maximise efficiency. Typically cotton clothes spun at 1400rpm come out with 50% moisture, while at 1000rpm there is 60% and at 800rpm there is 70% moisture still left in the clothes. Easy care fabrics have a lower moisture content but still 40% moisture content after the 800rpm spin.

_Jem_

rothesy said:

Think about the damage to your property and your health as well.  This should come first over the cost of running.

This is absolutely true, my first place was just terrible very cold no double glazing, and a massive problem with mould, it got so bad my daughter ended up in hospital with pneumonia. dehumidifiers were expensive back then. The Landlord didn't care. 

Jibber123

A dehumidifier will not stop mould growth on its own. Mould forms if the conditions are right, warm and damp and a food source i.e. dirt. The condensation or water appears on the walls and windows as their surface temperature is below that of the air, and the air is already heavily saturated with water. When the moist air touches the cold surface its temperature drops and as a result it can hold less water vapour, the excess water appears as droplets on the surface. This then accelerates the mould growth in ideal conditions. We brought a Meaco 20l dehumidifier about 5 years ago as we had similar problems, it did help in the winter months as it reduces the amount of water vapour in the air, we were emptying it about every 24 hrs especially if it was wet outside. However we've found the biggest culprits were cooking and showers. Unless you've got a very good extractor system capable of removing the wet air at source this will be a major cause of increased damp, together with drying washing indoors. Always try and dry cloths outside it removes the problem at source. Again try and prevent as much wetness from coming into the house in the 1st place, it is very difficult in a English winter as we get days of cool damp weather. We put up a lean-to by the back door which catches the sun, we use it to dry off wet jackets boots and washing if its raining, the dogs also get left out there after a walk to dry off a bit before coming in the house. Unfortunately the only other solution is to try and raise the surface temperature where the mould is forming, normally cold North East corners and behind furniture where there is little air movement. Putting the heating on raises the air and surface temperatures allowing the air to hold more water vapour in suspension. Fitting insulation will also help to prevent cold spots on the walls, however be warned in older properties that weren't designed to have insulation fitted this can sometimes cause more problems as the damp will get trapped under the insulation (Interstitial condensation). Don't forget we also breath out  about 1/2 pint of water vapour while we sleep as well. A dehumidifier will only help to remove some of this water its a lot easier to catch it at source before it gets into the air

wittynamegoeshere

Spoonie_Turtle said:

wittynamegoeshere said:

They're pretty affordable though, not the sort of money involved in getting an electric car or heat pump heating system.  You get a return on that investment, plus I'd put a fair bit of value on not having a home full of wet washing, especially in a home that's already known to be damp anyway.

Affordability is relative.  Multiple hundreds of pounds puts them in the 'considered purchase to be saved up for' category for a lot of people, similar to any new energy efficient appliances like that.  Return on investment is great but relies one being able to invest in the first place.  Which, granted, the OP may be able to, it was just your generalised statement that I disagreed with.

I get the impression that you're trying very hard to find things that you can misinterpret as in some way offensive for some reason.  Should we avoid suggesting anything that costs money now, just in case someone who can't afford it reads it?

My original statement was that they're not a luxury, meaning that those who have them would be best off to use them.  Sadly a lot of people still think they're only slightly less expensive to use than the old tumble tryers(!), in reality they cost a fraction of the price.  So those who have one should just chuck everything in and not have any planet-killing guilt, they probably cost less to run than the cost of the extra heating needed if you dangle cold wet fabric all over the house on its own, never mind the additional cost of running a dehumidifier and any indirect costs such as damage to the building and health.

The origin of my statement was that my OH's parents had a washer-dryer once, they used it lots then got a massive leccy bill.  They thought I was nuts when I told them we tumble dry everything, they just "know" that tumble dryers are expensive to run and are only for emergencies.  I suspect a lot have this same attitude, and probably some have a heat pump tumble dryer sitting there doing nothing while they dangle wet washing all over the place, probably costing them more as well as causing harm...

https://www.bbc.co.uk/news/uk-63642856

Exposure to mould in the home can be damaging to your health.

An inquest found that two-year-old Awaab Ishak died as a result of a severe respiratory condition caused by prolonged exposure to mould in his home in Rochdale.

[Deleted User]

wittynamegoeshere said:

The origin of my statement was that my OH's parents had a washer-dryer once, they used it lots then got a massive leccy bill.  They thought I was nuts when I told them we tumble dry everything, they just "know" that tumble dryers are expensive to run and are only for emergencies.  I suspect a lot have this same attitude, and probably some have a heat pump tumble dryer sitting there doing nothing while they dangle wet washing all over the place, probably costing them more as well as causing harm...

I'm probably in that same position.  Have an old vented dryer in the garage, but it's expensive to run so use it about twice a year.

Never even considered a new one because I "know" that it would be just as expensive.  Reading here has made me re-consider, I keep my heating down quite low (16.5C) so things stay damp for a long time and that can't be good.

Heat pump tumble dryer seems like it's the best solution for drying clothes, but would a dehumidifier be more useful overall?

Also, is there any problem with using either appliance in an unheated space like a garage?

k_man

[Deleted User] said:

wittynamegoeshere said:

The origin of my statement was that my OH's parents had a washer-dryer once, they used it lots then got a massive leccy bill.  They thought I was nuts when I told them we tumble dry everything, they just "know" that tumble dryers are expensive to run and are only for emergencies.  I suspect a lot have this same attitude, and probably some have a heat pump tumble dryer sitting there doing nothing while they dangle wet washing all over the place, probably costing them more as well as causing harm...

I'm probably in that same position.  Have an old vented dryer in the garage, but it's expensive to run so use it about twice a year.

Never even considered a new one because I "know" that it would be just as expensive.  Reading here has made me re-consider, I keep my heating down quite low (16.5C) so things stay damp for a long time and that can't be good.

Heat pump tumble dryer seems like it's the best solution for drying clothes, but would a dehumidifier be more useful overall?

Also, is there any problem with using either appliance in an unheated space like a garage?

For a dehumidifier, would you still use that in an unheated space like the garage?

Dehumidifiers need heat to dry the air.
Compressor based ones just get less and less efficient as the temp drops, and don't dry much below about 15C. They do generate a bit of heat, but not much.
Desiccant ones generate heat as part of the process, but this heat is then likely to be wasted if in a garage etc.
Also efficiency in a garage for both would depend on air tightness.

If you have gas heating, then compressor based, in a CH room is usually cheaper for drying clothes.

wittynamegoeshere

A heat pump tumble dryer does not involve the air in the room at all.  I think some mistakenly think it's like a heat pump heating system and it somehow steals heat from the room, but that's a misunderstanding.

It's a closed circuit, basically the air goes round and round inside it.  The air goes through the warm side of the heat pump, this warmed air blows through the clothes, picking up the moisture, then it goes through the cold side at which point the water condenses out and gets collected and occasionally pumped down the drain, then this cooler dry air goes back through the warm side, round and round for ever.  The air in the drum at the end is the same air that was in there at the start, but all the moisture has been evaporated into it then condensed out of it, repeatedly.

Ours has a vent on the front, but I think this is only used to cool the outside of the components.  No steam ever comes out of it.  The washing goes in with perfumed fabric conditioner and comes out smelling of not very much, presumably the perfume gets condensed and pumped down the drain, as you never smell it coming out of the machine.

The only possible source of moisture is that we do leave the door open between loads, otherwise it can get whiffy.  So you get one drum-full of dampish air after each load.  But this isn't a big deal, it's already done its cool down cycle by this point so you don't get clouds of steam out of it.

If you cobble together drying racks, heaters, fans and dehumidifiers then what you're actually doing is building a very big and inefficient heat pump tumble dryer, one where you happen to also sit inside the drum!

Qyburn

Specifications for heat pump tumble dryers usually say they can only operate at 10 Deg C or above.  Thats one reason we don't have one, even though the energy saving looks attractive.