keitha
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Post by keitha on Dec 5, 2022 13:59:59 GMT
You have to put energy into a kettle to boil water because the steam holds onto the energy, until it condenses when that energy is released as heat. You should find more warm air coming out of a dehumidifier than can be accounted for by the modest electricity consumed.This sounds like alchemy and too good to be true!  If the heat energy coming out really can exceed "the modest electrical energy consumed", why aren't we distributing wet washing in every room and heating our houses with dehumidifiers? This sceptic will take some persuading  The heat pump type work on the same principle as heat pumps for heating the house
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keitha
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2024, hopefully the year I get out of P2P
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Post by keitha on Dec 5, 2022 14:39:14 GMT
Another thing to look for is light bulbs we know incandescent bad but halogens also eat electricity,
and don't be fooled by the they are onb a transformer so are cheaper. 50 watts is 50 watts be it from a 12 Volt transformer or 240 Volt mains
10 50 watt halogens in a kitchen will use 1/2 a unit per hour !
10 5 watt LEDS will use 1/20 of a unit per hour
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Post by overthehill on Dec 5, 2022 14:51:35 GMT
Call me old fashioned but I just use a clothes horse. Bought it from a pound store twenty years ago and it's still going strong.
and an open window. 48 hours all dry even in the frozen north.
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benaj
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Post by benaj on Dec 5, 2022 14:57:49 GMT
I suppose if someone needs lots / certain pieces to dry in less than 24 hours, then a different solution is needed. Some clothes don't require much drying at the end of the "normal" washing cycle,
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registerme
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Post by registerme on Dec 5, 2022 15:23:59 GMT
How much moisture are we talking about? I mean for example my clothes horse is kept in the kitchen. I wonder how it compares to the kettle boiling multiple times a day and / or pots and pans on the stove? And apparently a person breathes out about 400g of water vapour a day (granted, not likely to be in one place)...
EDIT: Obviously it will depend to an extent on your circumstances eg if you're very sporty, or have a bunch of school age children and no outside space, your drying needs are going to be very different to those of a single adult with a garden.
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littleoldlady
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Post by littleoldlady on Dec 5, 2022 21:50:54 GMT
Another thing to look for is light bulbs we know incandescent bad but halogens also eat electricity, and don't be fooled by the they are onb a transformer so are cheaper. 50 watts is 50 watts be it from a 12 Volt transformer or 240 Volt mains 10 50 watt halogens in a kitchen will use 1/2 a unit per hour ! 10 5 watt LEDS will use 1/20 of a unit per hour I agree that LEDs are very cost effective but I doubt you will get the same amount of lumens out of a 5W LED as a 50W halogen. The ratio is more likely to be about 5:1 rather than 10:1. Also, if you have as many as 10 bulbs in one room they are almost certainly low voltage and LEDs don't always work on the same transformers as the halogens so it may not be as simple as replacing bulbs. I advise trying one before buying ten.
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Post by bracknellboy on Dec 5, 2022 22:26:14 GMT
Another thing to look for is light bulbs we know incandescent bad but halogens also eat electricity, and don't be fooled by the they are onb a transformer so are cheaper. 50 watts is 50 watts be it from a 12 Volt transformer or 240 Volt mains 10 50 watt halogens in a kitchen will use 1/2 a unit per hour ! 10 5 watt LEDS will use 1/20 of a unit per hour I agree that LEDs are very cost effective but I doubt you will get the same amount of lumens out of a 5W LED as a 50W halogen. The ratio is more likely to be about 5:1 rather than 10:1. Also, if you have as many as 10 bulbs in one room they are almost certainly low voltage and L EDs don't always work on the same transformers as the halogens so it may not be as simple as replacing bulbs. I advise trying one before buying ten. While the same transformer may work with LEDS, depending on what type it is, if it is not a recent one designed for both, it is quite likely that they will work particularly inefficiently. So your 5w bulb may in fact be chewing up 15-20w or more as an 'installation'. Plus as you say the like for like lumen output is also a problem. And its not just Lumen, but depending on your application you may want to be considering the light colour as well. As I understand it, and happy to be corrected, there is an issue with current specifications that means that the 'cleaner' light you get from cool light bulbs takes more energy for the same 'standard measured' lumen than it does for warm. And with the re-baselining of energy efficiency for bulbs, that is creating some issues (such as 'cool' 4000k+ LED downlights disappearing from availability because on the 'test' they don't rate as efficient). I had this issue to consider in my bathroom as I was keen to get away from a bunch of 50w 12v halogen downlights and replace with LEDs. I also wanted to increase the perceived 'brightness'. Compared with this, replacing my kitchen 240v halogen downlights was a no-brainer. I learnt that for LEDs, 230/240v was much better territory than 12v when it came to lumen output per pound. Plus the issues with transformer. In the end, I took the decision that it made far more sense to rip out the 12v transformers and switch the lot over to 230/240v GU10 lampholders. I also managed to source some Philips LEDs that were in the 4000k+ temp range that were clearly being withdrawn from manufacture given they were disappearing off the face of the planet.
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Post by bernythedolt on Dec 6, 2022 0:20:58 GMT
I was hoping to put some numbers to this, but you've beaten me to it. Taking your house as a closed system, the net effect energy-wise is that you will consume an additional 250Wh every hour, or 6kWh per day. In return, moving the condensate to the appliance itself and away from walls/windows should help combat the damage from condensation... at a cost. littleoldlady , I see where you're coming from now - apologies for flippancy. The point that littleoldlady was making though was what about the release of latent heat energy resulting in a heating benefit. In the case above (which of course is very wet finger in the air numbers, since it depends on the actual extraction rate for any given operating environment) the 'on the face of it' numbers is a net gain of approx 100Wh during running [340Wh for 250 input]. Which means you could reduce consumption from your core heating source. I'm dubious you'll actually get that performance (apart from the fact it's entirely possible I've made fundamental errors in my calculations) though, as it is using the stated extraction rate which is likely to be for the optimal operating conditions (and which will require a higher ambient temperature to boot). Its all a touch academic however (albeit interesting) at this specific time: While figuring out whether its worth getting one and what type, the only ones which were attractive have now gone out of stock at the places I was looking (or perhaps a 5 week delivery time). Serves me right, but then it may only have happened as I added one to a basket. There's no significant heating benefit that I can discern. That 'bonus' 90Wh you've calculated as the latent heat emitted by condensation will still be delivered within the fabric of the house, whether the condensation takes place on the walls & windows or within a dehumidifier. I can accept that some of it will escape the fabric of the house somewhat sooner in the former case than the latter, but I doubt the overall net effect is anything like a 90Wh gain. But even if there were 90Wh gain, how significant is that? It's completely trivial. Think, by how much would a 100W incandescent lightbulb raise the temperature of a house? The manufacturer EBAC claims a heat recovery figure of about 4,500 BTUs over a full day. Sounds impressive? An average person at rest gives off something approaching 8,000 BTUs over a full day. (And we all believe manufacturers' claims, obvs... ). 4,500BTUs is ~1.3kWh. Running the appliance for a full day would consume 6kWh. That's a net consumption, not a net gain. So that's 1.3kWh recovered... but you need more than 20 times that to heat an average house. Then you have to add the additional cost of running the appliance (I suspect the manufacturer may be ignoring this cost in their calculations). I'm forced to conclude the heat recovery benefit of a dehumidifier is completely trivial. It strikes me that if you need to dry the air to combat damp problems, then a dehumidifier is beneficial, but from the point of view of the core heating system, the only reason you may just about be able to turn it down is because you've just installed an appliance consuming 0.25kWh every hour into the mix and most of that 0.25kWh will be dissipated as heat energy warming the air inside the house.
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Post by bracknellboy on Dec 6, 2022 8:04:19 GMT
The point that littleoldlady was making though was what about the release of latent heat energy resulting in a heating benefit. In the case above (which of course is very wet finger in the air numbers, since it depends on the actual extraction rate for any given operating environment) the 'on the face of it' numbers is a net gain of approx 100Wh during running [340Wh for 250 input]. Which means you could reduce consumption from your core heating source. I'm dubious you'll actually get that performance (apart from the fact it's entirely possible I've made fundamental errors in my calculations) though, as it is using the stated extraction rate which is likely to be for the optimal operating conditions (and which will require a higher ambient temperature to boot). Its all a touch academic however (albeit interesting) at this specific time: While figuring out whether its worth getting one and what type, the only ones which were attractive have now gone out of stock at the places I was looking (or perhaps a 5 week delivery time). Serves me right, but then it may only have happened as I added one to a basket. There's no significant heating benefit that I can discern. That 'bonus' 90Wh you've calculated as the latent heat emitted by condensation will still be delivered within the fabric of the house, whether the condensation takes place on the walls & windows or within a dehumidifier. I can accept that some of it will escape the fabric of the house somewhat sooner in the former case than the latter, but I doubt the overall net effect is anything like a 90Wh gain. But even if there were 90Wh gain, how significant is that? It's completely trivial. Think, by how much would a 100W incandescent lightbulb raise the temperature of a house? The manufacturer EBAC claims a heat recovery figure of about 4,500 BTUs over a full day. Sounds impressive? An average person at rest gives off something approaching 8,000 BTUs over a full day. (And we all believe manufacturers' claims, obvs... ). 4,500BTUs is ~1.3kWh. Running the appliance for a full day would consume 6kWh. That's a net consumption, not a net gain. So that's 1.3kWh recovered... but you need more than 20 times that to heat an average house. Then you have to add the additional cost of running the appliance (I suspect the manufacturer may be ignoring this cost in their calculations). I'm forced to conclude the heat recovery benefit of a dehumidifier is completely trivial. It strikes me that if you need to dry the air to combat damp problems, then a dehumidifier is beneficial, but from the point of view of the core heating system, the only reason you may just about be able to turn it down is because you've just installed an appliance consuming 0.25kWh every hour into the mix and most of that 0.25kWh will be dissipated as heat energy warming the air inside the house. I agree its completely trivial: nobody is saying otherwise. Indeed doing the (very rough and ready) calculation demonstrates it is trivial, which was the point of the exercise.
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littleoldlady
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Post by littleoldlady on Dec 6, 2022 9:08:42 GMT
The point that littleoldlady was making though was what about the release of latent heat energy resulting in a heating benefit. In the case above (which of course is very wet finger in the air numbers, since it depends on the actual extraction rate for any given operating environment) the 'on the face of it' numbers is a net gain of approx 100Wh during running [340Wh for 250 input]. Which means you could reduce consumption from your core heating source. I'm dubious you'll actually get that performance (apart from the fact it's entirely possible I've made fundamental errors in my calculations) though, as it is using the stated extraction rate which is likely to be for the optimal operating conditions (and which will require a higher ambient temperature to boot). Its all a touch academic however (albeit interesting) at this specific time: While figuring out whether its worth getting one and what type, the only ones which were attractive have now gone out of stock at the places I was looking (or perhaps a 5 week delivery time). Serves me right, but then it may only have happened as I added one to a basket. There's no significant heating benefit that I can discern. That 'bonus' 90Wh you've calculated as the latent heat emitted by condensation will still be delivered within the fabric of the house, whether the condensation takes place on the walls & windows or within a dehumidifier. I can accept that some of it will escape the fabric of the house somewhat sooner in the former case than the latter, but I doubt the overall net effect is anything like a 90Wh gain. But even if there were 90Wh gain, how significant is that? It's completely trivial. Think, by how much would a 100W incandescent lightbulb raise the temperature of a house? The manufacturer EBAC claims a heat recovery figure of about 4,500 BTUs over a full day. Sounds impressive? An average person at rest gives off something approaching 8,000 BTUs over a full day. (And we all believe manufacturers' claims, obvs... ). 4,500BTUs is ~1.3kWh. Running the appliance for a full day would consume 6kWh. That's a net consumption, not a net gain. So that's 1.3kWh recovered... but you need more than 20 times that to heat an average house. Then you have to add the additional cost of running the appliance (I suspect the manufacturer may be ignoring this cost in their calculations). I'm forced to conclude the heat recovery benefit of a dehumidifier is completely trivial. It strikes me that if you need to dry the air to combat damp problems, then a dehumidifier is beneficial, but from the point of view of the core heating system, the only reason you may just about be able to turn it down is because you've just installed an appliance consuming 0.25kWh every hour into the mix and most of that 0.25kWh will be dissipated as heat energy warming the air inside the house. I think this discussion has run its course. We all seem to agree that there is a small gain from the release of latent heat into warm air instead of escaping through cold glass, but the main advantage of a dehumidifier is reduced condensation and subsequent mould. One final point, the electricity consumed by the dehumidifier motor and compressor (6KWh/day you say) will all be turned into useful heat so if the house is heated by electricity there is no running cost associated with the dehumidifying process, and now that the price of gas has soared (currently disguised by government decree but not for long) even in a gas heated house the net cost of running the unit will be low, if it is run when the heating is on. My conclusion is that they are very useful devices and ideally would be built into all new build homes.
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adrianc
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Post by adrianc on Dec 6, 2022 9:18:38 GMT
Another thing to look for is light bulbs we know incandescent bad but halogens also eat electricity, and don't be fooled by the they are onb a transformer so are cheaper. 50 watts is 50 watts be it from a 12 Volt transformer or 240 Volt mains 10 50 watt halogens in a kitchen will use 1/2 a unit per hour ! 10 5 watt LEDS will use 1/20 of a unit per hour I agree that LEDs are very cost effective but I doubt you will get the same amount of lumens out of a 5W LED as a 50W halogen. The ratio is more likely to be about 5:1 rather than 10:1. Also, if you have as many as 10 bulbs in one room they are almost certainly low voltage and LEDs don't always work on the same transformers as the halogens so it may not be as simple as replacing bulbs. I advise trying one before buying ten. Understanding basic physics, and what a watt is, certainly makes a big difference when it comes to reducing electricity consumption. As far as LEDs goes - I just had a bulb go in my office. Surprisingly, it was still an old-school filament, 60W! It's been replaced with an 8W LED, and it's brighter (a bit too bright). We have 11 spots in our kitchen - 230v, all LED...
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Post by Ton ⓉⓞⓃ on Dec 6, 2022 9:51:18 GMT
I had one back in the 80's. As I recall very cold liquid is pumped through coils at the back and this causes moisture in the air to condense and freeze on the outside of the coils. Then warm liquid gets pumped through the coils and the frozen condensate melts and drips into the collection bin. Got rid of it when I had double glazing and cavity wall insulation installed.
I'm far too lazy to mess around when drying cloths. I set the washer / dryer to iron dry (which doesn't take a lot longer than just wash), and when it comes out damp I hang it up in the living room for 30 minutes and it's dry.
Sounds better your way  Was also going to mention mrs macq's Tit-bits tip of the week (for people of a certain age) about using the drying balls that you put in a tumble dry but even less sure of that science
Despite the name drying balls I think they are for towels I'm told they make them softer not drier
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registerme
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Post by registerme on Dec 6, 2022 10:04:50 GMT
We have 11 spots in our kitchen - 230v, all LED... I have over a hundred ceiling mounted spots in my place. I had all of the halogen bulbs replaced by LEDs back at the start of... 2020(?). I'm very glad I did!
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Post by Ton ⓉⓞⓃ on Dec 6, 2022 10:18:30 GMT
Call me old fashioned but I just use a clothes horse. Bought it from a pound store twenty years ago and it's still going strong. And if need be you can always extract the latent heat energy in the wood by setting it on fire
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Post by bracknellboy on Dec 6, 2022 10:38:05 GMT
Call me old fashioned but I just use a clothes horse. Bought it from a pound store twenty years ago and it's still going strong. And if need be you can always extract the latent heat energy in the wood by setting it on fire I think ours is plastic and metal, so that's not going to end well.
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Was also going to mention mrs macq's Tit-bits tip of the week (for people of a certain age) about using the drying balls that you put in a tumble dry but even less sure of that science