the physics of manflu...
Discussion
It's a long time since I studied physics and thermodynamics, so I need some external input here.
those days when you have manflu and are lying on the sofa 'dying' and have a squillion duvets to keep you from suffering from frostbite, does the tog rating of the duvets make any difference to how warm you are?
so, if you had a tog 10 and a tog 13.5 which would be better to place closest to your body, or would it not make a difference? supposing then you added a third duvet, one with greater heat retaining properties than the other two, would that be better on the top, in the middle, or closer to your skin?
I know, hardly a car related topic, save for the fact the thickest duvet has a picture of a Morgan on it and I think that I'm coming down with flu, so this matters to me.
Cheers
those days when you have manflu and are lying on the sofa 'dying' and have a squillion duvets to keep you from suffering from frostbite, does the tog rating of the duvets make any difference to how warm you are?
so, if you had a tog 10 and a tog 13.5 which would be better to place closest to your body, or would it not make a difference? supposing then you added a third duvet, one with greater heat retaining properties than the other two, would that be better on the top, in the middle, or closer to your skin?
I know, hardly a car related topic, save for the fact the thickest duvet has a picture of a Morgan on it and I think that I'm coming down with flu, so this matters to me.
Cheers
Lemmonie said:
I have the answer.
You have the lighter (smaller tog) ones on first close to you as they are lighter. Then the heavy ones on top so that they squish the others closer to you.
What do I win?
A duvet works by trapping air, which is a really good insulator. If you squash them down they don't insulate as well. In general the difference between a 5 TOG and 15 TOG is the thickness, the insulation per inch is going to be similar so the order you put them on won't make much difference.You have the lighter (smaller tog) ones on first close to you as they are lighter. Then the heavy ones on top so that they squish the others closer to you.
What do I win?
Heat transfer through a material is dependant on the thickness. Multiple layers of different thicknesses of a single material provide the same insulation regardless of the order they are fitted in.
Also "manflu" doesn't exist. The awesome skill of women to work as normal while infected with flu is because what they actually have is a cold.
Also "manflu" doesn't exist. The awesome skill of women to work as normal while infected with flu is because what they actually have is a cold.
Captain Muppet said:
Heat transfer through a material is dependant on the thickness. Multiple layers of different thicknesses of a single material provide the same insulation regardless of the order they are fitted in.
Also "manflu" doesn't exist. The awesome skill of women to work as normal while infected with flu is because what they actually have is a cold.
Surely it is only partially dependent upon thickness, I am sure U value comes into it somewhere - bloody hell I am clearly also crushingly dull. Also "manflu" doesn't exist. The awesome skill of women to work as normal while infected with flu is because what they actually have is a cold.
OP I apologise most profusely.
It came as some relief when my OH got flu for the first time recently. She was out of action for week and not fully recovered for another two weeks. I had the same thing but managed to function, just! I now have a benchmark I that I can use after all these years of her believing I was just a softie.
I believe it is better to have the higher tog rated duvet closest to you, with the remainder in descending order of rating.
This is because the higher tog rated will provide the best insulating barrier, trapping warm air clostest to your body. The subsequent layers will provide further insualting, but trapping the air between the current and previous duvet.
Imagine a three-storey house with underflooring heating on the ground floor only. Between each floor is insulation, the thickest between ground and first, then slightly thinner between first and second etc.
The majority of the heat will be trapped at ground floor (assume 50%), then 50% travels upto the first floor, rising up through to the second floor, trapping 25% and finally through the third floor trapping 12.5%.
Therefore, 50% of the heat is trapped on the ground floor (the area closest to your body), then 25% between the next two duvets and 12.5% between the final two.
(For clarity, heat loss through building fabric has been ignored).
That is how I view it anyway, happy to be corrected
This is because the higher tog rated will provide the best insulating barrier, trapping warm air clostest to your body. The subsequent layers will provide further insualting, but trapping the air between the current and previous duvet.
Imagine a three-storey house with underflooring heating on the ground floor only. Between each floor is insulation, the thickest between ground and first, then slightly thinner between first and second etc.
The majority of the heat will be trapped at ground floor (assume 50%), then 50% travels upto the first floor, rising up through to the second floor, trapping 25% and finally through the third floor trapping 12.5%.
Therefore, 50% of the heat is trapped on the ground floor (the area closest to your body), then 25% between the next two duvets and 12.5% between the final two.
(For clarity, heat loss through building fabric has been ignored).
That is how I view it anyway, happy to be corrected
Poor poorly DMN!
I think the awful feeling is mostly having a high temperature, and therefore the higher tog rating, that'll slow down your heat loss a bit/surround you with nice warm air, will be the one that does the trick. Extra ones over the top if needed because the weight feels sort of reassuring.
Take 2 cocodamol, wait 25 minutes, start removing duvets as your temperature goes down!
I think the awful feeling is mostly having a high temperature, and therefore the higher tog rating, that'll slow down your heat loss a bit/surround you with nice warm air, will be the one that does the trick. Extra ones over the top if needed because the weight feels sort of reassuring.
Take 2 cocodamol, wait 25 minutes, start removing duvets as your temperature goes down!
Funnily enough I too was mulling this over quite recently so conducted an experiment.
On the first night I filled the duvet cover with both a TOG 9 (N=1) and a TOG 10.5. (N=1). Lovely and warm, no problems.
The very next night I removed the TOG 10.5 and laid it on top of the duvet instead and I swear I felt warmer (Could just have been a warmer night though).
I didn't check for correlation though between external duvet TOG and warmth.
On a cold night last year I had a TOG 9 and a TOG 10.5 in the same cover and placed a TOG 13 over the top and was too warm. Go figure!
On the first night I filled the duvet cover with both a TOG 9 (N=1) and a TOG 10.5. (N=1). Lovely and warm, no problems.
The very next night I removed the TOG 10.5 and laid it on top of the duvet instead and I swear I felt warmer (Could just have been a warmer night though).
I didn't check for correlation though between external duvet TOG and warmth.
On a cold night last year I had a TOG 9 and a TOG 10.5 in the same cover and placed a TOG 13 over the top and was too warm. Go figure!
Mobile Chicane said:
Lemmonie said:
I have the answer.
You have the lighter (smaller tog) ones on first close to you as they are lighter. Then the heavy ones on top so that they squish the others closer to you.
What do I win?
Definitely.You have the lighter (smaller tog) ones on first close to you as they are lighter. Then the heavy ones on top so that they squish the others closer to you.
What do I win?
And if you get too hot, remove the heavier ones first.
In terms of squishing the duvet; this actually makes the duvet less thermally efficent. You really want the duvet as 'fluffed up' as possible as this helps trap the warm air.
With regards to removing the heavier ones first; you want to remove the lighter ones first as this will change the thermal efficiency in smaller increments. So if the heaviest duvet is providing 50% of the heat retention and the others in 25%, then you'd be better off removing the lighter ones first until you find a balance in this order:
Assuming 3 duvets, 1 x A (50%), 1 x B (25%) and 1 x C (20%). Percentage relating to thermal efficiency.
So in order of removal if you're starting with them all on:
Starting -
Too hot - (Body) < A < B < C
Too hot - (Body) < A < B
Too hot - (Body) < A
Too hot - (Body) < B < C
Too hot - (Body) < B
Too hot - (Body) < C
Reverse if too cold.
Jesus, this has got geeky. Is it obvious I'm an engineer?
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