Coping with heat

Kitty said:
I know, but I was talking about temperature perception. That is a very different thing, as people who've been through the menopause will tell you. Possibly in more detail and at greater length than seems necessary.

Besides which, even non-menopausal humans aren't great at sensing tiny temperature changes, so even if the fridge/freezer raised the temperature in the whole kitchen by a third of a degree (which it doesn't), it'd make no difference to my comfort.

The small patch of air warmed by the fridge/freezer isn't the cause of the uncomfortable temperature in the kitchen anyway, as evidenced by the drop in the thermometer reading as soon as the real problem dips below the horizon.

So it does make sense to freeze ice packs if heat from the sun's making me feel unwell and overheated. The net gain in comfort is substantial, and that's without taking into account that 90% of the time I'm not even in the same room as the freezer.

If you were talking about the problem of superfluous heat generated by cats, I'd be with you all the way. They're ridiculously hot and they keep trying to sit on you.
Click to expand...
And I’m not sure putting (a small number of) ice packs in a freezer already running cause it to increase its temperature emissions significantly, certainly as long as they are as cold as they can be going in and they could be put in early evening in case a ‘ticking over’ freezer having to chill those does have to up its activity for a short few hours (ice cubes freeze in my mini fridge in a few hours as long as it’s not got frost build up)

at the end of the day you do have to have things in your freezer anyway for it to work best.

and if it’s a concern then I’ve ice packs that are so thin it really is less than ice cube thickness and they freeze fast due to surface area.

leaving the door open for much time when getting things in and out seems a different kettle of fish hence it can do that sound as if it’s having to step up after you’ve closed the door
 
Last edited:
I think the biggest problems for me isn’t a freezer but the laptop I have always on in my room. (It serves many automatic functions for me and my family akin to a server which means it practically needs to always be on). ie. cloud storage, media library and playback, data syncing etc.

Anyways. I’d imagine that leads to a quite a little extra heat. I played around with it in the past and added some things like GPU hardware acceleration etc. So it’s heat efficient to the point I never hear the fan turn on. But I imagine it’s still radiating a significant amount given it’s in small room with me and no AC.
 
bobbler said:
And I’m not sure putting (a small number of) ice packs in a freezer already running cause it to increase its temperature emissions significantly,
Click to expand...
It's a matter of relative thermal masses. The freezer simply pumps heat from the ice packs inside the freezer to the air outside the freezer, plus adds some extra heat due to inefficiency, so you never reduce the total heat in the house. A small ice pack in a large house won't make a noticeable difference. If you were trying to freeze buckets of water in a small room, you might notice the increase in temperature. Expanding the total system (frequent door openings, poorly insulated south wall with big window and lots of sunshine, etc) makes small additions to heat less of a factor.

I live in a small well-insulated space, so I'm quite aware of heat management, even of sources that most people wouldn't notice.

I'm off-grid with a small solar system, so I don't have a fridge or freezer. I keep my food chilled by putting containers of water outside in the evening and swapping them in my insulated food chest. Even in the hottest part of summer, I can keep my perishables below 15C that way. FWIW, meat usually lasts at least 2 weeks that way. Free ice from the sky (hail) is a bonus.

It was -3C this morning.
 
I've read experiences of some people buying "cooling vests" and they work well for some people. There are a few available on Amazon.

Another thing that sounds good is cooling blankets for dogs. They can be used to help humans too if put into a bed for sleeping on.

I must admit I've never bought either, but if summers continue to heat up I probably will.
 
Utsikt said:
That is different from trying to reduce the very local heat in the immediate surroundings of your skin.
Click to expand...
Yes. The original comment was about putting ice in front of a fan, but it didn't specify that it was to reduce temperature on skin, rather than cool the room. There are people who would try the latter, because they believe that a fridge somehow creates cold, rather than pumps the heat into the room.
 
Creekside said:
Yes. The original comment was about putting ice in front of a fan, but it didn't specify that it was to reduce temperature on skin, rather than cool the room. There are people who would try the latter, because they believe that a fridge somehow creates cold, rather than pumps the heat into the room.
Click to expand...
I think it’s fair to assume that most people would have the fan blowing in their general direction, but fair enough.

Besides, it’s probably going to cool the room more than the freezer in another room is going to heat your room.

So as you say, the only net heating would be if the cooling apparatus is in the same room as you. Although you might still be able to achieve a net cooling effect in your very immediate surroundings even though the average temp in the room rises.
 
Creekside said:
It's a matter of relative thermal masses. The freezer simply pumps heat from the ice packs inside the freezer to the air outside the freezer, plus adds some extra heat due to inefficiency, so you never reduce the total heat in the house. A small ice pack in a large house won't make a noticeable difference. If you were trying to freeze buckets of water in a small room, you might notice the increase in temperature. Expanding the total system (frequent door openings, poorly insulated south wall with big window and lots of sunshine, etc) makes small additions to heat less of a factor.

I live in a small well-insulated space, so I'm quite aware of heat management, even of sources that most people wouldn't notice.

I'm off-grid with a small solar system, so I don't have a fridge or freezer. I keep my food chilled by putting containers of water outside in the evening and swapping them in my insulated food chest. Even in the hottest part of summer, I can keep my perishables below 15C that way. FWIW, meat usually lasts at least 2 weeks that way. Free ice from the sky (hail) is a bonus.

It was -3C this morning.
Click to expand...

I know and I assumed you did from your previous posts, which was why I didn't explain it. Once they are frozen then unless your freezer has another issue including too full or empty then them being in there or not doesn't make a difference?

Or someone might if they knew the heatwave was coming and had a big freezer that was over-empty freeze a number of the packs before the heatwave begins and so during that time there is little additional cost from just having them in there already frozen?

So your main 'cost' is if there is energy required from the freezer to get them frozen. Which will be partly helped by other items in there, and partly by how well-designed the ice packs are and their temperature before going in. But I think most find it obvious to if they are warm run them under a cold tap/put in shade.

The interesting bit might be looking at the difference however if someone uses less efficient ice-packs or some of the more or less hard to freeze informal options like big bottles or blankets etc.

And as we are interpreting the main 'cost' in terms of heating a room when it is too hot, then as long as you are somewhere there is a cool time in the night where you open the windows to let cooler air in then that would be the time you want that 'work' to either be being done or have just completed.

The issue isn't about the general really of freezing something to cool you, but about the how. And what you use (efficient freezing and lasting cooling of the packs) and how can change the equation/issue? Because really it is about the hot daytime when you want all the cooling and if you've ones that are quick-freezing they can be doing the freezing bit at a point where you can cool the home anyway?

It's interesting because I'm curious whether actually fridges are more of an output of heat vs freezers.
 
Braganca said:
If someone could help you, tape tinfoil to outside of window — the trick is you have to stop the sun before it hits the glass. Once it hits the glass its heating inside air. We are looking into buying external blinds, but they’re expensive. A temporary cheap option would be the tinfoil..
Click to expand...
I was warned not to have reflective foil inside my window in case it overheated the glass and cracked it, so another reason to do this on the outside, not the inside.
 
Shading on the outside of windows is far superior to on the inside. Stop the sun hitting the building and heating it up in the first instance works much better than trying to get cool it down once the sun has hit it and heated it up. There is a reason why dwellings in the tropics tend to have large open (i.e. well ventilated) verandahs, especially on the east and west sides.

Not always practical or cheap in existing structures, especially if not built for managing heat in the first place. But that is what works best.

Either that or crank up the air-con and wear the power bills.
 
Sasha said:
I was warned not to have reflective foil inside my window in case it overheated the glass and cracked it, so another reason to do this on the outside, not the inside.
Click to expand...
Depends on the type of glazing. High efficiency glazing can crack. There are special foils these days for high efficiency glazing, that can be put on the inside.

But make sure the foil you use is suited to your type of glazing.

Someone I know had old style double glazing without issues and it really helped keep the room cooler.

Edit; added two paragraphs
 
Last edited:
bobbler said:
It's interesting because I'm curious whether actually fridges are more of an output of heat vs freezers.
Click to expand...
I think vertical doors (that let cold air whoosh out) vs horizontal ones (chest freezer) makes a bigger difference than fridge vs freezer. Thermoelectric coolers are dramatically less efficient at pumping heat.

Yesterday I decided to play a game on my ~60W computer. My room was 12C when I started, and 14C around 2 hrs later. The increase wasn't due to external heating, and didn't rise further after I turned the computer off, despite sunny weather. This is a really small well-insulated volume, so I do notice heat sources that would be unnoticeable in a larger home.
 
Sasha said:
Maybe glass even 100 years old is more crack-resistant.
Click to expand...
Glass does change over time. Fresh glass is easier to cut cleanly than older glass.

A film might change the number of water molecules on the glass, which changes fracture characteristics. Neat trick: if you need to cut a curved shape out of glass, use ordinary scissors, with the glass held underwater. The glass crumbles rather than shatters. I've done this several times.
 
You must log in or register to reply here.
Back
Top