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Author Topic: Could you use central heating radiators and pipes to COOL your house in summer?  (Read 41246 times)

sooyeah

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I would like to know if it would be possible to run Cold water through your central heating system?

Doing so would cool the air around the radiator.
If you connected a fan/vent system to either move the hot air from above to the radiator or just found a way to move the air around the room; the effect should work to reduce the overall temperature in the room.

I don't know how effectively you could regulate the temperature. It certainly would be a less environmentally damaging way of cooling a building, if for no other reason than, it might be possible just to add a few componets to existing central heating systems. You certainly would not have hot air thrown out of the building as you do now with air conditioners.

There may be problems with the changing temperatures and the pipe work, and the cooling process may be slightly slower than air con, but it would be cheep and easy(hopefully).

So would it work?

« Last Edit: 09/10/2007 08:35:38 by chris »


 

Offline lightarrow

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I would like to know if it would be possible to run Cold water through your central heating system?

Doing so would cool the air around the radiator.
If you connected a fan/vent system to either move the hot air from above to the radiator or just found a way to move the air around the room; the effect should work to reduce the overall temperature in the room.

I don't know how effectively you could regulate the temperature. It certainly would be a less environmentally damaging way of cooling a building, if for no other reason than, it might be possible just to add a few componets to existing central heating systems. You certainly would not have hot air thrown out of the building as you do now with air conditioners.

There may be problems with the changing temperatures and the pipe work, and the cooling process may be slightly slower than air con, but it would be cheep and easy(hopefully).

So would it work?


I would answer you if I could understand what you want to say; maybe it's my non perfect knowledge of english; can you be more precise?
 

Offline DoctorBeaver

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I think he's asking if cold water could be pumped through central heating radiators to produce a cooling effect, as opposed to hot water warming the room.
 

sooyeah

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I think he's asking if cold water could be pumped through central heating radiators to produce a cooling effect, as opposed to hot water warming the room.

That's exactly what I am asking.

But clearly air cools and falls so you would need a way to move the air around the room. Bringing the hot air to the radiator to cool it would probably work best(so you would suck the air above to the radiator) gradually the air in the room should be cooler surely?
« Last Edit: 20/09/2007 12:52:16 by sooyeah »
 

Offline Karen W.

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Is that not what a swamp cooler does ? Is that different?
 

sooyeah

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Is that not what a swamp cooler does ? Is that different?

What is a swamp cooler?
 

Offline Karen W.

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Doesn't it blow air through a water like saturated filter or panel so when water evaporates from panels you get cool moist air right??? 
« Last Edit: 20/09/2007 13:44:31 by Karen W. »
 

Offline Karen W.

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Here they set up or hang from your ceilng water is used to pump small amounts in! as above if I am right!
 

sooyeah

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Doesn't it blow air through a water like saturated filter or panel so when water evaporates from panels you get cool moist air right??? that 
Here they set up or hang from your ceilng water is used to pump small amounts in! as above if I am right!

You mean an Emerson cooler they suck air through a wet filter. No totally different, didn't know they were called swamp coolers in the states though, so I learnt something new today; Thankyou karen.
 

Offline eric l

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The main problem when using a central heating system for cooling is that radiators are designed to radiate heat.  They can do so because their temperature is higher than the surroundings, so they emit a net heat radiation.
If you run cold water through your central heating system, the radiators will absorb heat radiation from the surroundings, but these surrounding are not designed to radiate.  You will have some cooling of the air between the panels of the radiator, which will make that air heavier and create a circulation, but for a same absolute temperature difference between radiator and surroundings, the yield (= heat transfer) will be lower.
A second point is that because of the cooling of the air, you will have condensation of water on radiator panels.  Airco installations are designed to deal with this, a central heating system is not, and you'll have your radiators dripping.  Besides, this condensation gives off energy (heat) and will again reduce the effectively of your cooling system.
 

Offline Karen W.

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Doesn't it blow air through a water like saturated filter or panel so when water evaporates from panels you get cool moist air right??? that 
Here they set up or hang from your ceilng water is used to pump small amounts in! as above if I am right!

You mean an Emerson cooler they suck air through a wet filter. No totally different, didn't know they were called swamp coolers in the states though, so I learnt something new today; Thankyou karen.

Your welcome I know very little about them.. the exact process I am not sure of someone more qualified then me could probably explain properly.. I am probably wrong anyway.
 

sooyeah

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Doesn't it blow air through a water like saturated filter or panel so when water evaporates from panels you get cool moist air right??? that 
Here they set up or hang from your ceilng water is used to pump small amounts in! as above if I am right!

You mean an Emerson cooler they suck air through a wet filter. No totally different, didn't know they were called swamp coolers in the states though, so I learnt something new today; Thankyou karen.

Your welcome I know very little about them.. the exact process I am not sure of someone more qualified then me could probably explain properly.. I am probably wrong anyway.

I know the system your talking about your not wrong.
« Last Edit: 20/09/2007 14:06:25 by sooyeah »
 

sooyeah

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The main problem when using a central heating system for cooling is that radiators are designed to radiate heat.  They can do so because their temperature is higher than the surroundings, so they emit a net heat radiation.
If you run cold water through your central heating system, the radiators will absorb heat radiation from the surroundings, but these surrounding are not designed to radiate.

What are you saying exactly? it could damage the wall and floor?

You will have some cooling of the air between the panels of the radiator, which will make that air heavier and create a circulation, but for a same absolute temperature difference between radiator and surroundings, the yield (= heat transfer) will be lower.

Yes, but it would only affect the air at and slightly above the radiator leaving the hottest air at the top of the room alone.

A second point is that because of the cooling of the air, you will have condensation of water on radiator panels.  Airco installations are designed to deal with this, a central heating system is not, and you'll have your radiators dripping.

i'm sure that could be easily solved, you could just save the water in a little tank below the radiator.

Besides, this condensation gives off energy (heat) and will again reduce the effectively of your cooling system.

Ok but, surely if the cold water flows through the system the effect would be reduced? The temperature of the radiator would relatively remain the same?

So I think your saying, "it could work but you'll need to redesign a whole new system" that's normal though, surely?

I thought it might be possible to add things to existing systems on the cheep and save money(silly really), So basically you would need to design a whole new combined heating and cooling system for it to work properly?
« Last Edit: 20/09/2007 13:55:10 by sooyeah »
 

Offline kdlynn

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plus there's the cost of keeping the water cold enough to make any difference. water heats up pretty quickly
 

sooyeah

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plus there's the cost of keeping the water cold enough to make any difference. water heats up pretty quickly

The water would be in motion so the heat would be dispersed. That is a good question though, how much electricity would it need, compared to air con? I refuse to believe it would use more than air con.

It would be an enclosed system so it should not effect the environment that much.

Eric are you saying that it would effectively remove water from the air as well?
 

Offline eric l

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Eric are you saying that it would effectively remove water from the air as well?

Hotter air can contain a lot more water in gas phase.  The ratio between the amount present and the maximum amount at that temperature is the relative humidity.  If you cool the air, you reach a temperature where the amount present is equal to that maximum amount, and this is the dew point.  At this point, the relative humidity is 100 %.
See also :  http://en.wikipedia.org/wiki/Humidity
 

Offline Bored chemist

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Just for the record radiators don't do a lot of radiating. Almost all the heat transfer is by convection.
You could run cold water through the same pipes and radiators and get an effect. There are 2 problems what do you do with the water fater it warms up (or equivalently, how do you cool it back down again) and 2 the heat transfer from radiators is typically from a radiator at about 60C to a room at about 20 so there's a 40 degree difference. With a "cold" radiator you would need to chill the radiators below freezing to get the same rate of heat transfer.

There's another problem too. If the radiators were cool enough, water would condense out onto them and drip off causeing damage to carpets etc and corrosion of the pipes etc.
 

sooyeah

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Just for the record radiators don't do a lot of radiating. Almost all the heat transfer is by convection.

I know, I was hoping that convention could work the other way to; the only problem is hot air rises and cold air falls.

You could run cold water through the same pipes and radiators and get an effect. There are 2 problems what do you do with the water fater it warms up (or equivalently, how do you cool it back down again)

If the water was flowing through the system there would obviously be a section that had cooled the water down in the first place, so it would be re-cooled on passing through it.

and 2 the heat transfer from radiators is typically from a radiator at about 60C to a room at about 20 so there's a 40 degree difference. With a "cold" radiator you would need to chill the radiators below freezing to get the same rate of heat transfer.

That is relative to the temperature of the room. Actually you would need to do some experiments to see how great the temperature reduction would be. I think it would be silly to have a freezing cold radiator, you can just see the headline 'little child gets tongue suck'. Not forgetting that, frozen water will not flow. :)   

There's another problem too. If the radiators were cool enough, water would condense out onto them and drip off causeing damage to carpets etc and corrosion of the pipes etc.

Eric was making the same point, but I don't think it would be too difficult to find a way of collecting the water. With regards to the pipe work, you would just need to place a thin cover over the pipes to prevent the air from condensing around them.
« Last Edit: 21/09/2007 11:56:16 by sooyeah »
 

Offline Carolyn

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I would like to know if it would be possible to run Cold water through your central heating system?

Doing so would cool the air around the radiator.
If you connected a fan/vent system to either move the hot air from above to the radiator or just found a way to move the air around the room; the effect should work to reduce the overall temperature in the room.

I don't know how effectively you could regulate the temperature. It certainly would be a less environmentally damaging way of cooling a building, if for no other reason than, it might be possible just to add a few componets to existing central heating systems. You certainly would not have hot air thrown out of the building as you do now with air conditioners.

There may be problems with the changing temperatures and the pipe work, and the cooling process may be slightly slower than air con, but it would be cheep and easy(hopefully).

So would it work?



Hi Sooyeah. What you're describing sounds like a water source heatpump, I think.  Here are a few links that describe them.

http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12640

http://www.toolbase.org/Technology-Inventory/HVAC/water-cooled-evaporative-air-conditioning
 

sooyeah

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Hi Sooyeah. What you're describing sounds like a water source heatpump, I think.  Here are a few links that describe them.

Hi carolyn thanks for the links.

http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12640

Thats very interesting but very different to what I'm talking about. That system uses water pipes to either capture the heat or cold from the ground. Its dispersered in the home very differently as well, looking at what I saw, but maybe you could combine them?
It would probably be a cheaper way of cooling the water.

http://www.toolbase.org/Technology-Inventory/HVAC/water-cooled-evaporative-air-conditioning

That is the swamp cooler karen was talking about.

Thanks for the links.
 

Offline Soul Surfer

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It is best to use circulating air rather than water with a heat pump system because of the need to dry the air to avoid condensation  This is usually done by cooling the air initially a lot cooler than you need to and allowing it to warm up a little before you use it.  The true heat pump system takes heat from the ground or some other reservoir in winter and puts it back in the summer and can be overall considerably more efficient than direct heating and cooling.
 

lyner

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'Swamp coolers' work very well when you are in a hot and DRY climate. Once the air has passed over the wet straw / fabric or equivalent its temperature is significantly lower and its humidity is higher  (the latent heat of vaporisation was responsible for that) but still comfortable. At the place I worked, they tried using one to deal with a summer heatwave in Surrey. It was hopeless - the air started off as almost saturated and ended up totally saturated.  The room was hardly any cooler but even more SWEATY. A dead loss.
Great for the Sahara, I should imagine.
 

sooyeah

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It was hopeless - the air started off as almost saturated and ended up totally saturated.  The room was hardly any cooler but even more SWEATY. A dead loss.
Great for the Sahara, I should imagine.

Been there too, they are not for use in wet countries me feels; Great smell too.

It is best to use circulating air rather than water with a heat pump system because of the need to dry the air to avoid condensation  This is usually done by cooling the air initially a lot cooler than you need to and allowing it to warm up a little before you use it.  The true heat pump system takes heat from the ground or some other reservoir in winter and puts it back in the summer and can be overall considerably more efficient than direct heating and cooling.

They did say on that site that the heat pump is a far more environmental system. But sadly I don't think it's that cheep.
What I am suggesting could be really cheep and replace air con. But to do it properly you would need to redesign the whole system to cope with the problems created by running cold water through the pipes.
At worst without redesigning the whole system you should get a small temperature decrease which would make the home a more comfortable place to live(with wet carpets), compared to not having anything at all.
 

lyner

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Your proposed system would have the effect of lowering the humidity, too. Good value.
 

sooyeah

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Your proposed system would have the effect of lowering the humidity, too. Good value.


Cool, I am not currently jigging around the room.  :)
 

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