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General Science => General Science => Topic started by: sooyeah on 20/09/2007 12:15:18

Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/09/2007 12:15:18
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?

Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lightarrow on 20/09/2007 12:29:42
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?
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: DoctorBeaver on 20/09/2007 12:32:57
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/09/2007 12:46:42
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?
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Karen W. on 20/09/2007 12:51:35
Is that not what a swamp cooler does ? Is that different?
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/09/2007 12:52:58
Is that not what a swamp cooler does ? Is that different?

What is a swamp cooler?
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Karen W. on 20/09/2007 12:54:13
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??? 
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Karen W. on 20/09/2007 12:55:30
Here they set up or hang from your ceilng water is used to pump small amounts in! as above if I am right!
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/09/2007 13:06:28
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: eric l on 20/09/2007 13:27:43
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Karen W. on 20/09/2007 13:42:44
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/09/2007 13:50:38
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/09/2007 13:53:24
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?
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: kdlynn on 20/09/2007 13:54:39
plus there's the cost of keeping the water cold enough to make any difference. water heats up pretty quickly
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/09/2007 14:03:12
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?
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: eric l on 20/09/2007 17:28:10

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
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Bored chemist on 20/09/2007 21:13:39
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 21/09/2007 11:51:21
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Carolyn on 21/09/2007 15:51:44
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
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 21/09/2007 17:10:02
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Soul Surfer on 21/09/2007 20:47:49
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 21/09/2007 23:32:57
'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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 22/09/2007 11:40:30
.
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.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 22/09/2007 11:55:10
Your proposed system would have the effect of lowering the humidity, too. Good value.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 22/09/2007 12:38:15
Your proposed system would have the effect of lowering the humidity, too. Good value.


Cool, I am not currently jigging around the room.  [:)]
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Bored chemist on 22/09/2007 12:51:08
"I know, I was hoping that convention could work the other way to; the only problem is hot air rises and cold air falls."

Convection will run in reverse. The cold air runs down the radiator and onto the floor wher it cools the rest of the room. Meanwhile warm air is drawn down  to the cold radiator.


"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."

I know it would have to be cooled if you were going to recirculate it. What I asked was how you would do that (specifically I said "how do you cool it back down again".

"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. "

Well, that's why I listed that as a potential problem.



One idea that strikes me is that you could use a swamp cooler type arrangement outside to cool a radiator to supply the cold water to circulate through the house radiators.
That gets round the problem that swamp coolers humidify the air- it doesn't matter so much if the air they are humidifying is outside.
It also means that the water can't get colder than the dew point of the air so there won't be a condensation problem.

Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 22/09/2007 13:18:45
"I know, I was hoping that convention could work the other way to; the only problem is hot air rises and cold air falls."

Convection will run in reverse. The cold air runs down the radiator and onto the floor wher it cools the rest of the room. Meanwhile warm air is drawn down  to the cold radiator.

Yes, you bring the hot air to the cold radiator, that way the air will gradually get colder. It compensating for the reverse Convection.

"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."

I know it would have to be cooled if you were going to recirculate it. What I asked was how you would do that (specifically I said "how do you cool it back down again".

Well there are lots of ways to cool water, you could use the heat pump system. I just think which ever way you did do it should use as little electricity as possible, and not dump the heat out side, as air con does.
 
"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. "

Well, that's why I listed that as a potential problem.

One idea that strikes me is that you could use a swamp cooler type arrangement outside to cool a radiator to supply the cold water to circulate through the house radiators.
That gets round the problem that swamp coolers humidify the air- it doesn't matter so much if the air they are humidifying is outside.
It also means that the water can't get colder than the dew point of the air so there won't be a condensation problem.

Except you would need one on every radiator. Or are you thinking that you could have one big-one at a certain point in the chain and that would cool the water down for the whole system? That would expose the water and you would get evaporation and therefore need to top up the water supply consistently.
Overall that would make the system more complex and use more energy surely?

Also condensation has a benefit as you remove water from the air. So I'm thinking that you would just need to design some form of cover to stop people touching it.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: techmind on 04/10/2007 00:50:21
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.
When you complete the picture, what you are describing basically IS an air conditioning system...

In addition to what you've mentioned, you also need a system to cool the water down, as it will otherwise soon reach the temperature of the rooms. So you need a "refridgeration" module. This is a heat pump which pumps the heat-energy out of the water and dumps it into the air outside, the ground, or a convenient pond/lake or something.

As far as I can make out, the installed air-con system at my workplace pumps cooled water around the building. The ceiling-mounted cooling units are special "radiators" but with lots of thin fins to help the heat transfer despite a fairly modest temperature difference between the fins and the air. There's also a fan to circulate the air through the fins of the "radiator" because convection is not really strong enough because the temperature-difference is too small. There's some kind of system to catch the drips of condensation and a pipe to drain them away. Then outside the back of the building is a bank of refridgeration/heat-pump units to cool the water.

Unfortunately there's a very simple theoretical limit on the efficiency of any heat-pump, and for refridgeration device the efficiency rapidly gets worse as the difference increases between the temperature you're trying to cool to and the temperature at which you can dump/sink the heat. Although you might save some infrastructure by re-using existing heating radiator systems, overall the running costs can't be any lower than a dedicated cooling system... and since existing radiators aren't optimised for cooling it'll probably be much less effective and efficient overall. Sorry.

To minimise condensation (which is going to cost a lot of energy but not achieve much cooling) I imagine you'd want to run the water ("radiators") not too much below the target air temperature. This implies that you're going to need forced airflow (fans) to assist the air-circulation around the cold-"radiator" fins.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 05/10/2007 23:13:35
But any system you use for shifting heat away will cost energy / money. The transport method - cold air or cold water  is not really relevant, except to the installer. Unless you live next to the sea or a river, you need a heat pump.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 07/10/2007 01:01:16
Unfortunately there's a very simple theoretical limit on the efficiency of any heat-pump, and for refridgeration device the efficiency rapidly gets worse as the difference increases between the temperature you're trying to cool to and the temperature at which you can dump/sink the heat. Although you might save some infrastructure by re-using existing heating radiator systems, overall the running costs can't be any lower than a dedicated cooling system...

That is debatable. This system could produce an exceptable temperature reduction, using less energy, and removing moisture at the same time.
If you used the heat pump method for the heating and cooling of the water, then you would surely have a greater reduction on the energy used. Heat pumps are recommended because they use less energy; they store the heat and cold and then tap into that save resource as needed.

and since existing radiators aren't optimised for cooling it'll probably be much less effective and efficient overall. Sorry.

I know they are not, that is why you would need a fan system to aid the air flow around the room.

To minimise condensation (which is going to cost a lot of energy but not achieve much cooling)

Is that correct? Condensation will occur naturally and has a benefit of removing moisture from the air(currently a job preformed by a dehumidifier) this system if designed properly could combine central heating, air-conditioning, a dehumidifier and use the heat pump system to heat and cool the water.
It would hopefully be a low energy all-round system.

As you already said you would need less materials to install it, and all the others could be replaced by it, that makes it a far greener system.
You design it to be a low energy system. The only part of the heat pump system you would use would be the heat and cold storage hopefully the main system could work the same as it does today.   

I imagine you'd want to run the water ("radiators") not too much below the target air temperature. This implies that you're going to need forced airflow (fans) to assist the air-circulation around the cold-"radiator" fins.

A small solar powered fan, combined with a funnel could easily do that. However, you may not envision this system as I do, but I don't see any necessity to use electricity from the main grid to run the fans. That again would reduce the energy burden of running the system itself.

I'm actually thinking that you would bring the hot air to the radiator, to below the radiator, it would then naturally rise and cool as it did so.

Thankfully hot and cold water act differently and have different affects on the materals they pass over, valves could be designed to shut and open from the temperature of the water inside the system.
Solar powered fans could be designed to come on only when the temperature of the radiator reached a certain level.
The condensed water could be drained and then stored in a tank, then used as a means to refill the system should it become low, which would reduce the systems overall use of water from the water company.
All these things could be combined to have a low energy system.

I post it for all, it belongs to the people. The Government can pattern it. [;D] I'm sure some science student reading this has already figured out how to work it. Go nuts!!!  [:)]
 
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 07/10/2007 22:30:52
But where is the source of energy to keep the circulating water cool? (Assuming you have no source of already-cooled water). You cannot ignore this  problem.
I was not aware that there is any debate that a heat pump requires more energy input the bigger the target change in temperature. Some basic thermodynamics here, I'm afraid.

Instead of a solar powered electric fan  you could  do what is done in many desert countries - that is to have a central well in a building which acts like a chimney and produces natural circulation (convection) of air, driven by the Sun. Water at the bottom of the column can be evaporated and produce cooling. This is no good in humid areas, though.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Atomic-S on 14/11/2007 04:26:32
I would like to add some insights from Arizona. There are ways of cooling very efficiently if the humidity is not too high. First I will repeat what was said above about the cooling tower effect. That is used here in Arizona to cool outdoor bus stops. Over the structure is a "chimney" containing some kind of filter pads and a pump and a water tank. The pump wets the pads, the pads add moisture to the air, cooling and causing it to condense. The air then falls, causing a light breeze upon the people below. This is not dramatic cooling, but enough to make a difference. The same effect is used in this building where I am: an evaporative "swamp" cooler is on the roof. When the weather requires only a little cooling, the windows are opened up, the machine's pump is turned on but rhe fan left off. The convection caused by the cooler and therefore denser air in the machine draws air downward through it, creating a soft flow of cooled and moister water through the building. The electricity required to run it in this mode is only what is required for a small pump.

Another insight:  The power plant that is or was located here in the city has a section where there are huge fans blowing through some kind of a box. I believe that this is the cooling tower, and I think it basically works as follows:  Hot water from the turbines is sprayed through some kind of filter, air blows, causing part to evaporate and the rest to be cooled substantially, and the cooled water is then returned to the machinery.

Now when it comes to making a really low-electricity-use cooling system, both of these ideas are useful. Dispensing entirely with the radiators, you could have a filter box on the building roof, with the water and pump, and just have that flowing and by convection the wetter air would come down into the building, cooling it. (Windows must be open below).  The pump could e vne be run by solar panels or even a wind turbine. But keep in mind that this may be inadequate if the weather becomes unfavorable in terms of too hot, too humid, or too windy. To turn then to your radiator idea, I think the cheapest way you could supply cooled water to the radiators would be having a unit outside in which the warmer water exiting the radiators would flow into nozzles at the top of a box, then rain down into a collecting area in the bottom, and from thence be recirculated into the radiators again. During its descent, the water droplets would cool by evaporation. Therefore there would be some water loss, which would have to be made up from the city water mains or some source, but this would not be a great cost in most areas.  A fan in the evaprator box might make the process more efficient, but also might be unnecessary if the box were quite tall and there were some light natural breezes.  Because the temperature drop of the water would be modest, the radiators inside would have to have, as has been mentioned, additonal fans to force air through them. I do not know if this system would get cold enough to cause condensation inside; I rather doubt it because the water itself is being cooled by evaporation, so it would not go below the outdoor dew point. Noneetheless, there would be some cooling. This system would be extraordinarily inexpensive to operate, basically you might need no more power than for the water pump and a few small fans. But of course will not produce the cooling power of a more expensive and power guzzling refrigeration system. For this reason, such a cooling system should be accompanied by careful attention to the condition of the building, such as whether the insulation is adequate, the roof painted white, ventilation in the attic or overhead space, trees to shade the structure from the direct sun, etc.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 14/11/2007 22:58:36
Very nice - if you have the right levels of humidity.
In the UK you have to work much harder, nearly every day, to remove heat - it's so sweaty most of the time. It costs you.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Atomic-S on 03/12/2007 01:41:21
In your climate, the big challenge is not so much cooling as dehumidifying. Thus, a significant correllary question to the original one, is, what are the options for dehumidifying cheaply using existing radiators (or perhaps some other means)? Standard refrigeration can do it but that is costly to install and costly to operate.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 06/12/2007 13:53:56
The latent heat of vaporisation  is always going to be the bottom line. There can be  several kg of water to get rid of  from a house full of humid air. That is going to cost a fair bit to remove, however you choose to do it. Air conditioners are not, now, a silly price and achieve the effect more conveniently than ice cold  room radiators. In any case, you would need to have a drainage system to deal with the condensate on the radiators - costly and intrusive. Circulating dried air is much easier.
People should try to get used to humidity - it is very costly ,in carbon, to deal with it.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Atomic-S on 23/12/2007 04:41:51
Unless someone can figure a way to do it with the sun -- by the way, what kind of sunshine do you get there in the UK during that time of year?
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 23/12/2007 23:37:12
A solar powered refrigeration system is not beyond the bounds of possibility.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Atomic-S on 08/01/2008 04:01:37
True, but is there any way to do it at reasonable cost?
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 10/01/2008 16:30:37
An 'absorption' type unit could shift a few hundred watts worth of heat. A 2m reflector, focused on the right part would provide enough power when the Sun was shining. That's when it would be most useful, too. They are not efficient but, with no  moving parts, they last for ever (?) when undisturbed. I had a tiny one in my VW camper and it kept drinks cool. The beauty was that it ran on mains, 12V and camping gaz, silently.
Hardly suitable for keeping a whole house cool, though and useless on long hot nights.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: Nobody's Confidant on 10/01/2008 17:42:07
Well, if you turned off the radiators, there would be an absence of heat. And absence of heat is cold. So yes, technically speaking, using radiators(or rather, NOT using radiators) could cool the house.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 19/04/2008 17:21:46
Well, if you turned off the radiators, there would be an absence of heat. And absence of heat is cold. So yes, technically speaking, using radiators(or rather, NOT using radiators) could cool the house.

You are missing the point, the idea was to pump cold water (very cold water) through the central heating system, to make the radiators colder, and by doing so to cool the room more and maybe remove some moisture too. 
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 19/04/2008 17:52:23
I think we understand your idea. There are just two comments to make (in the context of the UK).
1. You need a refrigeration unit to produce your cold water (unless you live next to a mountain stream). So it costs you.
2. Your radiators will be dripping water all over the floor and may not cool the room very effectively, in any case (they would need to be near the ceiling).

Why do you think it is not done already if it such a good idea?
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/04/2008 12:56:51
I think we understand your idea. There are just two comments to make (in the context of the UK).
1. You need a refrigeration unit to produce your cold water (unless you live next to a mountain stream). So it costs you.
2. Your radiators will be dripping water all over the floor and may not cool the room very effectively, in any case (they would need to be near the ceiling).

Why do you think it is not done already if it such a good idea?

Teathing problems 
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: rosalind dna on 20/04/2008 13:45:14
Why not open the windows instead of using the air-freshenrs, easier and it is free too.

That's what I do every summer, as I get a nice draft through my home.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 20/04/2008 18:49:13
I tend to agree; air con is pretty essential in some countries if you can't build houses in the traditional way but, in the UK, wear shorts and T shirt and ignore the sweat.
As for "teething troubles" has it even been tried?
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: sooyeah on 20/04/2008 19:32:26
I tend to agree; air con is pretty essential in some countries if you can't build houses in the traditional way but, in the UK, wear shorts and T shirt and ignore the sweat.
As for "teething troubles" has it even been tried?

Well exactly.
 
My idea was that cheaply, every home in Britain could have a few modifications done to the central heating system; and hey-presto, a cool home in the summer. Therefore the central heating system is set, it's all add ons.

You could however design a totally new system. But I don't think either idea, has actually been experimented with.
Title: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: lyner on 20/04/2008 20:52:18
Have you ever done any plumbing?
You would have to provide drainage from every radiator in the house; gravity operated would be unlikely to work. How would you arrange for that? And what about the poor efficiency of the system. And have you considered the capital cost plus the running cost, bearing in mind that it would be very inefficient?
The heat circulation system is the least of the problems associated with air con.
Title: Re: Could you use central heating radiators and pipes to COOL your house in summer?
Post by: tanveer10 on 26/08/2013 07:05:56
Hi

I am interested in this topic.

Sooyeah - have you had a chance to experiment some of the suggestions? What was the outcome of the same?

Thanks