Many cities in China have begun to explore district cooling, and in the future, the sight of windows covered with air conditioners may become a rarity in some new residential buildings or commercial properties.
This exists elsewhere and has for decades. I’m not trying to take away from what accomplishments are described in the article, only to say there is a lot of info available. The one I am most familiar with is in Toronto, the Deep Lake Water Cooling System.
Is it really that simple? For one thing you probably don’t want to have the cooling happening through the floor, right? Unlike heated floors which are quite nice i imagine that having really cold floors would get uncomfortable in a living space.
I worked in an industrial facility that used this style of system (switch from hot water to cold water). It was built in the late 1950s. It wasn’t centralized, but had the same end of loop systems. It used radiators.
Also, what do you do with the condensation? Especially in high humidity environments, whenever you cool warm air with a cold surface you will get condensation. That needs to be dealt with somehow in order not to lead to mold.
There is a fan in the radiator cabinet. I think there is a condensate trap too, but don’t quote me on that.
That is one advantage of air conditioning, which is that it reduces humidity, which can be very much necessary depending on where you live.
I believe the building also had a dehumidifier. Large buildings where this tech is used (currently) have quite complex air handling systems. Switching from a system that cools the air directly (compressors) vs one that uses radiators and cold water does involve some plumbing, but perhaps the air handling unit with the air conditioners can be retrofit with a dehumidifier, so the air is still cycled through that step.
How do you remove heat without creating cold air? I would have liked if the article explained that part a bit more.
I think this statement is getting at two things: you can cool a space without creating cold air (so getting people used to a change in the way cooling is handled) and but also maybe indirectly getting at efficiency.
In a traditional air conditioner you are creating cold air in a central unit. This air is colder than your target temp. This air then circulates and the heat transfer that does the cooling occurs in the air space of the building. The hot air transfers heat to the cold air and maybe if it’s a well designed system displaces the hot air to be returned to the air con.
When your central unit is a water chiller and not an air chiller the initial chilling is more efficient (heat transfer in liquids is more efficient than heat transfer in gas). You also don’t have to cool it as much, because the amount of heat that needs to be removed (transferred from the air to the liquid) is less.
I think I touched on all your questions, but please let me know if you have more or want me to elaborate.
Great answers, thank you! Seems like either way there will be some retrofitting needed in older buildings. You can’t just use the heating system as is and simply switch the warm water out for cold.
This exists elsewhere and has for decades. I’m not trying to take away from what accomplishments are described in the article, only to say there is a lot of info available. The one I am most familiar with is in Toronto, the Deep Lake Water Cooling System.
I worked in an industrial facility that used this style of system (switch from hot water to cold water). It was built in the late 1950s. It wasn’t centralized, but had the same end of loop systems. It used radiators.
There is a fan in the radiator cabinet. I think there is a condensate trap too, but don’t quote me on that.
I believe the building also had a dehumidifier. Large buildings where this tech is used (currently) have quite complex air handling systems. Switching from a system that cools the air directly (compressors) vs one that uses radiators and cold water does involve some plumbing, but perhaps the air handling unit with the air conditioners can be retrofit with a dehumidifier, so the air is still cycled through that step.
I think this statement is getting at two things: you can cool a space without creating cold air (so getting people used to a change in the way cooling is handled) and but also maybe indirectly getting at efficiency.
In a traditional air conditioner you are creating cold air in a central unit. This air is colder than your target temp. This air then circulates and the heat transfer that does the cooling occurs in the air space of the building. The hot air transfers heat to the cold air and maybe if it’s a well designed system displaces the hot air to be returned to the air con.
When your central unit is a water chiller and not an air chiller the initial chilling is more efficient (heat transfer in liquids is more efficient than heat transfer in gas). You also don’t have to cool it as much, because the amount of heat that needs to be removed (transferred from the air to the liquid) is less.
I think I touched on all your questions, but please let me know if you have more or want me to elaborate.
Great answers, thank you! Seems like either way there will be some retrofitting needed in older buildings. You can’t just use the heating system as is and simply switch the warm water out for cold.