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Originally Posted by rokim99
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Does radiant cooling considered to be superior technology then conventional , forced air A/C then ? why would developers choose radiant cooling over forced air ?
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Don't consider radiant cooling as A/C.
Use of radiant cooling is limited and often supplemented with another source of cooling because it cannot lower the room temperature effectively.
It will create condensation issues as soon as you try to cool the room like an A/C.
For example, it's 28C with 48% RH today = dew point of ~16C.
You'll start to see condensation on the ceiling once the surface temperature drops below 16C and you left a window open or took a hot shower.
To prevent the condensate water dripping from the ceiling, cooling tubes should not be chilled less than 16C at the source, which is not cold enough to effectively cool the room.
So why use radiant cooling?
At the end of the day, it comes down to the installation cost.
It's way cheaper to lay radiant tubings while pouring slab instead of installing fan coil/air handler and ductworks.
With assumption:
- 1000 sq ft 2BR unit
- PEX (plastic) radiant tubings @ $0.50/ft
- 1500 ft of PEX (more than enough to cover 1000 sq ft)
Ignoring labour, the installation cost would be:
- $1000+/unit for radiant cooling ($750 PEX+$100 t-stat+$150 zone valve)
- $4000+/unit for fan coil with ductwork ($3000 coil+$100 t-stat+$1000 ductwork+additional anchoring/hatch/drywall finish)
- Cost savings would be far greater for smaller sized 1BR units because base costs for fan coils are generally expensive regardless of capacity.
Now, the benefit of radiant cooling would be:
- Flexibility and saves a lot of space inside the residential unit
- Virtually no maintenance requirements for occupants with no filters or moving parts
- It's quiet and "gentle" because it does not move air
Again, radiant cooling will not lower your room temperature much but makes you "feel" cooler, like lying on a tiled floor instead of carpet.
Most buildings needing A/C prefer to cool and dehumidify the air, so they use more expensive fan coils with chilled water running through and condensate pan will catch moisture as air passes through.
I think its an added bonus to have at least radiant cooling, but it is not like an A/C without fan coils inside each residential units.