Radiant Cooling System
Heat Transfer Mechanism
Combination Of Radiation And Convection
Heat Transfer Medium
Sensible Heat Is Removed By Water & Treated & Cooled Fresh Air Removes Latent Heat.
Equipment Size
As It Removes Sensible Heat Only, And Latent Heat Is Removed By(D.O.A.S) Ventilation Equipment Size Is Reduced, As Cooling Effect Is Radiated Through Floor, Vertical Panels.
Duct Work
Reduced Duct Work By 50-55%.
Maintenance
Lower Maintenance As Less Moving Components.
Operating Cost
Comparatively Lower As Can Work Of Higher Water Temp Of 15 To 18ºc.
Initial Installation Cost
Comparatively Lower.
Concerns
The Limited Experience With Radiant Cooling Creates Concerns About The Quality & Availability Of Professionals For Maintenance & Repair Of The System. Major Facility Mgmt. Teams Do Not Know Much About The Controls And Working Of Its Equipment.
Leakage
Condensation Caused By Humidity & Condensate Leakage Is A Problem, And May Disrupt The WorkFlow. Time Required To Clear The Leakage Is More. Proper Controls Required To Maintain These Major Players Have Specific Software There Are Chances Of Pipes Being Punctured During The Execution.
Zone Control
Zone Control Is Possible, But Slow Response.
Air Drafts
Improves Thermal Comfort Because Heating And Cooling Are Provided Directly & More Evenly To The Occupants without Causing Drafts.
Applications
Suitable Only For Comfort Cooling.
Comfort Control
Best Control As Both Radiant & Air Temp Is Controllers.
Time Lag
There Will Be Around 30 Min Time Lag For Achieving Desired Comfort Levels. Hence The System May Be Required To Be Started Earlier As Compared To Conventional systems.
De-Humidification
Requires Special De-Humidifying Equipment, May Need Separate Chiller, For Low Temp & High Temp Water
False Flooring
This System Cannot Work In Case Of False Flooring. It Requires a Conductive Surface.
Openings In Floor Slab
Minimum Floor Cutouts Required For This System From Plant In Basement.
CFM Required
Very Less CFM Required As The Cooling Is Through Floor. Due To This Smaller Size, Ahus Required In Basement.
Internal Space Required
As The Office Is Cooled Through Floor, Only Displacement Diffusers Are Required Above Floor.
Conventional Air Conditioning Systems
Heat Transfer Mechanism
Convection
Heat Transfer Medium
Conditioned Air Removes Sensible As Well As Latent Heat.
Equipment Size
AHU Size Is More. More Air Needs To Be Circulates.
Duct Work
Cooled Air Is Distributed Through Ducts, Hence Ducting Is More
Maintenance
Higher Maintenance As More Moving Components
Operating Cost
Higher As Chilled Water Required At 7ºc
Initial Installation Cost
Comparatively Higher.
Concerns
Ample Expertise Available As Conventional System, Comfort Temp Include Radiant Portion. Which Are Not Addressed.
Leakage
Leakage Even If Occurred Will Be Mostly In-Service Areas, Time Required To Repair These Leakages Is Less; If accessible.
Zone Control
Simple And Effective Zone Control Can Be Provided.
Air Drafts
Drafts Through Air Distribution System Exist But Can Be Minimized With Good Design.
Applications
Can Be Used In Wide Spread Climatic Conditions.
Comfort Control
Air Flow Is From Top Hence Radiant Loads Are Not Directly Addressed.
Time Lag
There Will Be Around 15 Min Time Lag For Achieving Desired Comfort Levels.
De-Humidification
It Is Achieved At Cooling Coils Itself. At Most Of The Times.
False Flooring
False Flooring Can Be Planned.
Openings In Floor Slab
More Number Of Cutouts Required For This System.
CFM Required
High Cfm Requirement. Bigger Size And More Nos. Of Ahu Required In Basement
Internal Space Required
As The Cooling Has To Be Done Through Ducts And Nozzles, There Will Be Ducts Required To Be Cladded On Almost Alternate Columns.
For More Post Related to HVAC
- Chiller Energy Conservation Guidelines
- Chiller Energy Performance Parameters
- HVAC INTERVIEW QUESTIONS FOR PIPING & FITTINGS
- HVAC INTERVIEW QUESTIONS FOR AHU
- HVAC INTERVIEW QUESTIONS FOR DUCTING