3.7.5.6 Radiant Cooling

90.1-2016 BM

This section describes a floor-based radiant cooling system and the inputs required.

 

Hydronic Tubing Length

Applicability

Floor-based radiant cooling systems

Definition

The length of the hydronic tubing in the slab

Units

ft

Input Restrictions

As designed

Baseline building

Not applicable

 

Hydronic Tubing Inside Diameter

Applicability

Floor-based radiant cooling systems

Definition

The inside diameter of the hydronic tubing in the slab

Units

ft

Input Restrictions

As designed, between a minimum of ½” and a maximum of ¾”

Baseline building

Not applicable

 

Temperature Control Type

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB

Units

None

Input Restrictions

Fixed at Mean Air Temperature for calculations

Baseline building

Not applicable

 

Rated Flow Rate

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB

Units

None

Input Restrictions

Fixed at Mean Air Temperature for calculations

Baseline building

Not applicable

 

Cooling Control Temperature

Applicability

Variable Flow Systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB

Units

None

Input Restrictions

Fixed at Mean Air Temperature for calculations

Baseline building

Not applicable

 

Condensation Control Type

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB

Units

None

Input Restrictions

Fixed at Mean Air Temperature for calculations

Baseline building

Not applicable

 

Condensation Control Dewpoint Offset

Applicability

Floor-based radiant cooling systems

Definition

The temperature difference above dewpoint that is the minimum cold water supply temperature

Units

None

Input Restrictions

Fixed at 2°F above dewpoint

Baseline building

Not applicable

 

Rated Pump Power Consumption

Applicability

Floor-based radiant cooling systems

Definition

The rated pump power at design conditions

Units

Watts

Input Restrictions

As Designed

Baseline building

Not applicable

 

Motor Efficiency

Applicability

Floor-based radiant cooling systems

Definition

The pump motor efficiency

Units

Decimal fraction

Input Restrictions

As Designed

Baseline building

Default motor efficiency from Standard 90.1-2010 Table 10.8 (Table numbering may change) based on motor nameplate hp

 

Fraction of Motor Heat to Fluid

Applicability

Floor-based radiant cooling systems

Definition

Fraction of the heat from the motor inefficiencies that enters the fluid stream

Units

none

Input Restrictions

As designed. Default is 0.

Baseline building

Not applicable

 

Cooling High Water Temperature

Applicability

Floor-based radiant cooling systems

Definition

The high temperature used for control. If the water temperature is above the high temperature, the control temperature is set to the low control temperature.

Units

°F

Input Restrictions

As designed

Baseline building

Not applicable

 

Cooling Low Water Temperature

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control of the water temperature.  If the water temperature of the radiant cooling is below this temperature, cooling is disabled.

Units

°F

Input Restrictions

Fixed at 55°F

Baseline building

Not applicable

 

Condensation Control Type

Applicability

Floor-based radiant cooling systems

Definition

The simulation program may have a means of detecting when condensation is likely to occur on floor surfaces in the space.  When this occurs, the simulation can shut off the system to prevent condensation from occurring.

Units

List:  None, Simple, Variable

Input Restrictions

As designed

Baseline building

Not applicable

90.1-2019

This section describes a floor-based radiant cooling system and the inputs required for Standard 90.1-2019 evaluation.

 

Hydronic Tubing Length

Applicability

Floor-based radiant cooling systems

Definition

The length of the hydronic tubing in the slab

Units

ft

Input Restrictions

As designed

Baseline Building

Not applicable

 

Hydronic Tubing Inside Diameter

Applicability

Floor-based radiant cooling systems

Definition

The inside diameter of the hydronic tubing in the slab

Units

ft

Input Restrictions

As designed, between a minimum of 1/2 in. and a maximum of 3/4 in.

Baseline Building

Not applicable

 

Temperature Control Type

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, TODB, TOWB)

Units

None

Input Restrictions

Fixed at mean air temperature for calculations

Baseline Building

Not applicable

 

Rated Flow Rate

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB)

Units

None

Input Restrictions

Fixed at mean air temperature for calculations

Baseline Building

Not applicable

 

Cooling Control Temperature

Applicability

Variable flow systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB)

Units

None

Input Restrictions

Fixed at mean air temperature for calculations

Baseline Building

Not applicable

 

Condensation Control Type

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB)

Units

None

Input Restrictions

Fixed at mean air temperature for calculations

Baseline Building

Not applicable

 

Condensation Control Dewpoint Offset

Applicability

Floor-based radiant cooling systems

Definition

The temperature difference above dewpoint that is the minimum cold water supply temperature

Units

None

Input Restrictions

Fixed at 2°F above dewpoint

Baseline Building

Not applicable

 

Rated Pump Power Consumption

Applicability

Floor-based radiant cooling systems

Definition

The rated pump power at design conditions

Units

Watts

Input Restrictions

As designed

Baseline Building

Not applicable

 

Motor Efficiency

Applicability

Floor-based radiant cooling systems

Definition

The pump motor efficiency

Units

Decimal fraction

Input Restrictions

As designed

Baseline Building

Default motor efficiency from Standard 90.1-2019, Table G3.9.1 based on motor nameplate hp

 

Fraction of Motor Heat to Fluid

Applicability

Floor-based radiant cooling systems

Definition

Fraction of the heat from the motor inefficiencies that enters the fluid stream

Units

None

Input Restrictions

As designed. Default is 0.

Baseline Building

Not applicable

 

Cooling High Water Temperature

Applicability

Floor-based radiant cooling systems

Definition

The high temperature used for control. If the water temperature is above the high temperature, the control temperature is set to the low control temperature.

Units

°F

Input Restrictions

As designed

Baseline Building

Not applicable

 

Cooling Low Water Temperature

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control of the water temperature. If the water temperature of the radiant cooling is below this temperature, cooling is disabled.

Units

°F

Input Restrictions

Fixed at 55°F

Baseline Building

Not applicable

 

Condensation of Control Type

Applicability

Floor-based radiant cooling systems

Definition

The simulation program may have a means of detecting when condensation is likely to occur on floor surfaces in the space. When this occurs, the simulation can shut off the system to prevent condensation from occurring.

Units

List: None, Simple, Variable

Input Restrictions

As designed

Baseline Building

Not applicable

90.1-2022

This section describes a floor-based radiant cooling system and the inputs required for Standard 90.1-2022 evaluation.

 

Hydronic Tubing Length

Applicability

Floor-based radiant cooling systems

Definition

The length of the hydronic tubing in the slab

Units

ft

Input Restrictions

As designed

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as the proposed design.

 

Hydronic Tubing Inside Diameter

Applicability

Floor-based radiant cooling systems

Definition

The inside diameter of the hydronic tubing in the slab

Units

ft

Input Restrictions

As designed, between a minimum of 1/2 in. and a maximum of 3/4 in.

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as the proposed design.

 

Temperature Control Type

Applicability

Floor-based radiant cooling systems

Definition

Can be “constant”, “outside air-based reset” or “demand-based reset”

Units

None

Input Restrictions

None

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as the proposed design.

 

Rated Flow Rate

Applicability

Floor-based radiant cooling systems

Definition

The rated GPM flow rate of the system.

Units

GPM

Input Restrictions

None

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

The GPM for the baseline design shall be sized proportionally to the capacities in the proposed design based on sizing runs.

 

Cooling Control Temperature

Applicability

Variable flow systems

Definition

The temperature used for control (operative temperature, mean air temperature, mean radiant temperature, ODB, OWB)

Units

None

Input Restrictions

None

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as the proposed design.

 

 

Condensation Control Dewpoint Offset

Applicability

Floor-based radiant cooling systems

Definition

The temperature difference above dewpoint that is the minimum cold water supply temperature

Units

None

Input Restrictions

As design. Default: Fixed at 2°F above dewpoint

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as proposed.  

 

Rated Pump Power Consumption

Applicability

Floor-based radiant cooling systems

Definition

The rated pump power at design conditions

Units

Watts

Input Restrictions

As designed

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

For pumps included in the scope of the retrofit, as designed except with a motor efficiency minimally compliant with Standard 90.1-2022 Section 10.4.1 based on motor nameplate hp.

Pumps not included in the scope of the alteration should be modeled the same in the baseline and proposed.

 

Motor Efficiency

Applicability

Floor-based radiant cooling systems

Definition

The pump motor efficiency

Units

Decimal fraction

Input Restrictions

As designed

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

For pump motors included in the scope of the retrofit, motor efficiency minimally compliant with Standard 90.1-2022 Section 10.4.1. based on motor nameplate hp.

Pumps not included in the scope of the alteration should be modeled the same in the baseline and proposed.

 

Fraction of Motor Heat to Fluid

Applicability

Floor-based radiant cooling systems

Definition

Fraction of the heat from the motor inefficiencies that enters the fluid stream

Units

None

Input Restrictions

As designed. Default is 0.

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as proposed. Default is 0.

 

Cooling High Water Temperature

Applicability

Floor-based radiant cooling systems

Definition

The high temperature used for control. If the water temperature is above the high temperature, the control temperature is set to the low control temperature.

Units

°F

Input Restrictions

As designed

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as proposed.  

 

Cooling Low Water Temperature

Applicability

Floor-based radiant cooling systems

Definition

The temperature used for control of the water temperature. If the water temperature of the radiant cooling is below this temperature, cooling is disabled.

Units

°F

Input Restrictions

As designed. Default: Fixed at 55°F

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as proposed.  

 

Condensation of Control Type

Applicability

Floor-based radiant cooling systems

Definition

The simulation program may have a means of detecting when condensation is likely to occur on floor surfaces in the space. When this occurs, the simulation can shut off the system to prevent condensation from occurring.

Units

List: None, Simple, Variable

Input Restrictions

As designed

Baseline Building

G3.2 New Construction/Major Alterations

Not applicable

G3.3 Minor Alterations

Same as proposed.