3.7.6.2 Preheat Coil

90.1-2016 BM

The baseline system shall be modeled with a preheat coil controlled to a fixed setpoint 20°F less than the design room heating temperature setpoint.

 

Preheat Coil Capacity

Applicability

Systems with a preheat coil located in the outside air stream

Definition

The heating capacity of a preheating coil at design conditions.

Units

Btu/h

Input Restrictions

As designed

Baseline Rules

For baseline systems 5 through 8, the baseline system shall be modeled with a preheat coil controlled to a fixed setpoint of 20 °F less than the design room heating setpoint. See G3.1.3.19.

 

Preheat Coil Type

Applicability

Systems with a preheat coil located in the outside air stream

Definition

The heating source of a preheating coil. The choices are:

  • electric resistance
  • gas furnace
  • hydronic (supplied by boiler)

Units

List (see above)

Input Restrictions

As designed

Baseline Rules

The heating source for the baseline preheat coil shall be the same as the baseline system. For baseline systems, 5 and 7, the preheat coils will be hydronic. Buildings with baseline system 6 and 8 will be modeled with electric resistance preheat coils.

 

Preheat Coil Efficiency

Applicability

Systems with a gas preheat coil

Definition

The heating efficiency of a preheating coil at design conditions

Units

Unitless

Input Restrictions

As designed, default is 80%

Baseline Rules

Not applicable. Baseline building would have preheat coils only for systems 5-8 which would either be electric resistance or hydronic.