3.7.6.1 General

Heating Source
Applicability	All systems that provide heating
Definition	The source of heating for the heating and preheat coils. The choices are: Hot water Steam Electric resistance Electric heat pump Gas furnace Gas heat pump (optional feature) Oil furnace Heat recovery (for preheat coils in proposed designs)
Units	List (see above)
Input Restrictions	As designed
Baseline Rules	Based on the prescribed system type. See Table 3.1.2-3

90.1-2019

Heating Source

Applicability

All systems that provide heating

Definition

The source of heating for the heating and preheat coils. The choices are:

Units

List (see above)

Input Restrictions

As designed

Baseline Building

Based on the prescribed system type

Table 73. Heating Source for Baseline Building

Baseline Building System	Heating Type
1 – PTAC	Hot water fossil fuel boiler
2 – PTHP	Electric heat pump
3 – PSZ AC	Fossil fuel furnace
4 – PSZ HP	Electric heat pump
5 – PVAV reheat	Hot water fossil fuel boiler
6 – Packaged VAV with PFP Boxes	Electric resistance
7 – VAV with Reheat	Hot water fossil fuel boiler
8 – VAV with PFP Boxes	Electric resistance
9– Heating and Ventilation	Fossil fuel furnace
10 – Heating and Ventilation	Electric Resistance
11- Single Zone VAV	For climate zones 0-3A, the heating system will be electric resistance. All other will be hot-water fossil fuel boilers.
12- Single Zone CAV HW	Hot water fossil fuel boiler
13- Single Zone CAV ER	Electric resistance

Total Heating Coil Capacity
Applicability	All systems with heating coils
Definition	The heating capacity of a heating coil at ARI conditions
Units	Btu/h
Input Restrictions	As designed. The capacity would need to be adjusted if the number of UMLH exceeds 300.
Baseline Building	Autosize with a heating oversizing factor of 25%. Sizing calculations shall be based on the heating design day and cooling design day conditions, as defined in Section 3.2.3 of this document. Oversizing would be carried out at zone level where the sizing parameters would be applied to the zone design heating loads, but not the airflow rates. Refer to Section 2.7.2 of this document for more details.

Number of Heating Stages
Applicability	Heating systems with multiple stages
Definition	The number of heating stages provided by the system. Multiple stages could be provided via a heat pump or via a multiple-stage gas furnace.
Units	Integer
Input Restrictions	As designed
Baseline Building	Single stage

Heating Capacity by Stage
Applicability	Heating systems with multiple stages
Definition	Provides the total heating capacity of each heating stage, at ARI rated conditions. The capacity is expressed as an array, with each entry a fraction of the total rated cooling capacity for the unit. For example, if the stage heating capacity is 48,000 Btu/h and the heating capacity is 96,000 Btu/h, the capacity is expressed as “0.5” for that stage.
Units	Array of fractions
Input Restrictions	As designed
Baseline Building	Not applicable