3.8.7 Heat Recovery Equipment | COMNET

Heat Recovery Name
Applicability	All heat recovery systems
Definition	A name assigned to a heat recovery system. This would provide a link to the construction documents.
Units	Text, unique
Input Restrictions	As designed
Baseline Rules	No heat recovery systems

Heat Recovery Device Type
Applicability	All heat recovery systems
Definition	The type of heat recovery equipment. Choices include: Double-Bundled Chiller Generator Engine-Driven Chiller Air Conditioning Unit Refrigerated Casework
Units	List (see above)
Input Restrictions	As designed
Baseline Rules	Heat recovery systems are not included in the baseline system.

Heat Recovery Loads
Applicability	All heat recovery systems
Definition	The loads met by the heat recovery system. Choices include: Service water heating Space heating Process heating More than one load may be selected.
Units	List (see above)
Input Restrictions	As designed
Baseline Rules	Not required in the baseline system.

Heat Recovery Name
Applicability	All heat recovery systems
Definition	A name assigned to a heat recovery system. This would provide a link to the construction documents.
Units	Text, unique
Input Restrictions	As designed
Baseline Rules	No heat recovery systems

Heat Recovery Device Type
Applicability	All heat recovery systems
Definition	The type of heat recovery equipment. Choices include: Double-Bundled Chiller Generator Engine-Driven Chiller Air Conditioning Unit Refrigerated Casework
Units	List (see above)
Input Restrictions	As designed
Baseline Rules	The baseline building is modeled with a condenser heat recovery system for service water heating, when all of the following conditions are true: The building operates 24 hours per day. The total installed heat rejection capacity of the water cooled system exceeds 6,000,000 Btu/h. The design service hot water load is greater than 1,000,000 Btu/h. The required heat recovery system for the baseline building, shall have the capacity to provide the smaller of: 60% of the peak heat rejection load at design conditions, or Preheat of the peak service hot water draw to 85°F If the simulation software is not capable of modeling the requirements described, the requirement for providing such a system in the proposed building shall be met as a prescriptive requirement and heat recovery shall not be modeled in the baseline or proposed building designs.

Heat Recovery Loads
Applicability	All heat recovery systems
Definition	The loads met by the heat recovery system. Choices include: Service water heating Space heating Process heating More than one load may be selected.
Units	List (see above)
Input Restrictions	As designed
Baseline Rules	Service water heating when required as described above

Condenser Heat Recovery Effectiveness
Applicability	Systems that use recover heat from a condenser
Definition	The percentage of heat rejection at design conditions from a DX or heat pump unit in cooling mode that is available for space or water heating
Units	Percent (%)
Input Restrictions	As designed. The software must indicate that supporting documentation is required on the output forms if heat recovery is specified.
Baseline Rules	Same as the proposed

Condenser Heat Recovery Use
Applicability	Systems that use heat recovery
Definition	The end use of the heat recovered from a DX or heat pump unit. The choices are: Reheat coils Water heating
Units	List (see above)
Input Restrictions	As designed. The software must indicate that supporting documentation is required on the output forms if heat recovery is specified.
Baseline Rules	Not applicable for most conditions. The end use will be water heating if required for 24-hour facility operation.

Requirements related to exhaust air recovery are documented in Section 3.7.6.6 of this manual.

Heat Recovery Name
Applicability	All heat recovery systems
Definition	A name assigned to a heat recovery system. This would provide a link to the construction documents.
Units	Text, unique
Input Restrictions	As designed
Baseline Building	Same as proposed

Heat Recovery Device Type
Applicability	All heat recovery systems
Definition	The type of heat recovery equipment. Choices include: Double-bundled chiller Single-bundle heat recovery chiller Generator Engine-driven chiller Air conditioning unit Refrigerated casework
Units	List (see above)
Input Restrictions	As designed
Baseline Building	The baseline building is modeled with a condenser heat recovery system for service water heating, when all of the following conditions are true: The building operates 24 hours per day. The total installed heat rejection capacity of the water cooled system exceeds 6,000,000 Btu/h. The design service hot water load is greater than 1,000,000 Btu/h. The required heat recovery system for the baseline building, shall have the capacity to provide the smaller of: 60% of the peak heat rejection load at design conditions, or Preheat of the peak service hot water draw to 85°F If the simulation software is not capable of modeling the requirements described, the requirement for providing such a system in the proposed building shall be met as a prescriptive requirement and heat recovery shall not be modeled in the baseline or proposed building designs.

Heat Recovery Loads
Applicability	All heat recovery systems
Definition	The loads met by the heat recovery system. Choices include: Service water heating Space heating Process heating More than one load may be selected.
Units	List (see above)
Input Restrictions	As designed
Baseline Building	Service water heating when required as described above

Condenser Heat Recovery Effectiveness
Applicability	Systems that use recover heat from a condenser
Definition	The percentage of heat rejection at design conditions from a DX or heat pump unit in cooling mode that is available for space or water heating
Units	Percent (%)
Input Restrictions	As designed. The software must indicate that supporting documentation is required on the output forms if heat recovery is specified.
Baseline Building	Same as proposed

Condenser Heat Recovery Use
Applicability	Systems that use heat recovery
Definition	The end use of the heat recovered from a DX or heat pump unit. The choices are: Reheat coils Water heating
Units	List (see above)
Input Restrictions	As designed. The software must indicate that supporting documentation is required on the output forms if heat recovery is specified.
Baseline Building	Not applicable for most conditions. The end use will be water heating if required for 24-hour facility operation.

Requirements related to exhaust air recovery are documented in Section 3.7.6.6 of this manual.

Heat Recovery Name
Applicability	All heat recovery systems
Definition	A name assigned to a heat recovery system. This would provide a link to the construction documents.
Units	Text, unique
Input Restrictions	As designed
Baseline Building	Same as proposed

Heat Recovery Device Type
Applicability	All heat recovery systems
Definition	The type of heat recovery equipment. Choices include: Double-bundled chiller Single-bundle heat recovery chiller Generator Engine-driven chiller Air conditioning unit Refrigerated casework
Units	List (see above)
Input Restrictions	As designed
Baseline Building	G3.2 New Construction/Major Alterations The baseline building is modeled with a condenser heat recovery system for service water heating, when all of the following conditions are true: The building operates 24 hours per day. The total installed heat rejection capacity of the water-cooled system exceeds 6,000,000 Btu/h. The design service hot water load is greater than 1,000,000 Btu/h. The required heat recovery system for the baseline building, shall have the capacity to provide the smaller of: 60% of the peak heat rejection load at design conditions, or Preheat of the peak service hot water draw to 85°F If the simulation software is not capable of modeling the requirements described the requirement for providing such a system in the proposed building shall be met as a prescriptive requirement and heat recovery shall not be modeled in the baseline or proposed building designs. G3.3 Minor Alterations If Standard 90.1-2022 Sections 6.5.6.2 and/or 6.5.6.3 are applicable based on the scope of the alteration and the language in Standard 90.1-2022 Section 6.1.4 then the baseline shall be modeled with heat recovery according to the requirements in these Standard 90.1-2022 sections which are explained in detail directly below. Requirements of Standard 90.1-2022 Section 6.5.6.2: The baseline building is modeled with a condenser heat recovery system for service water heating, when all of the following conditions are true: The building operates 24 hours per day. The total installed heat rejection capacity of the water-cooled system exceeds 6,000,000 Btu/h. The design service hot water load is greater than 1,000,000 Btu/h. The required heat recovery system for the baseline building, shall have the capacity to provide the smaller of: 60% of the peak heat rejection load at design conditions, or Preheat of the peak service hot water draw to 85°F Exceptions to 90.1 6.5.6.2: Facilities that employ condenser heat recovery for space heating with a heat recovery design exceeding 30% of the peak water-cooled condenser load at design conditions. Facilities that provide 60% of their service water heating from on-site renewable energy or site-recovered energy or from other sources Requirements of Standard 90.1-2022 Section 6.5.6.3: Where heating water is used for space heating, a heat-pump chiller meeting the requirements of Table 6.8.1-16 for heat recovery that uses the cooling system return water as the heat source shall be modeled in the baseline, provided all of the following are true: The building is an acute inpatient hospital, where the building or portion of a building is used on a 24-hour basis for the inpatient medical, obstetric, or surgical care for patients. The total design chilled-water capacity for the acute inpatient hospital, either air cooled or water cooled, required at cooling design conditions exceeds 3,600,000 Btu/h of cooling. Simultaneous heating, including reheat, and cooling occurs above 60°F outdoor air temperature. The modeled heat recovery system shall have a cooling capacity that is at least 7% of the total design chilled-water capacity of the acute inpatient hospital at peak design conditions. Exception to 90.1 6.5.6.3: Buildings in Climate Zones 5C, 6B, 7, and 8. Otherwise, heat recovery devices should be modeled identically in the baseline and proposed.

Heat Recovery Loads
Applicability	All heat recovery systems
Definition	The loads met by the heat recovery system. Choices include: Service water heating Space heating Process heating More than one load may be selected.
Units	List (see above)
Input Restrictions	As designed
Baseline Building	G3.2 New Construction/Major Alterations Service water heating when required as described above. G3.3 Minor Alterations Space heating and/ or service water heating when required as described under the Heat Recovery Device Type descriptor.

Condenser Heat Recovery Effectiveness
Applicability	Systems that use recover heat from a condenser
Definition	The percentage of heat rejection at design conditions from a DX or heat pump unit in cooling mode that is available for space or water heating
Units	Percent (%)
Input Restrictions	As designed. The software must indicate that supporting documentation is required on the output forms if heat recovery is specified.
Baseline Building	Same as proposed. Where no system exists in the proposed but is required to be modeled in the baseline model. There are no restrictions other than modeling the system as minimally compliant with Standard 90.1-2022 Sections 6.5.6.2 and/or 6.5.6.3 as applicable based on the scope of the alteration and the language in Standard 90.1-2022 Section 6.1.4. See the Heat Recovery Device Type descriptor for detailed requirements.

Condenser Heat Recovery Use
Applicability	Systems that use heat recovery
Definition	The end use of the heat recovered from a DX or heat pump unit. The choices are: Reheat coils Water heating
Units	List (see above)
Input Restrictions	As designed. The software must indicate that supporting documentation is required on the output forms if heat recovery is specified.
Baseline Building	G3.2 New Construction/Major Alterations The end use will be water heating if required for 24-hour facility operation. G3.3 Minor Alterations The end use will be service water heating and/or space heating if required.

Heat Recovery Name
Applicability	All heat recovery systems
Definition	A name assigned to a heat recovery system. This would provide a link to the construction documents.
Units	Text, unique
Input Restrictions	As designed

Heat Recovery Device Type
Applicability	All heat recovery systems
Definition	The type of heat recovery equipment. Choices include: Double-Bundled Chiller Generator Engine-Driven Chiller Air Conditioning Unit Refrigerated Casework
Units	List (see above)
Input Restrictions	As designed

Heat Recovery Loads
Applicability	All heat recovery systems
Definition	The loads met by the heat recovery system. Choices include: Service water heating Space heating Process heating More than one load may be selected.
Units	List (see above)
Input Restrictions	As designed

Heat Recovery Name
Applicability	All heat recovery systems
Definition	A name assigned to a heat recovery system. This would provide a link to the construction documents.
Units	Text, unique
Input Restrictions	As designed

Heat Recovery Device Type
Applicability	All heat recovery systems
Definition	The type of heat recovery equipment. Choices include: Double-Bundled Chiller Generator Engine-Driven Chiller Air Conditioning Unit Refrigerated Casework
Units	List (see above)
Input Restrictions	As designed

Heat Recovery Loads
Applicability	All heat recovery systems
Definition	The loads met by the heat recovery system. Choices include: Service water heating Space heating Process heating More than one load may be selected.
Units	List (see above)
Input Restrictions	As designed