ASHRAE-90.1-2022- - Page 374

Extracted Content

(This is a normative appendix and is part of this standard.)

NORMATIVE APPENDIX L MECHANICAL SYSTEM PERFORMANCE RATING METHOD

L1. GENERAL

L1.1 Scope. This appendix offers an alternative path of compliance for HVAC systems in accordance with Section 6.6.2. This appendix establishes the requirements for HVAC systems that use the Mechanical System Performance Rating Method and requirements for calculating TSPRp and TSPRr to demonstrate compliance in accordance with Section 6.6.2.2. Not all HVAC systems are allowed to use the Mechanical System Performance Rating Method as described in Section L1.1.1.

L1.1.1 Allowable HVAC Systems. HVAC systems are allowed to use the Mechanical System Performance Rating Method if they comply with all the following criteria:

a. The HVAC system type is included in Table L.1.1.1. b. The HVAC system serves a building use type included in Section L1.1.1.1. c. The HVAC system is not excluded by Section L1.1.1.2. d. The HVAC system is powered by grid-delivered electricity, renewable electricity, natural gas, propane,

renewable thermal energy, or distillate fuel oil.

Informative Notes:

1. The intention of the scope is to allow most of the building to use the TSPR path and have portions of the buildings that cannot use the TSPR path use either the prescriptive path or the Computer Room System Path.
2. The allowed system types may not be supported by all simulation program versions. The simula- tion program is required to support the reference systems for the building types modeled, and the proposed system type(s) must be supported by the simulation program .

L1.1.1.1 Allowable Building Use Types. HVAC systems that serve the following building use types are allowed to use the Mechanical System Performance Rating Method:

a. Large office ( gross conditioned floor area >150,000 ft [2] or >5 stories ) b. Medium office ( gross conditioned floor area 5000 to 150,000 ft [2] and ≤5 stories ) c. Small office ( gross conditioned floor area ≤5000 ft [2] and ≤5 stories ) d. Retail e. Multifamily (including dormitory) f. Hotel (including motel) g. School (including education and university) h. Other building use types that are <1000 ft [2] and <10% of the building conditioned floor area unless spe cifically excluded by Section L1.1.1.2(a)

Informative Note: Item (h) allows for a small sandwich or coffee counter service area but not a restaurant in an office building lobby or bookstore, for example.

L1.1.1.2 Excluded HVAC Systems. The following HVAC systems are excluded from using the Mechanical System Performance Rating Method:

a. HVAC systems serving one of the following excluded building areas:

1. Data centers and computer rooms with equipment power density exceeding 20 W/ft [2] of conditioned floor area and exceeding 10 kW of equipment load
2. Laboratories with fume hoods
3. Locker rooms with more than four showers
4. Cafeterias and dining rooms
5. Restaurants and commercial kitchens with total cooking capacity greater than 100,000 Btu/h (does not include break rooms)
6. Natatoriums or rooms with saunas
7. Areas of buildings with commercial refrigeration equipment exceeding 100 kW of power input b. HVAC systems that are not replaced in their entirety as part of an alteration and are not serving initial

build-out construction

372 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)