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ANSI/ASHRAE/IES Standard 90.1-2022 Changes

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ANSI/ASHRAE/IES Standard 90.1-2022 Changes
Standard 90.1-2019 Addendum Change
af Modifies lighting modeling requirements in Appendix G with more specific guidance on determining lighting power in the baseline vs. proposed building. 
bc Requires condensing boilers for new construction to achieve condensing-level efficiency (i.e., 90% Et) for large boiler systems (i.e., between 1 and 10 million Btuh) and, to ensure condensing occurs, requires boiler entering water to be in the prescribed limits for temperature or flow rate. 
cd Establishes a minimum enthalpy recovery ratio for energy recovery systems and specifies how bypass or control of the energy recovery system must operate to ensure proper economizer performance.
db Clarifies how to establish the Normative Appendix G baseline space conditioning categories that must be used in conjunction with Tables G3.4-1 through G3.4-8 so that the baseline envelope will remain consistent should Section 3 undergo changes. 
by Adds a minimum prescriptive requirement for on-site renewable energy.
ck Explains Section 12 modeling requirements for proposed designs that utilize a trade-off for the renewable energy requirements in Section 10.5.1. 
cp Explains Appendix G modeling requirements for proposed designs that utilize a trade-off for the renewable energy requirements in Section 10.5.1.
a Establishes minimum fan efficacy requirements for low-power ventilation fans and references Standard 62.2 for determining the minimum ventilation rates for nontransient dwelling units.
b Revises demand control ventilation parameters to be based on climate zone and Standard 62.1 airflow requirements.
c Requires residential HVAC systems greater than 2.1 kW to be equipped with start/stop and setback controls. 
d Adds new term to define parking garage section so that fan requirements can be refined for different configurations. Requires fans with the ability to modulate airflow and power as specified.
f Clarifies the efficiency improvement required in order to eliminate an economizer.
g Adds more specific language about relieving excess outdoor air during air economizer operation through the use of fans or dampers.
h Clarifies that the gross floor area should be used when calculating the area-weighted building performance factor (BPF.)
i Reinstates exception to Appendix G exhaust air energy recovery requirements for laboratory HVAC systems.
k Adjusts Section 12 budget building fan requirements to avoid creating a fan power credit for energy recovery.
l Revises Appendix G language describing how to calculate and assign vertical fenestration in the baseline design.
m Clarifies requirements for motorized dampers on vents for elevator shafts and stairwells; adds exception to allow nonmotorized dampers in mild climates and low-rise buildings.
n Adds an exception to Section allowing units to heat the ventilation airstream above 60°F16°Cif exclusively using series energy recovery.
o Reduces the minimum connected load that triggers daylighting responsive control requirements for sidelighting and toplighting.
p Modifies portions of Section 9 pertaining to alterations to ensure that such projects meet all applicable lighting requirements.
q Corrects Table G3.7 to maintain equivalent space type requirements per the established 2004 baseline.
r Clarifies that residential spaces are not required to have optimal start controls.
s Replaces the term solar reflectance index (SRI) with solar reflectance (for walls only) and establishes a minimum solar reflectance requirement for east-, south-, and west-oriented walls in Climate Zone 0.
t Adds requirement to perform whole-building air leakage testing and measurement on buildings less than 25,000 ft22300 m2, specifies performance requirements for compliance, references the applicable ASTM standard, and modifies relevant Section 3 terminology.
u Specifies the use of air economizers for budget building systems and clarifies method for determining prescriptive HVAC requirements based on the budget system type and capacity.
v Clarifies the documentation that must be submitted to the rating authority or jurisdiction by projects following Section 12 and Appendix G, including simulation files upon request.
w Indicates that chillers (type and number) shall be modeled in the baseline building design based on the total peak coincident cooling load of the baseline HVAC system using chilled water.
x Updates the cooling efficiency adjustment for centrifugal chillers and the requirements for chillers utilizing freeze-protection. Replaces “fluid” and “water” with “liquid” throughout.
y Modifies the minimum efficiency requirements for air-source heat pumps, updates the related AHRI rating standards, introduces a new metric (COPHR) for units that perform heat recovery during chiller operation.
z Lowers the wattage assigned for track lighting to reflect the predominate use of higher-efficiency LED technology.
aa Corrects the SI fan power values in Appendix G to make them consistent with the rest of the standard.
ab Clarifies the process for selecting baseline HVAC systems when using the Appendix G Performance Rating Method (PRM); includes new acronyms to describe HVAC systems and a new definition for “residential associated HVAC zone.”
ac Updates interior lighting power and minimum control requirements: adds a power exception for the germicidal function in luminaires and sources, removes exceptions for casinos and parking garage daylight transition zone lighting, and provides a definition for the latter item.
ad Reorganizes Section 9, “Lighting,” to better parallel the structure of the other main sections.
ae Updates exceptions and footnotes associated with Section 8.4.4 requirements for the minimum efficiency of low-voltage dry-type transformers in commercial buildings. 
ag Introduces an optional Mechanical System Performance Path that allows HVAC system efficiency trade-offs based on a new metric—total system performance ratio (TSPR)—to ensure that equivalent energy savings are maintained compared to the prescriptive approach.
ah Increases the thermal efficiency required for high-capacity gas-fired service water-heating equipment and provides the U.S. DOE criteria for defining high-capacity water heaters.
aj Updates Appendix G to align with Addendum ae clarifications related to baseline transformer performance.
ak Provides criteria for determining when an HVAC zone should be isolated from a multizone system in the baseline building model.
am Modifies exterior lighting power and control requirements based on improvements in technology and revised lighting practices; restructures portions of Section 9 to better communicate exceptions to those requirements.
an Clarifies baseline HVAC fan schedule requirements for projects that rely on ventilation via operable windows that are manually opened by the occupants.
ao Revises the requirements for air curtain units and controls and indicates that installation is to be performed in accordance with the manufacturer’s instructions.
ap Introduces a new section to Standard 90.1 for the use of energy credits to enable an approximately 4% to 5% energy cost savings. There are a total of 33 individual measures from which users can earn the required number of credits for their building type and climate zone. 
aq Introduces requirements for service water heating pipe insulation based on typical operating conditions.
ar Adds requirements for indoor horticultural lighting based on a new metric, photosynthetic photon efficacy (PPE), developed in ANSI/ASABE S640. 
as Rearranges envelope inspection requirements and improves commissioning language throughout. 
at Establishes a consistent numbering system for each section of the standard and revises the definition for alteration.
au Requires that heating and cooling equipment under the simplified compliance approach meet the requirements of Section 
av Adds requirements to address the impacts of thermal bridges in the building envelope.
aw Adds the minimum energy efficiency requirements (and new CFEI metric) for large-diameter ceiling fans from 10 CFR 430.
ay Modifies Tables 6.8.1-8 and 6.8.1-9 for variable refrigerant flow (VRF) equipment based on the new AHRI 1230-2021 test procedure which required an adjustment to EER and IEER values.
az Introduces compressed air system requirements with measures for reducing common sources of energy waste.
bb Updates the lighting power density values for the Building Area Method compliance path based on manufacturer-reported improvements in lighting performance.
bd Provides performance curves for modeling chillers in budget (Section 12) and baseline designs (Appendix G) as well as default performance curves that can be used for chillers in proposed designs.
be Updates references to the latest ANSI/ASHRAE Standard 140-2020 and specifies which simulation program tests are required for compliance with Appendix C and G of Standard 90.1.
bf Updates the decorative and retail lighting power allowances, adds an additional allowance for videoconferencing, and moves the additional power allowances and required controls to a table for easy reference.
bg Updates Sections 8, 9, 10, 12 and Appendix G to reflect the new purpose and scope (Addendum cb), utilizing the new definition of site.
bh Revises the default PV system in the budget building design so that the temperature coefficient of power is aligned with the PV Watts input for a 19% panel efficiency as required by Addendum ck.
bi Creates specific provisions to distinguish roof replacements from other types of alterations.
bj Reformats and clarifies Normative Appendix A requirements for thermal performance calculations to demonstrate compliance with Section 5.5
bk Updates humidity control requirements in accordance with the latest Standard 62.1-2019.
bm Modifies occupied-standby controls from multiple-zone systems to explicitly require an outdoor air reset when ventilation is reduced to zero.
bp Removes the exception for captive card key controls in hotel guestrooms
bq Adds a requirement to perform electrical energy monitoring with separate metering for refrigeration systems where refrigeration accounts for 10% or more of the building load.
br Increases the efficacy threshold for lamps and luminaires in dwelling units and specifies requirements for interior and exterior lighting controls.
bs Updates the lighting power allowances (LPA) in the Simplified Building Method Compliance Path to maintain alignment with the established method (0.9x the Building Area Method LPA values.). Removes an exception for alterations that had incentivized the use of LEDs before they became commonplace.
bt Indicates that baseline system pumps are to be modeled based on the presence of a load and preheat coil temperature is to be modeled compared to the zone with the highest set point. 
bv Updates the building performance factors (BPFs) used to determine compliance with Normative Appendix G based on energy-efficiency improvements in the 2022 standard.
bw Clarifies that the fan efficiency metric is to be applied at the highest design airflow rate.
bx Modifies Table 6.8.1-5 for warm air furnace efficiency requirements to more accurately distinguish between different products and test procedures based on locations in which they are used and their status as DOE or non-DOE covered products.
bz Adds language to specify the sensible energy recovery ratio requirement for systems that require only sensible heating energy recovery.
cb Revises the 90.1 Purpose and Scope to apply to areas outside of the physical building that qualify under the new definition for “site.”
ce Adds new reference and requirements for steel-framed walls aligned with ANSI/AISI S250, which provides additional options for wall framing and insulation placement.
cf Introduces provisions that improve elevator fan, lighting, and movement efficiency.
cg Adds a definition for insulated metal panels (IMPs) and a new section to explain how the U-factor of a given IMP is determined.
ci Requires fan cooling-units outside of the building to have an economizer at the indicated capacity range. 
cj Corrects numerical errors that were present in the centrifugal chiller category when it was updated in Addendum y.
cm Updates the normative references used in the standard to the latest applicable versions.
co Adds new performance requirements for alterations, allowing larger retrofit projects a 5% increase in Building Performance Factor (BPF) relative to new construction vs. smaller retrofit projects which are subject to a new Section G3.3.
cq Modifies Appendix G to align with Section 6 updates (e.g., removes outdated references, corrects instructions for determining equipment efficiency, converts “water” to “liquid” in the descriptions for chiller equipment.)
cr Adds language to limit the extent that envelope trade-offs can be used for compliance with Section 12 and Appendix G based on the amount that a proposed envelope performance factor is permitted to exceed the base value (i.e., envelope “backstop”).
cs Clarifies efficiency requirements for HVAC and service water-heating equipment in the Section 12 budget building design.
ct Provides additional details about the envelope modeling requirements for Appendix G baseline buildings.
cu Specifies that the heat source for performing heat recovery, as required for most acute inpatient hospitals, is the return water from a heat-pump chiller.
cy Updates the normative references to include the latest published addenda to 90.4-2019
da Aligns Appendix G requirements for documentation, simulation programs, climactic data, and exceptions with the corresponding portions of Section 12.