ASHRAE-90.1-2022- - Page 075
Extracted Content
c. Cooling (if any) shall be provided by a unitary packaged or split- system air conditioner that is either air
cooled or evaporatively cooled, with efficiency meeting the requirements shown in Table 6.8.1-1 (air conditioners), Table 6.8.1-2 (heat pumps), or Table 6.8.1-4 (packaged terminal and room air condition- ers and heat pumps) for the applicable equipment category. Cooling equipment shall also comply with Section 6.4.1.4. d. The system shall have an air economizer meeting the requirements of Sections 6.5.1 and 6.4.3.12. e. Heating (if any) shall be provided by a unitary packaged or split- system heat pump that meets the appli cable efficiency requirements shown in Table 6.8.1-2 (heat pumps) or Table 6.8.1-4 (packaged terminal and room air conditioners and heat pumps), a fuel -fired furnace that meets the applicable efficiency requirements shown in Table 6.8.1-5 (furnaces, duct furnaces, and unit heaters), an electric resistance heater, or a baseboard system connected to a boiler that meets the applicable efficiency requirements shown in Table 6.8.1-6 ( boilers ). Heating equipment shall also comply with Section 6.4.1.4. f. The system shall meet the exhaust air energy recovery requirements of Section 6.5.6.1. g. The system shall be controlled by a manual changeover or dual set-point thermostat . h. If a heat pump equipped with auxiliary internal electric resistance heaters is installed, controls shall be
provided that prevent supplemental heater operation when the heating load can be met by the heat pump alone during both steady-state operation and setback recovery. Supplemental heater operation is permitted during outdoor coil defrost cycles. The heat pump must be controlled by either (1) a digital or electronic thermostat designed for heat pump use that energizes auxiliary heat only when the heat pump has insufficient capacity to maintain set point or to warm up the space at a sufficient rate or (2) a multistage space thermostat and an outdoor air thermostat wired to energize auxiliary heat only on the last stage of the space thermostat and when outdoor air temperature is less than 40°F. Exceptions to 6.3.2.(h): Heat pumps that comply with the following:
- Have a minimum efficiency regulated by NAECA.
- Meet the requirements in Table 6.8.1-2.
- Include all usage of internal electric resistance heating. i. The system controls shall not permit reheat or any other form of simultaneous heating and cooling for humidity control. Exception to 6.3.2(i): Humidity control assisted by hot-gas reheat or heat from 100% site-recovered
energy is permitted. j. Systems serving spaces other than residential spaces, that do not require continuous operation, with a cooling or heating capacity greater than 7000 Btu/h shall comply with Sections 6.4.3.3.1 and 6.4.3.3.2. k. Systems serving residential spaces other than hotel/motel guest rooms shall comply with Sections
6.4.3.3.1 and 6.4.3.3.2 except for electric resistance heaters rated at 2 hp or less with a readily accessible manual control that lowers the set point or turns the unit off. l. Systems serving hotel/motel guest rooms shall comply with Section 6.4.3.3.5. m. Except for piping within manufacturers ’ units, HVAC piping shall be insulated in accordance with
Tables 6.8.3-1 and 6.8.3-2. Insulation exposed to weather shall be suitable for outdoor service, e.g., protected by aluminum, sheet metal, painted canvas, or plastic cover. Cellular foam insulation shall be protected as above or painted with a coating that is water retardant and provides shielding from solar radiation. n. Ductwork and plenums shall be insulated in accordance with Table 6.8.2 and shall be sealed in accor dance with Section 6.4.4.2.1. o. Construction documents shall require a ducted system to be air balanced in accordance with industry
accepted procedures. p. Outdoor air intake and exhaust systems shall meet the requirements of Section 6.4.3.4. q. Where separate heating and cooling equipment serves the same temperature zone, thermostats shall be
interlocked to prevent simultaneous heating and cooling. r. Systems with a design supply air capacity greater than 10,000 cfm shall have optimum start controls . s. The system shall comply with the demand control ventilation requirements in Section 6.4.3.8, occupiedstandby controls in Section 6.5.3.9, and the ventilation design requirements in Section 6.5.3.8. t. The system complies with the door switch requirements in Section 6.5.10.
6.4 Mandatory Provisions 6.4.1 Equipment Efficiencies, Verification, and Labeling Requirements 6.4.1.1 Minimum Equipment Efficiencies—Listed Equipment—Standard Rating and Operating Conditions. Equipment shown in Tables 6.8.1-1 through 6.8.1-21 shall have a minimum performance at the specified rating conditions when tested in accordance with the specified test procedure. Where multiple rating
ANSI/ASHRAE/IES Standard 90.1-2022 (I-P) 73