ASHRAE Standard 174 provides test methods for rating the performance of desiccant-based dehumidification equipment operating at atmospheric pressure and using desiccants combined with other components to dehumidify air. The 2022 revision of Standard 174 includes updated references.<\/p>\n
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| 3<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 4<\/td>\n | FOREWORD 1. PURPOSE 2. SCOPE 3. DEFINITIONS AND NOMENCLATURE 3.1 Definitions <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | 3.2 Nomenclature <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | 4. CLASSIFICATIONS <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | 5. REQUIREMENTS 5.1 Performance of the Dehumidifier System. The performance of the dehumidifier system is determined for one or more of the operating modes listed in Section 4 (see Table 1). For each mode, the following parameters are determined: 6. MEASUREMENTS 6.1 Instruments. For precision, all instruments used for measurement shall be calibrated by comparison with an instrument that has a NIST (or equivalent national laboratory) certification in the range of use specified, or shall be an instrument that … 6.2 Temperature Measurements. Temperature measurement instruments, unless noted below, shall be in accordance with ASHRAE Standard 41.1, Standard Method for Temperature Measurement 1. <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 6.3 Pressure Measurements. All pressure measuring instruments shall be in accordance with ANSI\/ASHRAE Standard 41.3, Standard Method for Pressure Measurement 2. 6.4 Electrical Measurements 6.5 Liquid Flow Measurement 6.6 Dew-Point Measurements. All dew-point measurements shall be in accordance with ASHRAE Standard 41.6, Standard Method for Measurement of Moist Air Properties 4, Sections 6.3 and 6.4. 6.7 Time Measurements. Time measurements shall be made with instruments having an accuracy of \u00b10.20% of the reading. 6.8 Weight Measurements. Weight measurement shall be made with apparatus having an accuracy of \u00b10.20% of the reading. <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 6.9 Gas Fuel Measurements. Measurement of the gas fuel rate during testing shall be made with a calibrated meter of the constant-volume type. If possible, the heating value for the fuel gas used should be obtained from the gas company supplying the f… 6.10 Airflow Measurements 6.11 Water Properties Measurement. Temperature measuring instruments shall be placed so as to measure accurately the temperature of water entering and leaving the equipment. The water lines shall be insulated at and adjacent to the temperature measur… 6.12 Steam Properties and Steam Condensate Flow Measurement 6.13 Tracer Gas Measurements. All measurements of tracer gas concentrations shall be made with an accuracy of \u00b11%. 7. APPARATUS 7.1 Test Room and Facilities. The test room and facilities shall comply with the provisions for testing with the tunnel air-enthalpy method as defined in ASHRAE 41.2, Standard Methods for Laboratory Airflow Measurement 6. A facility is required with … 7.2 Test Setup. The test setup shall be capable of permitting the test equipment to be treated as a \u201cblack box\u201d\u2014that is, measurements made on the inputs to the equipment and outputs from the equipment can be made to determine its sensible and l… <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 7.3 Test Equipment Installation 7.4 Measurement of Outdoor Air Percentage. Operational Modes 4.1 (Recirculation) and 4.2 (Exhaust) provide no outdoor air inlet airflows. All supply air derives from recirculation air, thus the outdoor air percentage is defined by these modes as 0% o… <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 8. METHODS OF TEST 8.1 Test Methods 8.2 Testing Sequence. For Modes 4.5 and 4.6, the test to determine designated equipment outdoor air percentage shall be conducted prior to the test to determine equipment performance. 9. TEST PROCEDURES 9.1 Basic Approach. Each mode of operation defined by the manufacturer and specified in Section 4 shall be tested independently. The equipment under test and measuring apparatus shall be operated until steady-state conditions have been maintained for… 9.2 Steady-State Operation. Steady-state operation of the equipment under test shall be maintained for the pretest period and the six consecutive ten-minute intervals of the test period to obtain a valid test. Steady-state operation requires airflows… 9.3 Mode 4.5 Procedures. The procedures used for testing the equipment outdoor air percentage of Mode 4.5 operation shall be in accordance with the test procedures of ASHRAE Standard 41.2, Standard Methods for Laboratory Airflow Measurement 6. 9.4 Mode 4.6 Procedures. The procedure used for testing the equipment for outdoor air percentage of Mode 4.6 operation shall be as follows. The equipment shall be set up for equipment performance testing of Mode 4.6, including the tracer gas testing … <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 10. DATA TO BE RECORDED 10.1 Test Data. The data listed in Table 2 shall be recorded as appropriate to document the results of the tests conducted in accordance with Sections 6 through 9 of this standard. Specific recorded data will be dependent on actual equipment configur… 11. CALCULATIONS 11.1 Standard Airflow Rate Values. The standard airflow rates for the discharge, indoor return inlet, supply, outdoor air inlet, separate air (if used), and hot air shall be determined from the following equations (I-P equations are followed by SI eq… 11.2 Enthalpy Values. Enthalpy (Btu\/lb of dry air) (kJ\/kg of dry air) shall be determined for airflows used by the equipment in accordance with procedures presented in 2017 ASHRAE Handbook\u2014Fundamentals 7, Chapter 6, \u201cNumerical Calculation of Mois… <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 11.3 Dehumidifier System Capacities <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 11.4 Equipment Energy Use. Equipment energy use Q shall be defined as the sum of all the energy input flows to the equipment over the test interval except for any energy added or removed by a separated airflow if used. This shall be stated in terms o… <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 11.5 Energy Balance and Test Validation 12. NORMATIVE REFERENCES <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | INFORMATIVE APPENDIX A: STANDARD RATING CONDITIONS A1. Entering Air Temperature and Humidity A2. Outdoor Air Percentage A3. Supply Air External Resistance A4. Test Set-Up Examples <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | A4.1 Dehumidifier Equipment Designed for Indoor Installation (Nonweatherized) A4.2 Dehumidifier Equipment Designed for Outdoor Installation (Weatherized) A4.3 Equipment Designed for Outdoor Installation (Fuel-Fired and Weatherized). When weatherized equipment is fuel-fired, means are required to vent products of combustion from the outdoor room of the test facility. Figure A-12 also demonstrates venti… A5. Equipment Performance A5.1 Coefficient of Performance, Total. The coefficient of performance total (COPT) for the equipment under test shall be defined as follows: <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | A5.2 Coefficient of Performance, Sensible. The coefficient of performance sensible (COPS) for the equipment under test shall be defined follows: A5.3 Coefficient of Performance, Latent. The coefficient of performance latent (COPL) for the equipment under test shall be defined follows: A5.4 Energy Efficiency Ratio, Total. The performance energy efficiency ratio total (EERT) for the equipment under test shall be defined follows: A5.5 Energy Efficiency Ratio, Sensible. The performance energy efficiency ratio sensible (EERS) for the equipment under test shall be defined follows: A5.6 Energy Efficiency Ratio, Latent. The performance energy efficiency ratio latent (EERL) for the equipment under test shall be defined as follows: A6. Sample Calculation of Moisture Added to AIRSTREAM by Direct-Fired Gas Burner <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" ASHRAE Standard 174-2022 — Method of Test for Rating Desiccant-Based Dehumidification Equipment (ANSI Approved)<\/b><\/p>\n |