© Copyright CalCERTS, Inc. 2019
Below is an example of modeling mini/multi splits for E+A+A.
1 mini-split with 1 outdoor unit and 1 "ducted" indoor unit -AND-
1 multi-split with 1 outdoor unit and 2 "ducted" indoor units.
The CF1R should reflect 3 systems, not just one.
- Model 3 ducted split systems. You can name them as you wish, but here is a naming example using 1, 2+Indoor #1, and 2+Indoor #2.
- System 1 will consist of 1 outdoor and 1 ducted indoor unit. Because there is only 1 indoor unit, there is nothing different needed – just model it as a stand-alone split system. Use the installed SEER/EER/HSPF efficiencies, but if possible use minimums of 14 SEER/11.7 EER/8.2 HSPF to avoid the MCH-26 Rated equipment verification. (Table 4-3 & 4-6 of 2016 RCM)
- System 2+Indoor #1 will cover the 2nd outdoor unit and 1 ducted indoor unit. Again, model it as a split system the same as System 1 but use the installed SEER/EER/HSPF efficiencies, but if possible use minimums of 14 SEER/11.7 EER/8.2 HSPF to avoid the MCH-26 Rated equipment verification.
- System 2+Indoor #2 is needed to report the 2nd indoor unit of System 2. Again, model as a split system. This method of modeling is only done for E+A+A projects so that the HERS registry will recognize and generate an additional duct verification. New construction projects are modeled in a different manner.
- NOTE: System 2+Indoor #2 will require a special request to CalCERTS support to have IT remove all other verification's other than duct leakage verification.
- For duct leakage verification of a multi-split system with one outdoor unit and 2 or more indoor units, the “measured airflow” method must be used—the cooling method or heating method cannot be used. This requires the airflow CFM of each of the ducted systems to be measured, such as with a flow hood, and then the measured CFM result is multiplied times the 5% allowed leakage rate to determine the duct leakage target the must not be exceeded.
- For airflow and fan efficacy, claim the exemption on the CF2R-MCH-01 form for mini-/multi-split systems that cannot use RA3.3 protocols.
- The CF1R-PRF will include refrigerant charge in climate zones 2, 8-15.
- If the HVAC equipment efficiencies are modeled higher than the minimums, then a MCH-26 form will trigger which requires an AHRI certified product verification.