I'm looking for feedback on my recommendations for selecting air-conditioning equipment to maximize the number of credits and points your project can achieve. These are pretty surface l
These ideas are specifically for the AC unit itself and doesn't take into account the entire HVAC system (ducting, terminal boxes, etc.).
I'd love to know if these are reasonable and hear of anyone else experience with Air Conditioners and LEED.
*The scope of the question falls outside the single credit listed as the forum area on my post*
NC-v4 EAc1 Advanced Commissioning:
- Look for equipment with built in monitoring. Monitored variables (such as superheat, subcool, discharge temperature) that are easily accessible or recordable can be included in a commissioning plan to assess HVAC system performance and indicate if maintenance is required.
NC-v4 EAc2/EBOM-v4 EAc4 Optimize Energy Performance:
- Look for equipment with high IEER ratings. Equipment operates most of its lifetime at part loads.
- LOCATION DEPENDENT. For outdoor units, take into consideration cabinet insulation and thermal breaks for improved performance once installed and operational.
- Look for equipment with multi-stage capacity control to reduce energy consumption. Equipment with single stage on/off or hot gas bypass as capacity control methods can consume more energy.
- For comfort cooling, low supply air dew points are not always necessary (below 55F) and would not improve comfort. Cooling to lower dew points when not necessary can increase energy consumption.
- Select equipment with low leakage ratings (tested to AHRI 1350) to indicate high performance and potentially reduce actual energy consumption.
- Look for equipment that reduces pressure drop through the unit. Typically air will be passing through the unit regardless of if it is cooling. Lower pressure drops can translate to smaller fan motor power requirements.
NC-v4 EA6/EBOM-v4 EA8 Enhanced Refrigerant Management:
- If your unit comes with packaged cooling, inquire with the manufacturer about the amount of charge and type of refrigerant used.
- If your unit has a remote condenser, ensure that the installing contractor relays how much refrigerant and the type of refrigerant used.
- With knowledge of the refrigerant charge amount and type, calculate the LCGWP and LCODP of your unit(s) to see if they meet the minimum criteria.
- Look for AC systems that use 0 ODP refrigerant with a GWP of less than 50 (CO2 or Propane as refrigerant).
NC-v4 MRc2 Building Product Disclosure and Optimization - Environmental Product Declarations:
- Select products that have EDP declarations.
NC-v4 EQc4 IAQ Assessment:
- Select equipment with low leakage ratings (tested to AHRI 1350) to mitigate unfiltered outdoor from air infiltrating the system when performing an indoor air quality testing.
- Select appropriate filters for the building/ design spaces application.
NC-v4 EQc5/EBOM-v4 EQc3 Thermal Comfort:
- Select equipment that can achieve one of the two specified thermal comfort options.
EBOM-v4 EQc10 Occupant Comfort Survey
- If the occupant comfort survey reveals that occupants are dissatisfied with:
Acoustics- Consider equipment that emit low sound power
Indoor Air Quality- Consider equipment low leakage rated and proper filters
Thermal Comfort- Consider equipment with multi-stage capacity control
and the existing Air conditioner is deemed as source of discomfort.
NC-v4 EQc9 Acoustic Performance:
- Look for equipment (low sound power) that helps achieve the required STCC for your building/design space.
NC-v4 WEc1,c2/EBOM-v4 WEc1,c2 Indoor/Outdoor Water Use Reduction:
- Look into recycling condensate from your AC unit to reduce on-site indoor/outdoor water usage.
Thanks for any help! This is a very open ended post and I'd love to hear some of your thoughts and start a discussion.