1. United Technologies Sr. Fellow
Policy Programs for Improving Energy Efficiency in Existing Cooling and Heat Pump Systems Session VI, July 10, 2018
Richard Lord
United Technologies Sr. Fellow
ASHRAE Fellow
ASHRAE 90.1 Vice Chair

2. Introduction
The focus of my comments are relative to policies and initiatives in the USA and North America with a focus on commercial buildings
Overall the Energy Efficiency initiatives in the USA are very mature and have been in place since the 1970’s but continue to evolve, but for global products are becoming very complex and resource intensive.
The approach and policies have matured and use a multi-tiered efficiency approach;
Minimum prescriptive efficiencies defined by US Department of Energy (DOE), ASHRAE 90.1, and IECC
Higher Tier Standards supported by, EnergyStar, CEE, Guidelines and Utility Rebates (3-4 levels)
Full Systems Approaches supported by new ASHRAE Appendix G, USGBC and Green Building Standards
Historical approach of focusing on full load component based efficiencies is reaching the technical limits (“Max Tech”) and there are new initiatives begin to be considered and used;
Annualized metrics (IPLV, GPLV, IEER, etc.)
Sub-systems, and systems approaches
Life cycle sustained approaches using continuous commissioning and diagnostics
Some may think that the equipment efficiencies only applies to new products, but regulations and standards in the US apply in most cases to replacement and major renovations .

3. US Regulatory Environment (Standards and Guidelines)
USA Efficiency Regulations
Most of these are support be test based certification program
Light Commercial
(<65K, Single Phase)
Commercial
(≥65K, 3 Phase)
Minimum Efficiency ASHRAE 90.1
Higher Tier Requirements
Minimum Efficiency
Higher Tier Requirements
CEE
Federal Regulations
NAECA/ESIA (DOE)
Non Federal Requirements
Federal Regulations
EPACT/ESIA (DOE)
Non Federal Requirements
EnergyStar (EPA)
DOE Standards and Test Procedures
EnergyStar (EPA)
ASHRAE 90.1 Requirements
ASHRAE 90.1, 90.4
IECC
State Codes (Title 20,24)
City Codes
ASHRAE 189.1, 2, 4
CEE
FEMP (DOE)
IRC Standard
AC Rooftops <760K
WC Packaged <760K
AC Cond Units <240K
WSHP
VRF <300K
Motors
Gas Furnace
Fans
CALGREEN
ASHRAE 189.1/IGCC
Large Packaged>760
All Chillers
Large Condensing Units
Fan Coils
Air Handlers
Export Products
State Codes
(i.e. Title 20)
LEED
CALGREEN
LEED
Whole Home
Requirements not federally preempted
controlled and subject to change at the discretion of the author
Federally Controlled Requirements
Preempt state and local codes
ASHRAE Advanced Design Guide
ASHRAE Building Labeling (BEQ)
The higher tier marketing is about 20% of the market, but varies regional and is highly influenced by utility and state incentive/rebate programs
EnergyStar Benchmark

4. Historical Regulatory Improvements – Commercial Buildings
Chart is based on data from the DOE/PNNL Progress Studies, ASHRAE 90.1 Strategic Plan, and ASHRAE BOD goals, and of ASHRAE 90.1 and Equipment Efficiency Historical Improvements

5. Understanding Efficiency Metrics
Industry historically focused on full load metrics at a common design conditions
Commercial buildings spend most of their operating hours at part load and reduced ambient and new metrics like IPLV and IEER are more appropriate for equipment selection
The world has different climate conditions and although standards mostly use one common design conditions local climatic conditions need to be considered (sensible and latent)
Efficiency metrics are typical defined at a component level at standard rating conditions but do not always consider the full system and are not a good metric for system type selection
Ductwork pressure drop and airflow controls
Cooling tower approach and selection
Hybrid systems (economizers, free cooling, energy recovery, evaporative cooling, ventilation air control, etc.
Operational and Occupancy Controls
Large Office Zone 4a
Hospital Zone 4a
Building Models from ASHRAE 90.1 Reference Buildings
ASHRAE new climate zones
Total of 19 zones with 9 thermal zones and 3 subzones for humidity
ASHRAE has also defined benchmark cities for each of the climate zones

6. Improving Efficiency of Existing HVAC&R Systems
Building Inspection/Energy Audit – Complete a full inspection of the building and it’s energy use. ASHRAE has a standard called ASHRAE that includes procedures for level 1, 2, and 3 audits. A 2018 update is in progress and should be released later this year.
The audit data should be used to look at all the buildings energy use and not just the HVAC&R as plug load energy use. Also look closely at ventilation air requirements and operation.
Climate zones will have an impact on where to focus (i.e. hot/cold, humid/dry)
Review occupancy and building use and make sure it is still aligned with the original HVAC designs.
Recommissioning – In the US, as well as globally, we are beginning to see significant benefits by recommissioning the system, also using continuous commissioning and monitoring/diagnostics. (i.e. Seattle recently passed requirements for recommissioning every 5 years, Singapore has demonstrated significant savings, and green building standards are making monitoring of large system mandatory).
Monitoring and connected equipment and buildings is opening many new opportunities for maintaining higher performance buildings.
Controls Upgrades – Implement improvements like proper time of day scheduling (timeclock), occupancy setpoint scheduling, ventilation control (demand ventilation). Also check that controls are functioning properly and have been commissioned and not in manual control mode.

7. Improving Efficiency of Existing Systems
System Enhancements – Partial upgrades to systems can help improve efficiency
Use of variable speed fans/2 speed fans. For commercial system indoor fan power can be one of the largest loads due to continuous occupied operation for ventilation. Just a 66% speed of an indoor fan can reduce fan power by 70%. Be sure to coordinate with original equipment manufacturers to avoid reliability issues.
Add economizers and or free cooling options. A recent survey conducted by AHRI indicated that only 42% of units are installed with free cooling and the number should be closer to 70 to 80% based on energy and economic studies
Air Economizer – Use outside air for cooling
Hydronic/Fluid – Use cooling tower on water cooled system for cooling
Refrigerant Cycle Economizers – cooling without the compressor at lower ambient
Energy Recovery - For very hot and cold climates using higher levels of ventilation exhaust air energy recovery can reduce loads as well as in large buildings internal energy recovery can provide benefits for heating as well as domestic water.
Evaporative Cooling – In dry climates (B zones) evaporative cooling for condenser air and for ventilation air can add significant energy savings. Care should be to insure corrosion issues are not created with condenser coils and that there is proper water treatment

8. Improving Efficiency of Existing Systems
At some point replacing equipment should be considered
With the significant performance improvements due to regulations, equipment in the 10 year old range can have an acceptable payback, and there is the added benefit of a refrigerant change to lower GWP options.
Note in most cases the new low GWP refrigerants are not a drop-in
We sometimes see resistance to replacement due to US tax laws (depreciated life of 39 years), plus internal company capital limits (revised as of 2018 which allows first year expensing)
There is some discussion of making HVAC part of the building asset value
In the US there are significant rebate programs that can often help with system upgrades especially for higher Tier efficiency requirements, but you have to know where to look and comply with the requirements. US Utilities see efficiency improvements easier to implement then new power plants
When doing a unit upgrade the complete system should also be considered
Cooling tower upgrades for water cooled systems
Free cooling options, heat reclaim and hybrid systems
Renewable energy interface including storage
Look at plug loads
Variable speed airflow and variable speed water flow
Controls and monitoring
Multiple unit sequencing
Also consider load data (Energy Audits) and possible resizing of equipment

9. HVAC Cooling Energy Use for Commercial Office Building
The following chart summarizes some of the energy cost analysis using tools being developed for compliance that can help guide system upgrades and retrofits
Energy Cost includes chiller, cooling tower, chilled water pump, tower pump, indoor fan, exhaust fan and water cost
Analysis Assumption
400 Ton System
Dual path B ASHRAE 90.1 Chillers
Ventilation Air %
Electric Cost - $US $US /kW
Water Cost $US/kW
Sewage Cost $US/kW
Water Treatment Cost $US/kW
Analysis based on ASHRAE compliant system using reference buildings and cities

10. Summary
Considerable focus in US minimum equipment efficiencies which has created a very complex and resource intensive compliance and certification programs with multiple metrics and labeling requirements
For existing buildings there are multiple approaches for improvement
Energy Audits (ASHRAE 211) and review of system annual energy use
Commissioning and Recommission
Monitoring and Diagnostics
System Upgrades
Equipment Replacements and Upgrades (also upgrade refrigerants)
Financial Justification
Equipment upgrades require capital investment which typically require less than 4 year payback
Rebates from Utilities and Governments can help with upgrades
Consideration of new approaches (i.e. including HVAC&R in building asset)
Building Labeling increase value
Metrics (MEPs)
Simple full load metrics are not the best approach
Full modeling and building annualized analysis is the best, but less than 20% of buildings are modelled
New simplified tools and approaches are needed and are being developed