1. Texas Utility Innovations
A discussion on
HVAC’s Variable Refrigerant Flow (VRF) Technology & IEER Efficiency Metrics
Steve Jones - Southwest Business Unit Commercial Manager – Mitsubishi Electric
Nick Conklin LEED AP, PE, CEM – Application Engineering Manager – Mitsubishi Electric
Good morning (afternoon). We’re going to spend the next 15 minutes talking about innovations in HVAC technology – specifically the HVAC industry’s newest technology called Variable Refrigerant Flow Technology (or VRF). We also want to discuss how the efficiency metric, Integrated Energy Efficiency Ratio (IEER), is being used to accurately predict energy savings and assist utilities in developing programs to incentivize growth for this energy saving technology.

2. EEIP Guidelines to Address
Why is Ductless Heat Pump (DHP) / Variable Refrigerant Flow (VRF) a Commercially-ready new technology or existing underutilized technology?
Overview of the DHP/VRF for EECM(s) – A description of the technology, target market with market potential, and estimated installed/implementation costs
Why Verifiable peak demand savings (kW) and/or energy savings (kWh) is achievable?
Energy Modeling using IEER metrics
Energy Saving Case Studies – Sacramento Drill Tower
Measurement and Verification (M&V) – SMUD and PG&E utility savings
Applicability in Texas Utility Market
SOP
MTP
What are Texas PUC needs for Energy Efficiency Conservation Measures and/or the Energy Efficiency Goal ? How do we get VRF and IEER metrics in place for utility programs?
Here are the EEIP Guidelines that we want to address today.
One of our main questions for PUCT is - what PUCT is hoping to learn from this session and how Mitsubishi Electric can support this process with future more in-depth meetings?
What are the next steps in this process?

3. US HVAC Industry Overview
Commercial/Industrial HVAC Choices:
Package Systems
Split Systems
VRF Systems
Light Commercial/Residential HVAC Types:
PTACs
Unitary
Window units
Wall-mounted units
Radiant
Ductless (DHP)
All buildings have some type of heating, ventilation and air conditioning. For large commercial and industrial applications, HVAC options fall under one of these three categories:
Package Systems – the HVAC system is contained in one unit. This type of HVAC system can include traditional boilers, chillers, water-source heat pumps, multi-zone rooftop units – basically any system that is based on water or direct expansion (DX). Typically, conditioned air is ducted from the system to the indoor space through ducts.
Split Systems – the system has two parts, usually an indoor and outdoor unit. Again, the components of this system can include boilers, chillers, water source heat pumps, etc. Typically, these systems move refrigerant instead of air.
VRF Systems – a flexible version of both of the more traditional options, with the key difference being that VRF reacts to changes in cooling and heating requirements by varying the flow of refrigerant as opposed to moving chilled or heated air through ductwork. This is the newest and most exciting HVAC technology choice.
For smaller residential and light commercial buildings, common HVAC solutions include PTACs, unitary (traditional central air conditioning), window units, wall-mounted units, radiant and ductless.
*Room AC not included in analysis
Source: AHRI and BRSI, September 2012

4. US Vertical Market Opportunities
31% HVAC Unit Growth
Vertical Market
Year
Market Size (Units)
Education
2007
190,000
2012
300,000
Government/ Military
84,000
97,000
Health Care
79,000
145,000
Lodging
40,000
54,000
Multi-Family
270,000
317,000
Office Building
74,000
104,000
The tide is turning, however. The market is moving from what some would describe as “horse and buggy” technology to state-of-the-art solutions. This has already happened in other parts of the world where VRF technology is the preferred way to control interior comfort. There continues to be a strong need in a number of vertical markets for the solutions that ductless and VRF systems provide. These markets – education, government/military, healthcare, lodging, multifamily and offices – represent just a portion of the opportunity. Other key vertical markets include churches and public buildings such as museums, civic centers and performing arts facilities.
Source: FMI 2008 U.S. Market Construction Overview

5. Ductless Heat Pumps for Single Zones (30+ Years HVAC Market Success)
Highly Efficient
26 SEER
10.6 HSPF
No ductwork = No duct losses
Individual Room Control
Extremely Quiet
19 – 38 dB
Cold Climate Capable
100% capacity at 5 F.
82% capacity at -13 F.
This is the most basic type of DHP – Ductless Heat Pump system, often referred to as Ductless Mini-Splits. It has one outdoor unit to one indoor unit. It cools and heats the space or zone and has it’s own control mechanism. With most manufacturers – the outdoor unit has an inverter compressor (variable speed device) to control how much refrigerant is sent to the indoor unit. The indoor unit senses the required cooling or heating capacity (refrigerant flow from the outdoor unit) and increases or decreases fan speed with an ECM (electronically commutated motor) to condition the indoor zone. In many applications these are used to better condition a room addition or “hot / cold zone” in the residence/building. They are also used to help “displace” the existing central AC/Heat in the main part of the house/building to lower energy use.

6. VRF for Commercial Buildings
Up to 50 indoor units per outdoor
72,000 – 360,000 BTUH
Simultaneous heating and cooling
Energy reclaim
IEER up to 23.9
COP up to 4.87
VRF Systems are the enhanced commercial versions of Ductless Mini-Split systems. VRF systems permit more indoor units to be connected to the outdoor unit and offer additional features such as Simultaneous Heating and Cooling different zones and Heat Recovery.

7. What is VRF Technology?
VRF technology is a HVAC technology solution to efficiently condition buildings, zoned for comfort. This is accomplished through the use of an inverter driven (variable speed) compressor. The system is made up of a central variable capacity outdoor unit connected to multiple variable capacity indoor units. A typical installation considers a building’s diversity, driven by a variety of circumstances, including time of day, exposure to sun and other elements, and the occupants. Because the compressor can vary its speed and capacity, and the indoor units can very their capacity; the system delivers the capacity to precisely meet the load in each zone. 7

8. INVERTER-driven Compressor
SETPOINT
VRF
VRF
CONVENTIONAL
Room Temperature
Enables capacity operation as low as 4%
Sizing flexibility with variable capacity
Enables long runtimes
Reduces compressor cycling
Improves temperature control
VRF
The chart shows the advantage of inverter-driven compressors common in most VRF systems. Uniform temperatures are maintained as a result of finely tuned control of the compressor speed. Traditional HVAC systems, maintain temperatures by turning the compressor off and on, demanding the maximum energy input each time the system starts.
Time 8

9. High Starting Current Traditional HVAC System without Inverter Technology
The installation of variable speed air conditioning systems, motors, and drives is already an EECM in the state of Texas. VRF Inverter Compressor Technology is the same type of technology as a Variable Frequency Drive used for electric AC motors driving fans and pumps.
This is an important aspect for Demand Response Tools – as the VRF Control System can accept a signal from the Building Management System once the Demand Response trigger is initiated. The VRF controls then slow down the inverter compressor reducing energy demand from the VRF system, but allowing the VRF system to continue to provide reduced amounts of AC/Heat to the building occupants – versus an on/off situation – and occupant discomfort.

10. Diversity Solar Load Occupant Load Building Use 10
Utilizing a building’s diversity is a key advantage of VRF systems. These systems can distribute cooling capacity to keep up with changing solar loads, or as people travel throughout a building. They can cool and heat simultaneously, to provide heat at the perimeter and cool the interior of a building without any waste heat. 10

11. VRF Heat Recovery Technology
A simultaneous cooling and heating (heat recovery) system includes an outdoor unit, a BC controller, indoor units and a control system. Heat recovery systems take further advantage of diversity by taking the energy used to cool one part of the building and using it to heat another part of the building. Because of this feature, heat recovery systems are offered with a connected capacity of up to 150 percent. Typically, these systems are available up to 24 tons.
Simultaneous cooling and heating

12. VRF Integrated Controls
Easy to install and operate
2-wire DDC (Direct Control) system
16ga stranded and shielded, non-polar
Daisy-chain connection
Customizable control scheme with web access
Individual room controls
Color touch screen centralized control
Integration into building management system via BACnet® and Lonworks®
Third-party equipment control
Tenant billing capability
VRF systems utilize an integrated controls network that links the entire system. The integrated controls network allows all parts of the VRF system to communicate, constantly maximizing efficiency and dialing in the capacity of the system. The controls network can be tied into a standard building management system (BMS). The controls network also offers Tenant Billing which when combined with watt meters at the outdoor gives the building owner the ability to bill each tenant individually.

13. VRF Energy-Efficiency and Environmental Impact13

14. Demand Response Tool VRF Integrated Control Systems can allow:
Load shedding by automatically reducing compressor frequency/hertz (speed).
On/Off Sequencing between zones to minimize temperature discomfort
Turn off indoor units in several zones and allow temperature/humidity drift
Sequential starting of outdoor units to minimize demand power spikes
The Integrated Controls that come standard with VRF Systems allow a Building Management System to control the VRF System once a Demand Response Signal is sent. There are a variety of options that can be deployed to help minimize energy consumption without completely shutting the HVAC system off. The VRF Controls allow customized energy shedding options that the building owner determines are best suited for their needs.

15. Utilizing VRF with LEED
Energy and Atmosphere: VRF Can achieve up to 21 points
Environmental Quality: VRF can achieve up to seven points
LEED NC 3.0
Certified: points
Silver: points
Gold: points
Platinum: 80 + points
VRF system can contribute a great deal to meeting LEED requirements providing up to 21 points in Energy and Atmosphere and seven point in Indoor Environmental Quality.

16. Energy and Atmosphere Credits
Eac1 – Optimize Energy Usage
Total energy usage of building
Verified by modeling versus base building
EAc5 – Measurement and Verification
Verify actual building operation
Monitor equipment operation through integrated software
In the Energy and Atmosphere section of LEED, VRF systems help in optimizing energy performance, providing Maintenance Tool software for accountability and optimizing building energy consumption over time.

17. VRF Systems and Energy Modeling
Energy usage and cost for VRF systems can be modeled using EnergyPro
EnergyPro uses DOE2.1e to model and compare VRF to other HVAC system
EnergyPro is approved use with LEED EAc1
Through a partnership with EnergySoft, selected VRF manufacturers helped integrate VRF functions into an existing software tool – called EnergyPro – which can be used to model VRF systems. EnergyPro energy modeling results are acceptable for use in LEED documentation (EAc1). EnergyPro is available to designers and engineers at a discounted price through many VRF manufacturers. To date, EnergyPro is the only software with the capability to model VRF systems.
VRF system can contribute a great deal to meeting LEED requirements providing up to 21 points in Energy and Atmosphere and seven point in Indoor Environmental Quality.
In the Energy and Atmosphere section of LEED, VRF systems help in optimizing energy performance, providing Maintenance Tool software for accountability and optimizing building energy consumption over time. 17

18. EAC1 - Energy Cost Savings
The chart above shows the total building energy cost results of an energy model comparison done on a single story school. The building was set up to be code compliant. The only factor that was changed was the HVAC system. The VRF system was compared to a 4-pipe fan coil unit system, a water source heat pump system, and a packaged VAV with hot water reheat. In many cases installing a VRF system met or exceeded the 10 percent energy cost savings required by prerequisite and also meets or exceeds the 12 percent required to achieve points under EAC1.
VRF Total Energy Cost Savings

19. Overview of System Standards
AHRI 1230
Covers multi-split air conditioners and multi-split heat pumps with distributed refrigerant technology
ASHRAE 90.1
Minimum requirements for energy efficient building design
Higher standard for VRF system Integration Energy Efficiency Ratio (IEER) in ASHRAE standard 90.1 (July 2012)
DOE
DOE to reference AHRI 1230 Standard and ASHRAE 90.1 minimum efficiency standards in Code of Federal Regulations part 10, section 431

20. How IEER Weighting Factors Developed
To Develop the four weighting factors for the IEER equation as well as the ambient temperature schedule, a comprehensive model was developed :
Weather Data Model For Cities From 15 US Climate Zones
Percentage of Time In The Four Load Bins 100%, 75%, 50%, 25%
Average Ambient For Each Load Bin
3 Buildings types – Office (40%), Retail (30%), School (30%)
Each building type with its load profile vs. ambient schedule
Sales Volumes Percentage By Each Climate Zones

21. Sacramento Drill Tower
VRF Case Study
Owned by the City of Sacramento, CA
Concrete Building with Upper 1/3 being a water tank
Approximately 2/3 of the first floor area are offices and a training room, arranged like a donut
Original HVAC was 4 pipe ducted fan coils, with a natural draft gas boiler and 30 ton air cooled chiller.
Equipment replaced with (2) 16 ton VRF heat recovery type systems in 2008, with 4 ducted fan coils each, and an ERV

22. Sacramento Drill Tower – VRF Case Study
Significant reduction in Energy Consumption (kWh)

23. Metered Data From Drill Tower

24. Metered Data From Drill Tower

25. Metered Data From Drill Tower
Total Gas Cost
Total Electrical Cost
Total Cost
Before CITY MULTI - VRF (2007)
$5,987.44
$19,456.78
$25,444.22
After CITY MULTI - VRF (2009)
$455.03
$18,607.36
$19,062.39
Percent Savings
92.4%
4.4%
25.1%
*Based on Data Provided from SMUD and PGE Building is located in Sacramento

26. Re-Cap: Benefits of VRF Systems
Space Utilization
Installation flexibility to meet building space requirements
Minimal impact to existing building architecture and structure
Occupant Comfort
Individual comfort control
Indoor unit flexibility to meet the needs of any space
Meets occupant ventilation air requirements
Quiet operation
Energy Savings
Inverter driven compressor
No waste heat
Meets requirements for LEED points

27. Texas Utility SOP / MTP Programs In closing, I would like to ask the board to please support the development of programs in the state that appropriately incentivize VRF systems. By adding a VRF category to the Texas Energy Efficiency Goal utilizing the appropriate energy efficiency metric IEER, utilities will accurately capture the associated energy savings and properly incentivize the technology. 27

28. Additional Information Support Slides28

29. Successful Utility Programs - West
Prescriptive VRF Incentive
$1,500/ton upstream rebate on up to 80 tons for commercial applications
Let’s take a look at a couple successful VRF incentive programs in the US. SCE put a VRF incentive program in place in 2010 and PG&E followed along with a program in This incentive is an upstream rebate to the VRF distributors, and provided a range from $630 to $1,530 a ton for up to 80 tons for commercial applications. Quite a lucrative rebate indeed.

30. Calculating IEER

31. IEER Factors - Modeling Results
Weighting Factors
Bin-Average Ambient Values

32. Performance Incentives for Electric Efficiency - Texas

33. Mitsubishi Stocking Distributors
139 distributor organizations
1,114 distributor branches D

34. Mitsubishi Contractor Network
6,981 Contractors
1,030 “Diamond Dealers”

35. Mitsubishi Engineering Firms
6,495 architects and engineers
1,230 trained architects and engineers