Summary

Advanced Rooftop Unit Controls (ARC) Retrofit

Rooftop Unit Controls: Advanced with Remote Access and Monitoring vs. Conventional On-site

Controllers to retrofit existing rooftop units to optimize performance by providing remote energy monitoring and control as well as variable speed drives, demand-controlled ventilation, and other features.

Synopsis:

This measure highlights rooftop unit (RTU) retrofit controls with supervisory capability for small commercial buildings and big box stores.To produce electrical energy savings, minimum requirements are supply fan control with a variable-frequency drive (VFD) or fan cycling control, upgraded economizer controls, and remote web control and monitoring. Additional desirable features include web-enabled scheduling and setpoint adjustment, energy and performance monitoring, demand-controlled ventilation (DCV), other control optimization, and basic measurement and verification data collection. Products from several manufactures can be utilized to achieve this (see Products section below).

RTUs are estimated to be used in 46% of all commercial buildings and serve about 69% of the cooled floor space in U.S. commercial buildings. A 2013 study by Pacific Northwest National Laboratory involved installing advanced controllers on 66 RTUs on eight different buildings involving retail, office space, food sales, and healthcare. Of the 66 RTUs, 17 were packaged heat pumps with the rest packaged air conditioners with gas heat.The advanced controllers reduced normalized annual RTU energy consumption between 22% and 90%, with the average being 57% for all RTUs.

This measure is very similar to ET #246 Advanced Design Rooftop Unit, which is an entirely new RTU because the advanced controls provide the great majority of the energy savings. For facilities with fairly new but code-minimum RTUs, this retrofit may be the best choice. Facilities with older RTUs may benefit more from a wholesale replacement of the RTUs.

BPA has tested field retrofits of Advanced Rooftop Control (ARC) (Wang, 2013), and in 2015 will begin field testing ARC-Lite. ARC-Lite limits the controls package to those that are the most cost-effective: adding variable speed and the ability to reduce fan speed to pre-set levels (BPAARC-Lite, https://www.bpa.gov/EE/Technology/EE-emerging-technologies/Projects-Reports-Archives/Field-Tests/Documents/FY15_ET_Field_Test_Pilot_Announcement_Final.pdf).

Energy Savings: 45%

Energy Savings Rating: Approved Measure What's this?

Level	Status	Description
1	Concept not validated	Claims of energy savings may not be credible due to lack of documentation or validation by unbiased experts.
2	Concept validated:	An unbiased expert has validated efficiency concepts through technical review and calculations based on engineering principles.
3	Limited assessment	An unbiased expert has measured technology characteristics and factors of energy use through one or more tests in typical applications with a clear baseline.
4	Extensive assessment	Additional testing in relevant applications and environments has increased knowledge of performance across a broad range of products, applications, and system conditions.
5	Comprehensive analysis	Results of lab and field tests have been used to develop methods for reliable prediction of performance across the range of intended applications.
6	Approved measure	Protocols for technology application are established and approved.

Simple Payback, Retrofit (years): 2.7 What's this?

Simple Payback is one tool used to estimate the cost-effectiveness of a proposed investment, such as the investment in an energy efficient technology. Simple payback indicates how many years it will take for the initial investment to "pay itself back." The basic formula for calculating a simple payback is:

Simple Payback = Incremental First Cost / Annual Savings

The Incremental Cost is determined by subtracting the Baseline First Cost from the Measure First Cost.

For New Construction, the Baseline First Cost is the cost to purchase the standard practice technology. The Measure First Cost is the cost of the alternative, more energy efficienct technology. Installation costs are not included, as it is assumed that installation costs are approximately the same for the Baseline and the Emerging Technology.

For Retrofit scenarios, the Baseline First Cost is $0, since the baseline scenario is to leave the existing equipment in place. The Emerging Technology First Cost is the Measure First Cost plus Installation Cost (the cost of the replacement technology, plus the labor cost to install it). Retrofit scenarios generally have a higher First Cost and longer Simple Paybacks than New Construction scenarios.

Simple Paybacks are called "simple" because they do not include details such as the time value of money or inflation, and often do not include operations and maintenance (O&M) costs or end-of-life disposal costs. However, they can still provide a powerful tool for a quick assessment of a proposed measure. These paybacks are rough estimates based upon best available data, and should be treated with caution. For major financial decisions, it is suggested that a full Lifecycle Cost Analysis be performed which includes the unique details of your situation.

The energy savings estimates are based upon an electric rate of $.09/kWh, and are calculated by comparing the range of estimated energy savings to the baseline energy use. For most technologies, this results in "Typical," "Fast" and "Slow" payback estimates, corresponding with the "Typical," "High" and "Low" estimates of energy savings, respectively.

Details

Advanced Rooftop Unit Controls (ARC) Retrofit

Rooftop Unit Controls: Advanced with Remote Access and Monitoring vs. Conventional On-site

Item ID: 338

Sector: Commercial

Energy System: HVAC--Rooftop Units & Air Handling Units

Technical Advisory Group: 2011 Energy Management TAG (#4)
Average TAG Rating: 3.5 out of 5
TAG Ranking Date: 09/29/2011
TAG Rating Commentary:

This technology can provide significant savings, although the savings depend on the functions that the controller supports.
These are interesting and promising but probably belong to the HVAC TAG/experts?
Technology sounds good, but belongs in HVAC TAG, not EM TAG
A controls system without verification of screen data is not always reliable or accurate. Any new controls on RTU-s should include video assistance to validate screen data.

Technical Advisory Group: 2015-1 Commercial HVAC TAG (#11)
Average TAG Rating: 3.7 out of 5
TAG Ranking Date: 03/10/2015
TAG Rating Commentary:

Works well for lots of packaged single zone equipment. Adds complexity and cost. Vulnerable to programming errors.
At least for Industry leaders and for those who have good results from third party evaluations. It is constantly changing and evolving.
BPA already has a measure for this technology, but it hasn't had much uptake. A recent call with 5 PNW utilities, indicated different requirements and limited non-energy benefits.
I think it is well established through work in California as well as by PECI, etc. The big question is how to do retrofits cost-effectively with the available technician pool.
I strongly support the RTU systems that have adjustable speed drives and demand ventilation controls with CO2 sensors. The SPEED program tested the Catalyst System and there are many other field demos showing 40-50% electrical savings and 10-30% HVAC savings. All RTUs need continual monitoring and commissioning to have long term savings.
This technology meets all 5 of the criteria admirably.
BPA first needs to develop a framework for quantifying the energy savings. Products continue to be offered by the marketplace, but currently a path does not exist to credibly quantify energy savings - a robust evaluation framework is needed.

Synopsis:

Baseline Example:

Baseline Description: Adjustments to HVAC Made During Scheduled Maintenance
Baseline Energy Use: 10.5 kWh per year per square foot

Comments:

The 2009 Commercial Building Stock Assessment gives the actual electrical building Energy Use Index (EUI) for various types of heating and cooling systems (CBSA Table D-EA5). Office buildings with electric heating and cooling have an EUI of 20.1 kWh/sf/year. Office buildings with no electric heating or cooling use only 8.2 kWh/sf/year, indicating that the combined HVAC heating and cooling energy use is 11.9 kWh/sf/year. (For all commercial buildings, the corresponding values are 19.9 and 9.4 kWh/sf/year, respectively.)Because this technology can be applied to many types of non-office buildings, a baseline energy use of 10.5 kWh/sf/year is assumed (NEEA, 2009).

Manufacturer's Energy Savings Claims:

"Typical" Savings: 35%
Savings Range: From 30% to 60%

Comments:

Energy savings will depend greatly on what features are implemented and the condition of the existing equipment to be retrofitted. Transformative Wave estimates energy savings of 25% to 50% (Transformative Wave, 2013). Bes-Tech estimates energy savings at 40% to 60%, and estimates peak demand reduction at 30% to 60% (Bes-Tech,2013).

Best Estimate of Energy Savings:

"Typical" Savings: 45%
Low and High Energy Savings: 24% to 90%
Energy Savings Reliability: 6 - Approved Measure

Comments:

BPA, in conjunction with Peninsula Power and Light, conducted an emerging technology field test on two 15-ton RTUs serving a small retailer. The measurement and verification (M&V) indicated a 45% reduction in total HVAC electrical energy use

(https://www.bpa.gov/EE/Technology/EE-emerging-technologies/Projects-Reports-Archives/Documents/ARC_casestudy.pdf). Energy savings of 60% are noted in a report by the Oregon Energy Office and the Northwest Energy Efficiency Alliance (NEEA), (Stipe, 2003).

A 2013 study by Pacific Northwest National Laboratory involved installing advanced controllers on 66 RTUs on eight different buildings involving retail, office space, food sales, and healthcare. Of the 66 RTUs, 17 were packaged heat pumps and the rest were packaged air conditioners with gas heat. The advanced controllers provided a reduction in normalized annual RTU energy consumption between 22% and 90%, with the average being 57% for all RTUs (Wang, 2013). A demonstration project involving 35 RTUs with a combined 202.5 tons of cooling at the Lawrence Middle School and the Los Angeles Center for Enriched Studies (part of the Los Angeles Unified School District) showed energy savings of 45% HVAC with Transformative Wave's Catalyst.

RTUs with DCV and economizer control features alone are found to save about 30% of energy use for most occupancies and locations.

A California State Partnership for Energy Efficient Demonstration project found HVAC energy savings of 51% at a California State University Long Beach dance complex and 29% at a San Diego State University aquaplex (Grupp, 2013).

Omaha Public Power District tested Digi-RTU with 30 RTUs and found 52% kWh savings and better humidity control (Sunde, et. al., 2011).

Snohomish County PUD tested CATALYST at one facility and found 48% kWh savings.

HPAC Engineering Journal (Aug 1, 2011) published a case study about an Enerfit installation with electrical savings of 53%. Some of these savings came from air leakage repairs performed when the Enerfit was installed.

The DOE Office of Energy Efficiency and Renewable Energy (EERE) will soon post a "Retail Energy Alliance" guide for retrofitting to VAV. An energy savings calculator for big box and grocery stores in 16 climate zones will show 50% to 75% fan energy savings.

Energy Use of Emerging Technology:

5.8 kWh per square foot per year What's this?

Energy Use of an Emerging Technology is based upon the following algorithm.

Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))

Technical Potential:
Units: square foot
Potential number of units replaced by this technology: 453,431,000
Comments:

RTUs are estimated to be used in 46% of all commercial buildings and serve about 69% of the cooled floor space in U.S. commercial building (Grupp, 2013). The cooled floor space in the commercial sector in the Northwest accounts for about 2,289.7 million square feet, according to table C-GB4 from a report from the Northwest Energy Efficiency Alliance (NEEA, 2009). Taking 69% of this total yields a potential of 1,579.9 million sf. This technology is most cost-effective for that portion (28.7%) of the regional conditioned floor area that uses electricity as the primary HVAC fuel. This brings the total square footage down to about 453,431,000 sf. Additional savings can be gained from the 66.3% of conditioned space that uses natural gas for space heat and electrical energy for cooling, although it will not be as cost-effective from the electric savings perspective. Therefore, the technical potential estimate here is understated or conservative.

It is not known what percentage of this floor space is already served by advanced rooftop controls, so we are estimating that none of it is, given that it is still an emerging technology.

Regional Technical Potential:
2.14 TWh per year
245 aMW
What's this?

Regional Technical Potential of an Emerging Technology is calculated as follows:

Baseline Energy Use * Estimate of Energy Savings (either Typical savings OR the high range of savings) * Technical Potential (potential number of units replaced by the Emerging Technology)

First Cost:

Installed first cost per: square foot
Emerging Technology Unit Cost (Equipment Only): $1.13
Emerging Technology Installation Cost (Labor, Disposal, Etc.): $0.01

Comments:

Installed cost for the advanced control units are approximately $450/ton for a 5- to 10-ton RTU (Wang, 2013). Assuming 1 ton of capacity for 400 sf, then the initial cost is $1.13/sf.

Note: This is a deemed measure under the October 1, 2014 BPA "Energy Efficiency Implementation Manual." The deemed amount for an advanced rooftop unit control retrofit is $150 to $225.

Cost Effectiveness:

Simple payback, new construction (years): N/A

Simple payback, retrofit (years): 2.7

What's this?

Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.

Comments:

This is more cost effective on larger RTUs, 8 to 10 tons or greater.

TES Engineering tested Enerfit in 11 buildings and found a payback of 2 to 3.5 years in nine buildings but it was not cost-effective in two buildings.

Detailed Description:

This technology provides a combination of optimized RTU controls and monitoring via a web interface. Minimum requirements to provide electric savings are supply fan control with either a variable-frequency drive (VFD) or fan cycling control, upgraded economizer controls, and remote web control and monitoring. Minimum and desired features are detailed below. As you can see, when studies report incremental cost and energy savings from advanced RTU controls, exactly what that means can vary. However, the estimates provided reflect the most commonly adopted set of features.

Minimum Control Requirements:
-Supply fan control (variable speed drive [VSD] or cycling)
-Demand controlled ventilation
-Digital integrated economizer control
-Differential economizer high limit

Minimum Monitoring Requirements:
-Web-based setpoints and scheduling
-Time series point monitoring (trending)
-Monitored point threshold alerts

Desirable Control Options:
-Occupancy vent and temperature standby
-Night flush cooling
-Demand management or response
-Split DX coil flow control
-Compressor variable control
-Condenser fan variable control
-Optimum start with OAT input

Desirable Monitoring Options:
-Fault detection and diagnostics
-Time-series energy monitoring
-Mode runtime
-RTU energy benchmarking (single unit)
-RTU energy benchmarking (multiple units)
-Demand response measurement and verification (M&V)
-Dashboard presentation

Considerations:
For the addition of a VSD, in most cases the motor does not need to be replaced. A VSD addition works best for three-phase motors. Small RTUs less than 7 tons tend to have single-phase motors, and cycling is more likely to be successful for these fans. In all cases where the fan speed is managed or cycled, provisions to vary ventilation with fan speed are required. Demand controlled ventilation provides the most successful approach.

Products:
• CATALYST efficiency enhancing controller (EEC), by Transformative Wave Technologies, the technology development division of Performance Mechanical Group. CATALYST includes demand controlled ventilation (DCV) and economizer controls.
• Enerfit, by ECI (Electronic Controls Inc.).
Enerfit also includes demand controlled ventilation (DCV) and economizer controls, fault detection and diagnosis (FDD) and a well-sealed damper. Enerfit is most cost-effective for single-zone multi-compressor systems that are 8 tons or larger.
• Digi-RTU Roof Top Unit Controller, by DTL Controls.
Digi-RTU has the option of adding VFD to the condenser fan.
• Optimum Energy Products is developing a comparable product

For DCV with fan cycling or VSD, the premium ventilation sequence can be implemented with Alerton VLD, Innotech innTOUCH/MicroMAX and KMC FlexStat. For these products, the VSD is an external unit controlled by the premium ventilation sequence that includes night flush, ruggedized optimum start and occupancy sensor standby.

Related Research:

(BPA ARC-Lite, https://www.bpa.gov/EE/Technology/EE-emerging-technologies/Projects-Reports-Archives/Field-Tests/Documents/FY15_ET_Field_Test_Pilot_Announcement_Final.pdf)

Product Information:
Innotech, innTOUCH Smart Sensor KMC Controls, FlexStat Alerton, AZW-5000 Transformative Wave, CATALYST Enerfit LLC, Enerfit Optimum Energy Products, Enterprise Energy Optimization Solutions Field Diagnostics, Synergy Bes-Tech, Inc., Digi-RTU

Standard Practice:

In the Northwest, 60% to 80% of economizers in existing RTUs do not work properly.

Even though 95%+ operation is at partial load, most RTUs have single-speed fans. At partial loads, these perform poorly.

While variable air volume (VAV) operation is well known, until now it has mainly been applied to centralized HVAC systems rather than packaged RTUs.

Development Status:

Early market introduction, some availability in the Northwest. See equipment under Detailed Description and Products sections above. See Advocates below for case studies.

Non-Energy Benefits:

Variable-speed operation is generally quieter than constant-speed equipment and improves equipment life. Earlier detection of equipment anomalies can lead to maintenance adjustments rather than more expensive equipment failures.

End User Drawbacks:

A primary barrier is first cost, which can be addressed with financial incentives.
Care should be taken to assure the existing blower motor can be equipped with a VSD without overheating.
For the small commercial building sector, an excellent promotional program is essential. Financial incentives alone are unlikely to get traction without excellent promotion.
Manufacturer's warranties may be violated, so it is best to check with equipment vendors.
To meet energy code requirements for fresh air despite slower fan speeds, this may require DCV or adjusting the damper along with the fan speed.

Operations and Maintenance Costs:

Baseline Cost: $100.00 per: square foot per year
Emerging Technology Cost: $100.00 per: square foot per year

Comments:

There should be no difference in maintenance costs.

Effective Life:

Anticipated Lifespan of Emerging Technology: 25 years

Comments:

The controller should last as long as the RTU it is attached to. The RTU might last longer if the new controller provides 'soft starts' on the compressors and blowers.

Competing Technologies:

Some energy management systems, such as the Kite & Lightning Unity, improve economizer function without adding VAV capability (see ET #347 Low-Cost Energy Management and Control System for Small to Medium Commercial Buildings). This issue can be addressed with an integrated control and monitoring solution. Alternately, a control solution can be coupled with an independent monitoring solution.

Reference and Citations:

Srinivas Katipamula, et al., 06/17/2013. Advanced RTU Campaign Webinar
U.S. Department of Energy, Better Buildings Alliance
Special Notes: A Better Buildings Alliance webinar presentation

BPA, 05/01/2012. Premium Ventilation Package Proof of Concept and Field Test
Bonneville Power Administration E3T

Mark Hancock, et. al., 2013. Advanced Rooftop HVAC Unit Controls Pilot
Minnesota Center for Energy and Environment

Reid Hart, et. al., 06/27/2011. Unitary HVAC Premium Ventilation Upgrade
2011 ASHRAE Winter Conference Technical Program

Judy Sunde, et. al., 2011. Digi RTU Optimizer Case Study: New Technology to Maximum Energy Efficiency
ACEEE Summer Study on Energy Efficiency in Industry

Marty Stipe, 06/01/2003. Demand-Controlled Ventilation: A Design Guide
Oregon Office of Energy for the Northwest Energy Efficiency Alliance

Herb Woerpel, 06/11/2012. Standards, Innovation Lead Rooftop Efficiency
Air Conditioning, Heating & Refrigeration News

Srinivas Katipamula, et. al., 11/2004. Demonstration of Smart Building Controls to Manage Building Peak Loads: Innovative Non-Wires Technologies
Pacific Northwest National Laboratory

Heschong Mahone Group, 09/19/2012. Advanced Controls Retrofits For Packaged HVAC Systems in Small and Medium Commercial Buildings
Pacific Gas and Electric Company

Maggie Gulick, 08/21/2012. NBI Puts High Performance HVAC Units to the Test
New Buildings Institute

Better Bricks, 04/28/2010. 2010 Puget Sound BetterBricks Awards - Service Contractor (YouTube video)
Better Bricks

Peter Criscione, 09/20/2011. Pump Down the Volume and Chill: Converting to Single-Zone VAV
24th Annual E Source Forum

Scott Arnold, 08/01/2011. Retrofit System, Variable-Frequency Drive Cut Energy Costs and Increase Comfort
HPAC Engineering

Transformative Wave, 2013. Catalyst: The Proven RTU Retrofit Solution
Transformative Wave Technologies

CADMUS, 12/21/2009. Northwest Commercial Building Stock Assessment (CBSA): Final Report
Prepared by the CADMUS Group for the Northwest Energy Efficiency Alliance

W. Wang, et. al., 07/01/2013. Advanced Rooftop Control (ARC) Retrofit: Field-Test Results
Pacific Northwest National Laboratory

David Grupp, et. al., 05/01/2013. RTU Efficiency Optimizers
CA State Partnership for Energy Efficient Demonstrations

Rank & Scores

Advanced Rooftop Unit Controls (ARC) Retrofit

2015-1 Commercial HVAC TAG (#11)

Technical Advisory Group: 2015-1 Commercial HVAC TAG (#11)
TAG Ranking: 2 out of 29
Average TAG Rating: 3.7 out of 5
TAG Ranking Date: 03/10/2015
TAG Rating Commentary:

Works well for lots of packaged single zone equipment. Adds complexity and cost. Vulnerable to programming errors.
At least for Industry leaders and for those who have good results from third party evaluations. It is constantly changing and evolving.
BPA already has a measure for this technology, but it hasn't had much uptake. A recent call with 5 PNW utilities, indicated different requirements and limited non-energy benefits.
I think it is well established through work in California as well as by PECI, etc. The big question is how to do retrofits cost-effectively with the available technician pool.
I strongly support the RTU systems that have adjustable speed drives and demand ventilation controls with CO2 sensors. The SPEED program tested the Catalyst System and there are many other field demos showing 40-50% electrical savings and 10-30% HVAC savings. All RTUs need continual monitoring and commissioning to have long term savings.
This technology meets all 5 of the criteria admirably.
BPA first needs to develop a framework for quantifying the energy savings. Products continue to be offered by the marketplace, but currently a path does not exist to credibly quantify energy savings - a robust evaluation framework is needed.

2011 Energy Management TAG (#4)

Technical Advisory Group: 2011 Energy Management TAG (#4)
TAG Ranking: 1 out of 59
Average TAG Rating: 3.5 out of 5
TAG Ranking Date: 09/29/2011
TAG Rating Commentary:

This technology can provide significant savings, although the savings depend on the functions that the controller supports.
These are interesting and promising but probably belong to the HVAC TAG/experts?
Technology sounds good, but belongs in HVAC TAG, not EM TAG
A controls system without verification of screen data is not always reliable or accurate. Any new controls on RTU-s should include video assistance to validate screen data.

Technical Score Details

TAG Technical Score: 3.4 out of 5

How significant and reliable are the energy savings?
Energy Savings Score: 3.9 Comments:

Nov 2011 Comments:
1. I would like to see more savings/performance data before committing in a significant way to these technologies (launching a mainstream program), but the preliminary data suggest these products are ready for pilot programs/testing.
2. It's rare to get these kinds of big energy savings so readily. The only drawback is that they're likely to vary from unit to unit based on the baseline condition of the equipment.
3. Savings appear to be significant, but highly variable and difficult to predict. Overall this is promising on the energy savings side.
4. It looks like most of them need a bit more independent testing. But it looks good to start installing units and getting a better read on what they can provide and would provide insight into how we claim energy savings for these approaches.
5. Existing RTUs can have very different maintenance conditions. Baseline should be a properly operating "tuned up" unit rather than the measured baseline.
6. The energy savings can be significant depending on what the controller is capable of doing. The controller should have at a minimum multi-speed or variable-speed supply fan, demand controlled ventilation and integrated economizer control.

PNNL has recently completed an impact assessment (energy and cost savings) of an advanced controller for RTUs. The simulation results indicate significant savings in fan and cooling energy electric consumption and gas consumption for heating. The report will be available at the end of the month."
7. Potential savings are high. Quality control in realization of potential savings may be challenging.
8. Good for larger units but payback may be high until cost comes down
9. High potential savings, but leans toward gas. Also savings is variable from one unit to the next; but good program wide
10. SCE is evaluating the Digi RTU and Catalyst currently at Macerich properties

How great are the non-energy advantages for adopting this technology?
Non-Energy Benefits Score: 2.9
Comments:

Nov 2011 Comments:
1. Humidity improvements have been demonstrated in a small sample thus far and reduced maintenance /increased RTU reliability have a theoretical basis.
2. If natural gas counts as a non-energy benefit, sounds like there are plenty here. These packages crank out lots of good information on the packaged RTUs themselves, which some customers will likely find very valuable for servicing.
3. Based on comments form some of RTU field studies, small commercial customers have responded very positively to a web interface that shows clearly when each RTU is running. Diagnostics are somewhat of a benefit, but do not seem to be as compelling for most small commercial owners. So with a good web interface I would rate at 4, without at a 2 to 3 for good diagnostics.
4. Could assist with maintenance
5. Potential for better humid control and indoor air quality.
6. Can be used for trouble shooting
7. Significantly improved ventilation

How ready are product and provider to scale up for widespread use in the Pacific Northwest?
Technology Readiness Score: 3.3
Comments:

Nov 2011 Comments:
1. For the four retrofit CAV to VAV packaged products, vendors will take some time to ramp up production.
2. With just 4 young vendors and virtually no delivery network in place in the PNW, it sounds like a bunch of work needs to be done here.
3. There has been considerable ground work done on RTU retrofits, by Reid Hart and others. The big change I see here is the entry of Catalyst product, and others following. Without these product lines, I would rate technology readiness lower, but projecting out over the next few years, I rate it higher now. These are not simple retrofits, so it will take several years of learning by contractors.
4. Sounds promising - need large scale pilot to improve
5. Yes, the technology is ready, but needs validation of results and reliability of controls.
6. Testing and training of installers needed
7. Control products ready, Web interfaces need some development,

How easy is it to change to the proposed technology?
Ease of Adoption Score: 3.3
Comments:

Nov 2011 Comments:
1. It remains to be seen how easily these products can be installed by the vendor's installation/service/contractors networks. However, if you're installing a retrofit CAV to VAV controller, you can do an RTU tune-up at the same time, enabling the capture of a larger amount of savings. In addition, the continuous monitoring/FDD capability could help these energy savings persist. So in that sense these products make it easier to capture a larger chunk of savings.
2. Sounds like largely a bolt-on on existing equipment.
3. Not a simple retrofit. Although no big risks are apparent.
4. Not sure if most customers will have someone sitting at the dashboard for this size of customer, Having the HVAC companies using this tool may be a viable route to develop
5. Not much different, although some usability testing would be good.

Considering all costs and all benefits, how good a purchase is this technology for the owner?
Value Score: 3.4
Comments:

Nov 2011 Comments:
1. If the savings data can be verified through pilots and the development of installation/service networks by the vendors result in reliable installations, given the large savings seen in the preliminary data, this type of product would be a great buy.
2. Given all the problems these packages solve, sounds like they offer excellent value. It just remains to be seen if they can really do so at scale.
3. Savings will vary. For the best opportunities, payback should be excellent, for other projects, not so good. Right priced solutions need to be developed and understood. So value varies from poor to best right now.
4. It depends on the product. Some are more intuitive than other. I think tests of these products would be able to provide insight into this.
5. Need verification of software accuracy and application criteria to more fully understand
6. This is such a broadly applicable topic that it deserves serious support.
7. Considering that savings are going to be attractive, the technology will bring a lot of value.
8. I like the idea of BPA issuing a information consumer pamphlet. The feds should probably put together an energy star rating program wih minimum specifications and labeling requirements.
9. Web enabled scheduling and monitoring will require training of end user and paybacks may be long

Completed:
1/20/2012 9:34:45 AM
Last Edited:
1/20/2012 9:34:45 AM

Market Potential

Advanced Rooftop Unit Controls (ARC) Retrofit

Last Edited:

12/6/2012 3:24:19 PM by AngelaP

Market Segment:

All commercial office buildings.

Regional Fit:

This technology is a good fit in the Pacific Northwest if it has the following features: 1) multi-speed or variable speed supply fan, 2) demand controlled ventilation, and 3) integrated economizer controls all packaged into the advanced RTU Controller. There will be significant savings in electricity used by the supply fan and the compressor and gas.

However, Mark Rehley at NEEA says that 80% of RTU's in the Pacific Northwest have a capacity of less than 10 tons. These retrofits are less cost-effective for RTU's of less than 10 tons, until the price of the retrofits comes down.

Zones:

Heating Zone 1, Heating Zone 2, Heating Zone 3, Cooling Zone 1, Cooling Zone 2, Cooling Zone 3

Load Shape:

CommCOOL

CommHEAT

Performance Trajectory:

Gradual improvement. Adoption of the technology will increase when incentives and programmatic information becomes available.

Cost Trajectory:

Gradual decrease. The cost will go down as adoption of the technology increases.

Product Supply and Installation Risk:

The technology can be deployed now. There are a number of installations in the Pacific Northwest and in other parts of the U.S. There is one manufacturer in the Northwest and a few more elsewhere in the U.S. There is more than one vendor of the product and it is likely that there will be others if the technology is accepted more broadly. If widespread adoption of the technology occurs too fast, there could be a problem in meeting the needs.

Because the technology can be installed by most HVAC service providers, there should not be problems finding the installers.

Technical Dominance:

This technology only applies to existing RTUs and packaged units. Some manufacturers are already making new products that will have controls options like the one being considered. This technology is a bridging technology that could dominate the market for the next 2 decades. Eventually, the RTUs and packaged equipment will have these features as default features.

Target Customer:

Building owners or operators are the key users. Architects, engineers, and contractors are the key specifiers.

Market Channels:

The known market barriers include first cost, although the technology should have reasonable payback (three years).

To encourage widespread adoption of the technology, active participation of the utilities is needed for marketing the product and providing incentives for installations.

Regulatory Issues:

There are no known code, standard or regulation issues.

Other risks and barriers:

The main barrier is a lack of uniform guidelines for specifiers to make implementation easy and uniform from project to project.

Basis of Savings:

In most cases, savings can be estimated using a deemed calculator. The savings are function of a number of parameters: 1) run time of the units, 2) cooling degree days, 3) heating degree days and 4) size of the unit. The savings will increase, if the units’ economizer is not functioning properly. If the unit uses gas heating, the total savings will also include significant gas savings.

Completed:

12/6/2012 3:24:19 PM by AngelaP