CEE and Seventhwave lead a rapid-fire discussion of innovative tech and program approaches, and the most meaningful recent research findings for utility representatives, efficiency program implementers, and both residential and commercial field experts.
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Cold-Climate Research Round-Up
1. Cold-Climate
Research Round-Up
A Bi-Annual Webinar Series |
Center for Energy & Environment and Seventhwave
On the ground impacts & opportunities for leading edge,
clean energy technologies & services.
2. The Purpose
A semi-annual webinar series to share leading field research
& expertise on efficient and clean energy solutions,
particularly relevant for cold climate applications.
Next webinar: July 2017
3. Our Expertise
• Conduct primary research in the field
• Produce market characterizations & potential studies
• Provide training & engagement to convey new info
• Provide services and consulting to entities that are looking to
increase clean energy & conservation
CEE | 8 Dedicated research staff
Seventhwave| 5 dedicated research staff
4. Today’s Round-Up
• Commissioning for daylighting controls
• Optimizing operation of buildings with indoor pools
• Energy Recovery Ventilation effectiveness
• Maximizing energy savings from Demand Control Ventilation
• Cold-Climate Variable Refrigerant Flow optimization
• Innovative aerosol envelope sealing
• Next generation Air Source Heat Pumps
• Hybrid geothermal achieves highest performance
5. Pg. 5
Many of these projects were supported by a grant funds from the MN
Department of Commerce, Division of Energy Resources through the
Conservation Applied Research and Development (CARD) program.
6. Today’s Round-Up
• Commissioning for daylighting controls | Seventhwave
• Optimizing operation of buildings with indoor pools
• Energy Recovery Ventilation effectiveness
• Maximizing energy savings from Demand Control Ventilation
• Cold-Climate Variable Refrigerant Flow optimization
• Innovative aerosol envelope sealing
• Next generation Air Source Heat Pumps
• Hybrid geothermal achieves highest performance
7. Today’s Round-Up
• Commissioning for daylighting controls
• Optimizing operation of buildings with indoor pools | CEE
• Energy Recovery Ventilation effectiveness | CEE
• Maximizing energy savings from Demand Control Ventilation
• Cold-Climate Variable Refrigerant Flow optimization
• Innovative aerosol envelope sealing
• Next generation Air Source Heat Pumps
• Hybrid geothermal achieves highest performance
8. Areas of expertise:
Energy efficiency programs
Field research
Market characterization
High performance design
Education and training
11. Research Approach
Monitored 20 spaces across 10 buildings
Period 1 Energy
Period 1 Savings
Current
without
photocontrol
Period 3
Energy
Period 3
Savings
14. Pg. 14
Optimizing Indoor Public Pools
A high energy intensity area with specialty
HVAC systems
Russ Landry P.E. | Senior Mechanical Engineer
15. Pg. 15
Indoor Public Pools
Why we took a look | We’ve seen big energy saving opportunities in other
facilities with specialized HVAC systems, such as ice arenas.
Research Objective | Determine energy cost savings from improvements
& develop guides for operators and recommissioning providers.
Extent of Project Efforts
• Literature review & identification of indoor public pools in Minnesota
• Surveys of 30 sites
• Recommissioning and savings verification for 5 sites
• Guides for pool operators and recommissioning providers.
Notable Previous Work
• Pool operator certification manuals
• DOE sponsored RSPEC! software
Conducted
Jan 2014 – May 2017
Indoor Public Pool Optimization
16. Pg. 16
Technology in Brief
Indoor Public Pool Optimization
Pool Water
Heating &
Filtering
Space Ventilation,
Heating &
Dehumidification
84°F 55% RH
82°F
17. Pg. 17
Headline Findings & Observations
Energy & Cost Savings
• Some consistent, “prescriptive” type opportunities
• Site-specific control & operational “problems”
• Some “common wisdom” not true for cold climates
• Biggest savings for heating fuel (some electric hvac)
Barriers to Field Implementation
• Contractor & manufacturer execution of control details
• Often poor BAS link with HVAC & pool water heating
• User & operator upkeep: cover & controls
Bright Spots & Opportunities
• Cover
• Cost-effective control fixes
Indoor Public Pool Optimization
19. Pg. 19
Benefits Beyond Energy
Building Operators
• Reduced Comfort Complaints
• Simple Actions with Clear Directions from Operations Guide
Building Owners
• Reduced Comfort Complaints
• Equipment Longevity
• Facility Longevity
Indoor Public Pool Optimization
20. Pg. 20
How to Use This Information
How you can use this information today, take action, or
access more tools…
• www.mncee.org/pool
• http://smartenergy.arch.uiuc.edu
• http://www.rlmartin.com/rspec/software.htm
Indoor Public Pool Optimization
21. Pg. 21
Energy Recovery in Commercial and
Institutional Buildings
Do energy recovery systems meet performance
expectations?
Josh Quinnell Ph D | Senior Research Engineer
Minnesota Conservation Applied Research
and Development (CARD) Grant Program
22. Pg. 22
C&I Energy Recovery
Why we took a look
• Anecdotal impression that ERVs may not live up to savings potential
Research Objective
• Characterize ERVs in Minnesota, determine extent of problems, study a
subset of representative ERVs in detail
Extent of Data Collected
• Data collected on 400 commercial & institutional ERVs
• Screened 30 ERVs for study
• Selected 9 units for detailed study, measurements, and long term
monitoring
Notable Previous Work
• Prior work is design focused, usually on the cooling side
• Stops short of the practical issues associated with expectations,
installation, and operations
Conducted
Jan 2014 – Dec 2016
Commercial and Institutional Energy Recovery
23. Pg. 23
Exhaust Air-to-Air Energy Recovery
Ventilation (ERV) in Brief
• Purpose: Transfer energy between exhaust
air and outside air to lower
energy load of building
ventilation
• Relevance: Increasing code
requirements
• Performance Expectations:
• 40 - 85% heating savings
• 0 – 20 % cooling savings
Commercial and Institutional Energy Recovery
24. Pg. 24
General Findings & Observations
Expectations: ERVs are just another HVAC system
• Properly designed, installed, and operated ERVs typically achieve
design performance
Reality: Barriers to ERV Performance are practical
• There are no consistent expectations for ERV performance
• 80% of the problems occur during installation or operation
• Problems persist because expectations aren’t established and
other HVAC systems compensate
Opportunity: Most lost recovery is an easy fix
• A small number of issues were responsible for the vast majority of
energy penalties
Commercial and Institutional Energy Recovery
25. Pg. 25
Problems on ERV systems
• 75 issues discovered and 51 corrected
• Energy savings increased $40,683 -> $57,851 for 9 units or 0.30
to 0.42 $/supply-cfm
• 15% of issues responsible for 92% of lost energy recovery
0
2
4
6
8
10
12
Frequency
26. Pg. 26
Problems Encountered on ERVs
Commercial and Institutional Energy Recovery
High functioning units – 33% units / 8% problems
• Design-bid-build projects
• Robust documentation & commissioning process
• Typically found only neglected maintenance items
Functioning units – 33% units / 38% problems
• Awareness of minor problems, frustration or confusion about unit
operation
• Odd sequencing, BAS issues, sensor, scheduling, and set point problems
Dysfunctional units – 33% units / 53% problems
• Awareness of minor problems, no awareness of major ones
• Heat recovery casually disabled and poor installation
27. Pg. 27
Opportunities
Commercial and Institutional Energy Recovery
Text book examples of ERV applications are common!
•We know that dramatic energy savings are possible in practice
•Robust documentation, commissioning, and hand off are key to success
•Improving general maintenance is still an opportunity for the best systems
Most problems don’t seriously inhibit energy recovery!
•Consistent with the types of problems reported outside this work
•There is still a huge opportunity; these problems indirectly impact expectations
and impressions of energy recovery –typically unrelated to actual recovery
performance
It’s easy to identify dysfunctional units!
•If a unit runs 5 ᵒF– 45ᵒF and above 75ᵒF, 85% savings are achieved
•In many situations it is easy to casually disable energy recovery, but it’s also
easy to re-enable it and perform basic training about specific controls
28. Today’s Round-Up
• Commissioning for daylighting controls
• Optimizing operation of buildings with indoor pools
• Energy Recovery Ventilation effectiveness
• Maximizing energy savings from DCVs | Seventhwave
• ccVariable Refrigerant Flow optimization | Seventhwave
• Innovative aerosol envelope sealing
• Next generation Air Source Heat Pumps
• Hybrid geothermal achieves highest performance
33. Results and Recommendations
seventhwave.org/dcv
• Most room for improvement was found in
basic design
• Proper commissioning (or recommissioning)
has a significant impact on its performance
• Identifed four key program
opportunities
36. Research Approach
o What should the mechanical room setpoint be?
o How to operate louvers?
o Should supplemental heating be natural gas or electric?
o What is the optimal defrost strategy?
o How to handle condensate from supplemental heater?
Energy Balance Energy Consumption
1. Outdoor units
• heating and/or cooling
2. Supplemental heating
3. Auxiliary heating
• baseboard
4. Mechanical room
ventilation fan
37. Results and Recommendations
Optimal
The optimal mechanical room
setpoint occurs at a temperature
close to, but higher than, the
temperature at which the VRF
system’s heating efficiency and
capacity are significantly
reduced.
o Supplemental heating should be provided by natural gas.
o Demand defrost saves 4% of VRF energy as compared
to timed defrost.
seventhwave.org/cold-climate-vrf
38. Today’s Round-Up
• Commissioning for daylighting controls
• Optimizing operation of buildings with indoor pools
• Energy Recovery Ventilation effectiveness
• Maximizing energy savings from Demand Control Ventilation
• Cold-Climate Variable Refrigerant Flow optimization
• Innovative aerosol envelope sealing | CEE
• Next generation Air Source Heat Pumps | CEE
• Hybrid geothermal achieves highest performance
39. Pg. 39
Aerosol Sealing
A new building envelope technology for
renovation & new construction projects
Dave Bohac P.E. | Director of Research
Minnesota Conservation Applied Research
and Development (CARD) Grant Program
Partners
40. Pg. 40
Multifamily Aerosol Sealing
Why we took a look
• Proven duct sealing technology. UC Davis/WCEC performed lab tests
and limited demonstration for envelope sealing
Research Objective
• Demonstrate leakage reduction in multifamily buildings and refine sealing
protocol
Extent of Data Collected
• Sealed 16 units in 3 new construction buildings
• Sealed 9 units in 3 existing buildings
• Modeled energy savings and air flow impacts
Conducted
Jan 2014 – July 2016
Aerosol Envelope Sealing of Multifamily Buildings
41. Pg. 41
Aerosol Envelope Sealing –
How Does it Do That?
• Pressurize apartment
• Spray air sealing fog
Aerosol Envelope Sealing of Multifamily Buildings
42. Pg. 42
Air Sealing Results: New Construction
Aerosol Envelope Sealing of Multifamily Buildings
• Average leakage reduction of 81%
• Average leakage = 0.7 ACH50 after sealing
• All units at least 80% tighter than EPA ENERGY STAR
requirement of 0.3 CFM50/sf
• Half of the units met 0.6 ACH50 passive house
standard
• 69 therms/yr savings (3 to 0.6ACH50 reduction)
43. Pg. 43
What Gets Sealed?
Aerosol Envelope Sealing of Multifamily Buildings
44. Pg. 44
What Gets Sealed?
Aerosol Envelope Sealing of Multifamily Buildings
45. Pg. 45
Air Sealing Results: Existing Buildings
Aerosol Envelope Sealing of Multifamily Buildings
• Median leakage reduction of 75%
• Medain pre-leakage of 13.7 ACH50 reduced to 3.2
ACH50
• 60 to 200 therms/yr savings depending on existing
leakage
46. Pg. 46
Non-Energy Benefits
• Improved IAQ from reduced air transfer between units
• Reduced sound transmission between neighbors and
outdoors
• More reliable method for meeting tightness
requirements and test is part of service
Aerosol Envelope Sealing of Multifamily Buildings
Mechanical ventilation required after sealing and balanced
ventilation needed for tighter units
47. Pg. 47
Future Work
• Final report available soon
• DOE Building America: integrate sealing into new
house construction process
• WCEC – Department of Defense large building sealing
• Aeroseal has started commercial work and developing
contractor network Q4 2017
Aerosol Envelope Sealing of Multifamily Buildings
48. Pg. 48
Next generation Air Source Heat Pumps
Are the new generation of air source heat
pumps a good fit for cold climate heating?
Ben Schoenbauer | Senior Mechanical Engineer
Partner
49. Pg. 49
Field Assessment of Cold-Climate
Air Source Heat Pumps (ccASHPs)
Why we took a look
• Technological advancements have expanded the applicable climates
• Potential to serve an under-represented sector
Research Objective
• Characterize system performance and installation challenges
• Assess the implications to policy and programs
Extent of Data Collected
• Data collected in 6 homes over 2 heating seasons
Notable Previous Work
• Research and program development in “cool” climates (NE and NW)
Conducted
Jan 2015 – Aug 2017
ccASHPs
50. Pg. 50
ccASHPs in Brief
• Technology Purpose: To provide energy efficient
space conditioning through the transfer of heat between
the exterior and interior of a home
(a.k.a. an alternative primary source)
• Applications: Potential to
meet the needs of an under-
served group (homes heated
with delivered fuels or electricity)
• Expectations: 1.5x or larger
increase to space heating COP
while maintaining comfort
ccASHP
51. Pg. 51
Findings & Observations
Expectations and Concerns
• Can ASHP really transfer heat at cold outdoor conditions?
Reality from the Field
ccASHPs provide benefits down to and beyond 10 ⁰ F, including:
• COPs more than 1.5x as efficient as baseline systems
• Sufficient capacities to meet the heating loads of most MN homes
• Sufficient airflow and temperatures to condition most homes comfortably
Opportunity for the Future
• Integration with existing systems
• Initial costs
• Eliminate or minimize the need to backup
ccASHP
52. Pg. 52
Bright Spots & Opportunities
• Site energy savings
• Energy cost reductions
• Reduced reliance of delivered fuels and/or peak electricity
Benefits Beyond Energy
• Opportunities to serve in rural communities
How You Might Use this Information
• Utilities:
• Heating rebates & programs that service this technology
• Contractors:
• A signal that new gen products are appropriate in MN & guidance on
when
• Architects & Engineers:
• Consider as viable technology in all parts of MN
ccASHP
53. Today’s Round-Up
• Commissioning for daylighting controls
• Optimizing operation of buildings with indoor pools
• Energy Recovery Ventilation effectiveness
• Maximizing energy savings from Demand Control Ventilation
• Cold-Climate Variable Refrigerant Flow optimization
• Innovative aerosol envelope sealing
• Next generation Air Source Heat Pumps
• Hybrid geothermal achieves highest performance | Seventhwave
56. Background and Objective
Example system
Cooling dominated
Coupled hydronic loops
Series supplemental device
Dedicated supplemental pump
57. Research Approach
Cashman Equipment (cooling dominant)
300k ft2 equipment dealer in
Henderson, NV
East Career and Technical Academy
(cooling dominant)
250k ft2 vocational high school in Las
Vegas, NV
Tobacco Lofts (heating dominant)
74k ft2 multifamily
building in Madison, WI
58. Results and Recommendations
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
EastCTA Cashman TobaccoLofts
EnergyandWaterCost($/ft2)
Conventional HVAC
GSHP System
HybridGSHP System
….for East CTA building
$8,000,000
$9,000,000
$10,000,000
$11,000,000
$12,000,000
GSHP Hybrid Conventional
$8,000,000
$9,000,000
$10,000,000
$11,000,000
$12,000,000
GSHP Hybrid Conventional
Cooling Tower Cost
GHX Cost
Other Costs
AnnualCosts($/ft2)
59. Results and Recommendations
Adjusted Internal Rate of Return
Cashman East CTA Tobacco Lofts
Hybrid instead of Conventional 10% 12% 9%
GSHP instead of hybrid 5% 4% 1%
63. Pg. 63
Series Sneak Peak | July 2017
• Characteristics & savings opportunities for residential high energy users
• Energy saving opportunities in mobile homes
• Home HVAC install and maintenance opportunities
• Small embedded data center energy saving strategies
• Commercial energy codes support program pilot
Upcoming Deeper Dive Webinars
• Roof-top Unit Market Characterization | March 2017
• Aerosol Envelope Sealing | spring 2017
• Energy Recovery Ventilation Research Results | summer 2017
• Commercial Duct Leakage Reduction Opportunities | spring 2017
64. Pg. 64
Contacts
Dave Bohac| Director of Research
dbohac@mncee.org
Russ Landry| Sr. Mechanical Engineer
rlandry@mncee.org
Josh Quinnell| Sr. Research Engineer
jquinnell@mncee.org
Ben Schoenbauer| Sr. Research Engineer
bschoenbauer@mncee.org
Doug Ahl | Director of Research
dahl@seventhwave.org
Scott Schuetter | Sr. Energy Engineer
sschuetter@seventhwave.org
Editor's Notes
At a DOE Building America meeting a few years ago I was blown away by a presentation by Mark Modera on aerosol envelope sealing. The aerosol duct sealing technology was developed over 15 years ago. Thousands of system have been sealed by Aeroseal contractors and it is common to get leakage reductions of over 90%. The Western Cooling Efficiency Center at UC Davis has been adapting the technology to seal building envelopes. At the start of this project they had completed lab tests and a limited number of demonstration projects on houses. We initiated a project with them to demonstrate the aerosol envelope sealing process for existing and new multifamily buildings. Thru this project we sealed 16 units in 3 new construction buildings and 9 units in 3 existing buildings. All of the existing buildings were being renovated and were unoccupied. UC Davis also performed multizone air flow and building energy modeling to evaluate the impact of sealing MF buildings in Minnesota.
The process for aerosol envelope sealing is similar to that used for ducts. A blower door or duct testing fan is used to pressurize the unit to about 100Pa and multiple aerosol sprayers release a fog of sealant into the unit. As the air with the sealant flows out of leaks, some of the sealant particles attach to the edge of the leak. Over time there is a build-up of sealant and the leak is closed. The sealing takes 45 minutes to a couple of hours and will seal leaks up to 3/8” to 5/8” wide depending on how long you continue sealing. When you add in the pre-sealing of large leaks, unit prep to protect the deposition of sealant on horizontal surfaces, and the clean-up process – the total labor averaged 14 person-hours for new construction units and 22 hours for existing units. However, we expect that would be greatly reduced when contractors are applying the technology and they develop a more streamlined process.
Overall, the sealing worked incredibly well. The percent reduction ranged from 67% to 94% with an average of 81% and average post ACH50 of about 0.7.
The units were 54% to 95% tighter than new code requirement of 3.0 ACH50 (using the total leakage). The tightest unit was 25 cfm50. All of the units were at least 80% tighter than the EPA Energy Star Multifamily High Rise requirement and half of the units met the passive house standard of 0.6ACH50. They did that without even having that as a goal.
Energy modeling showed that a reduction in the exterior leakage of 3 to 0.6 ACH50 would result in space heating savings of about 69 therms/yr in Minnesota. However, for new construction it is expected that much of the cost savings will be a reduction in conventional sealing needed to produce tighter units.
These pictures show some of the leaks that are commonly sealed. You can see the gray sealant deposited around plumbing penetrations. The sealant also does a nice job sealing the small gaps around electric boxes. In fact, one of the real advantages of the aerosol sealing process is the ability to seal diffuse, small gaps that would be too costly to seal manually. While these gaps may seem small, they can add up to a big number.
For some of the units the sealant pigment was removed and fluorescing dye added so that a black light would show the build-up of sealant. These pictures show the sealant at a floor wall joint were the bottom plate had been caulked and gypcrete poured against the wall. Even in that situation, there was leakage that could be sealed with the aerosol. The picture in the upper left shows sealant around an electric box.
The sealing was also very effective for almost all of the existing units. The percent reduction ranged from 39% to 89% with an median of 75% and median post ACH50 of 3.2. The modeling showed that depending on the leakage of the existing units, the savings ranged from 60 to 200 therms per year.
We were focusing on the energy benefits of air sealing. However, there are numerous non-energy benefits for this technology. The process will not only seal leaks to the exterior but also to the interior so the movement of odors and contaminants between units will be decreased. Reducing air leakage is also key to reducing sound transmission – both between units and from the outdoors. Finally, just as aerosol duct sealing is generally more reliable than manual methods, aerosol envelope sealing is more reliable than conventional envelope sealing methods and helps reduce training and quality control process that is necessary for tight envelopes in new construction. There is also potential to save money by eliminating some of the conventional caulking and foaming of leaks.
In addition, the aerosol sealing process provides real-time feedback on tightness so that you can decide when the unit is tight enough and a test at the end of the process.
The final report will be available in the next month or two.
We are currently working with WCEC on a DOE Building America project to integrate aerosol sealing into the new home construction process to reduce conventional sealing costs and more reliably produce tighter homes.
WCEC is also working on a DoD project to apply the process to larger buildings.
Finally, Aeroseal has started to provide this service on a commercial basis and expect to start developing their contractor network by the end of the year.