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04/20/23 1
Unlocking the Secrets of HVAC
Nash-Rocky Mount Public Schools
04/20/23 2
Overcoming Obstacles and Barriers
• Have you heard this before ?
– We need to run the school all night to heat the building!
– The energy program will cause us to have additional complaints or problems!
– Its always been that way! Just ask Bubba!!• Maybe it’s time for a change!
04/20/23 3
Understanding HVAC
• Where do you start?– Your biggest user?, or highest KBTU per sq.ft.
rating in Portfolio Manager? Look at 50% to 75%.– Improve the comfort level for energy savings.
• Who can help? – ANYONE! -- Energy Consultants, Engineers,
mechanics, directors, teaching staff, vendors.• Are you a detective?
– Did you ask all of the simple or right questions ?
Understanding Your Current Energy Use
• Benchmarking through ENERGY STAR’s (EPA’s) Portfolio Manager allows you to:
– Compare one building against a national sample of similar buildings
– Compare all of your buildings of a similar type to each other
– Set priorities for use of limited staff time and/or investment capital
Portfolio Manager• Benchmark the energy use of all of your buildings –
receive an energy use intensity (EUI) and K-12 schools and office buildings can receive energy performance ratings on a 1-100 scale
• Track changes in energy use over time in single buildings, groups of buildings, or entire portfolios
• Track cost savings and CO2 emissions• Apply for the ENERGY STAR• Track water usage
Understanding Your Current Energy Use
http://www.energystar.gov/benchmark
OfficesK-12 Schools
HotelsSupermarkets
Hospitals
Retail Stores
Others include: Warehouse, Residence Halls, Courthouses, Medical Offices,
Financial Centers/Banks, and Wastewater Treatment Plants
Ratable Spaces in Ratable Spaces in Portfolio ManagerPortfolio Manager
ENERGY STAR for Buildings• ENERGY STAR qualified buildings use 35 percent
less energy than average buildings. • Nearly 5,500 buildings, including more than 1,100
K-12 schools, have earned the ENERGY STAR for energy efficiency.
Red Oak Middle Nashville Elem
04/20/23 8
Areas to look for savings
• Mechanical
– AHU’s
–Central Plant
–Heat Pumps
• DDC Software Logic
04/20/23 9
All the Pieces
• Do You have the missing piece of the puzzle?
• You must have equipment working correctly, time clocks working, and DDC Sequence of Operation correct.
Reports
PM
Data Loggers
?Filters
Energy Projects
Boilers
ChillersHeat
Pumps
04/20/23 10
HVAC Terms
• DDC – Direct Digital Control System– Lead/Lag, RH, CWS, HWS, OAT, Outdoor Temp
Resets, OSS Blocks, CSP, HSP SPC Temp
• Mechanical– AHU, Primary/Secondary Loop, Mixing Valve, Split
System, SEER, PM’s, Central Plant
04/20/23 11
Findings using Data Logging as a Tool
04/20/23 12
Mechanical
• AHU’s
– How often do units have PM’s performed?
• Filters, Belts, motors/pulleys, coils cleaned, valves, actuators, and circuit setters.
• Have you checked the H/W C/W Strainers, and are they clean?
04/20/23 13
Mechanical
• Central Plant– How often do Boilers, Chillers, Cooling Towers,
Heat Exchangers, and Pumps have PM’s performed and cleaned?
• Heat Pumps – How often do units have PM’s performed? – Filters, Belts, motors/pulleys, coils cleaned,
refrigerant checked
04/20/23 14
DDC Systems
• How long has it been since it was installed?– If over two or three years consider re-commissioning
the system.– Have you updated system logic to the best energy
efficient strategies?– The NC Energy Office will help pay for DDC Tune-
ups.
04/20/23 15
DDC Systems
• Problem 1 – The zone temps do not look the same as occupied / unoccupied times. – Johnson Control’s N-30, check your date, clock, and
UTC offset. For Eastern Standard Time it should be 300.
• Problem 2 – The building seems to start up too early.– Siebe / Barber Colman Network 8000, check your
site time and OSS block maximum start time.
04/20/23 16
DDC Systems
• Problem 3 – The zone temps are reported too cold during the day in the winter mode, but ok when mechanic arrives. (Is it the teacher ?)– Siebe / Barber Colman Network 8000, check your
default time and default set-point values. They should be slightly higher on cool or slightly lower on heat.
04/20/23 17
DDC Systems
• Logic– Do water source Heat Pumps start before system loop
is at operating temps?– Do you have more than one schedule for your site, and
if so, do you stage their start time?– Do you use Optimum Start/Stop and if so what is the
maximum start/stop allowed?– Do you have OA Temperature Resets to control
Building loop Temperature? (30-60 180-140)
04/20/23 18
Results using Data Logging as a Tool
04/20/23 19
Reporting as a Tool
Energy Use Graph - Monthly and Annual Trend for Nash Rocky MountSchools
Electricity Fossil Fuels Annual Trend
MB
TU
09/2003 thru 12/2007
0
5,000
10,000
15,000
20,000
25,000
09/03 12/03 03/04 06/04 09/04 12/04 03/05 06/05 09/05 12/05 03/06 06/06 09/06 12/06 03/07 06/07 09/07 12/07
04/20/23 20
Results of NRMPS Energy Program
• First Four Years– KHW Saved ---------------- 26,142,085– Cost Avoidance Savings -- $4,372,979
• The check that you don’t write
– Hard Dollars ------------------ $258,649• Money in the bank
– Billing errors found ---------- $180,655• Monitoring of your bills
04/20/23 21
Environmental Impact
The avoided emissions of 18,602 metric tons of Carbon Dioxide or:
Greenhouse emissions from 3407 automobilesCO2 emissions from 2,111,518 gals of gas consumedCO2 emissions from the electricity use of 2464 homes
for one yearCarbon sequestered annually by 4,228 acres of pine
forest
04/20/23 22
• Our program was started on 9/1/04.– By 12/31/06 we had 13 ENERGY STAR labeled
buildings.– By 11/15/07 we have 18 additional Energy Stars.– By 10/24/08 we have 20 additional Energy Stars.– This will bring our total to 51 awards at 22 different
sites.
ENERGY STAR Ratings
04/20/23 23
Summary
• Do you have an energy program?
• How is your HVAC maintained?
• Is your DDC system out of site, out of mind?
• Who monitors utility bills, usage, reporting, and troubleshooting?
04/20/23 24
Where to Get More Information
• www.educonenergy.com
• www.energystar.gov
• www.energync.net
• www.advancedenergy.org
• www.southface.org