audits and inspections in hvac auditorias e...
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Audits and inspections in HVAC
Auditorias e inspecções aos sistemas de
AVAC
Porto , 17th February 2010
J. L. Alexandre – DEMec/FEUP
DemSSo - Segurança e Saúde Ocupacionais
FEUP – Faculdade de Engenharia da Universidade do Porto
Europe per capita CO2 emissions in 2006
Reductions needed in Europe could be ~ 80% [Average during
century] - Energy efficiency and reduction of energy consumption
Some Numbers Energy Use by Sector
1999
32%
38%
13%
9%
8%indústria
transportes
doméstico
serviços
outros
Transportes
35%
Serviços
13%
Agricultura
2%
Residencial
17%
Industria
33%
2005
Portugal
Europe
5
The air conditioned surface in Europe:
estimation of the stock to 2020 from EECCACCOOLED AREA IN Mm2
0
500
1000
1500
2000
2500,
3000,
Stock 1990 Stock 1995 Stock 2000 Stock 2005 Stock 2010 Stock 2015 Stock 2020
RAC
RooftopsPACK & Large Split
VRF
Chillers
COOLED AREA IN Mm2
0
500
1000
1500
2000
2500,
3000,
Stock 1990 Stock 1995 Stock 2000 Stock 2005 Stock 2010 Stock 2015 Stock 2020
COOLED AREA IN Mm2
0
500
1000
1500
2000
2500,
3000,
Stock 1990 Stock 1995 Stock 2000 Stock 2005 Stock 2010 Stock 2015 Stock 2020
RAC
RooftopsPACK & Large Split
VRF
Chillers
RAC
RooftopsPACK & Large Split
VRF
Chillers
6
Introduction
• In Europe more than 40% total energy is used in building
sector .The sector is expanding, which is bound to
increase its energy consumption .
• New challenger demands reduction up to 20% in the next
20 years (3 x 20). In 2020, 20% energy reduction and
less 20% of gas emissions)
• Europe adopted new directives to implement the
reduction target in building sectors (tertiary and
residential sector) – EPBD [ Energy performance in Building Directive]
– Directive 2002/91/EC and
– the new recast – Directive 2010/31/EU
• Inspections and Audits of HVAC is part of the solution –
Energy management
Energy Audit Types according the HarmonAC
AUDITAC EP
• Pre-inspection
– Walk - through audit
– Analysis of utility bills
• Inspection
– Standard audit
• Audit
– detailed Audit - mainly in the AC system
Pre-inspection
Visit the facility to determine the important systems that use energy sources.
Identify and assess maintenance and operation strategies that do not require high investment.
Pre-inspection
(Analysis of Utility Bills)
Collect all utility bills (electricity, fuel, water, steam,
etc.)
Analyze the variations of the utility bills over several
years or periods
Identify other favorable utility rate structures available
for the facility
Verify if the utility costs are calculated correctly
Inspection - General Procedure
Collect all relevant data related to the facility
(construction details, retrofits, etc.)
Visit the facility
Develop a base-case for the facility
Identify and evaluate measures to save energy
cost and/or improve comfort
Classify the measures using an economic
analysis
Inspection methodology: general
AC Equipments
The introduction of the standard contains:
Instructions for measurements method, calibrated
measurement instruments
SIZE NEEDS
Compare the installed cooling capacity
to the estimated cooling needs
Estimate Specific Fan Power (standards
EN 12599 and EN 13779)
Inspection Methodology
• Inspect refrigeration equipment• Inspect for effectiveness of outdoor heat rejection• Inspect for effectiveness of heat exchange to the
refrigeration system (indoor units of split and distributed systems)
• Inspect cooled air, and independent ventilation air, delivery systems in treated spaces
• Inspect cooled air, and independent ventilation air, delivery systems at air handling units and associated ductwork
• Inspect cooled air, and independent ventilation air, delivery systems at outdoor air inlets
• Inspect building system controls and control parameters
• Energy consumption metering• Reporting
Advice on alternative solutions and improvements
Significant opportunities to reduce cooling loads (low cost improvements )
Improvements/renovation
Or replacement!
:
Cooling load reduction
Alternative cooling
techniques
CLIMACHECK
Refrigerant fluid temperature at different points of the chiller / heat pump
0
10
20
30
40
50
6015:04:50
15:06:40
15:08:30
15:10:20
15:12:10
15:14:00
15:15:50
15:17:40
15:19:30
15:21:20
15:23:10
15:25:00
15:26:50
15:28:40
15:30:30
15:32:20
15:34:10
15:36:00
15:37:50
15:39:40
15:41:30
15:43:20
15:45:10
15:47:00
15:48:50
15:50:40
15:52:30
15:54:20
15:56:10
15:58:00
15:59:50
°C
Comp1_OUT
Comp1_IN
Cond1_OUT
Comp2_IN
Comp2_OUT
Cond_W_IN
Cond_W_OUT
Cond2_OUT
19Easy to implement actions, no need
for detailed audit, Operational
Checking the
envelope use and
structure
Visual inspect the
plant
Check for the
presence of O&M
activities and
contract
Activating the
detailed audit tasks
Considering a list of
energy conservation
opportunities (ECOs)
Actions taking
place during
preliminary audit
Reduce internal loads
Improve insulation
Add solar shading
Install BEMS
Change the setpoint
temperatures
Calculate the savings from
load reduction through
replacement with
EnergyStar facilities
Use better filters
Optimise the filter
replacement frequency
Feasibility,
need for
details
Yes No
Yes No
Yes No
Yes No
Yes No
Yes No
Yes No
Assess the investment
for envelope changes
Calculate the
investment
Asses the impact on
solar loads reduction
Calculate the best
investment with savings
©JLA - FEUP
General Procedure
(Detailed Audit)
Perform the same tasks outlined for the
standard audit
Establish a base-case for the facility thermal
systems using a simulation program (DOE-2,
TRNSYS, Energy +, Energy 10, ESP-r, etc)
Monitor energy consumption by end-uses of
the facility (lighting, plug-load, cooling plant,
etc.)
IAQ requirements
energy breakdown to know where we can
actuate to reduce the energy consumptions
Inspection an Audits
• What is the best way to produce energy audits and inspection
efficiently and quickly, of course and safety?
• Many methodologies are based on CEN Standard EN 15240 and
CIBSE TM44 – we need harmonization to produce standards
• Methodology based on Field Trials and real case studies Case
Studies
Results
• Some substantial savings (up to 60%) appear available to be identified by
inspection.
• An Inspection of an A/C system would appear to take between 5 hours to
over 2.5 days on average.
Working in Progress:
- Energy survey in real cases
- Indirect methods for chillers energy efficiency analysis
Final Results of European Project
• Last 3 years 400 HVAC inspections and audits was made
around the Europe and the results were:
• The total of energy savings for all inspections and audits
was 37.9 to 112.2kWh/m2
• i.e ± 16.2Mtoe (±11% of total energy used in tertiary
building sector), which is equivalent to avoid the
emission of 62.9Mt of CO2 emissions per year. 22