field monitoring of air conditioning systems in the tertiary sector: experiences in italy marco...
TRANSCRIPT
![Page 1: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/1.jpg)
Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in ItalyMarco Masoero – Politecnico di Torino
CASE STUDIES OF AC SYSTEM ENERGY AUDIT
One of the goals of the AUDITAC project has been to collect and organise into a data base successful Case Studies of AC system energy AUDITS
The available information on such audits has proved to be limited in all participating countries, particularly as far as the actual energy consumption data are concerned
![Page 2: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/2.jpg)
PROBLEMS ENCOUNTERED (1)
The main energy input for AC systems is the electricity used by the motors that drive refrigerating compressors, fans, and pumps
Generally, electrical energy is centrally metered at the grid interface (main delivery board) without separating the individual users (i.e., lighting, appliances, AC, etc.)
Most energy service contracts include AC systems, but electricity bills are generally paid directly by the building owner / tenant
Consequently, no real reasons exist at present for implementing a costly and relatively complex procedure of gathering disaggregated electricity use data
![Page 3: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/3.jpg)
PROBLEMS ENCOUNTERED (2)
Most AC system retrofits carried out in the past (at least in Italy) were determined by reasons different from energy conservation, namely:
• Improving the comfort condition in work spaces• Solving IAQ problems, or complying with compulsory
regulations on air changes (e.g. in hospitals)• Replacing room air conditioners with a central HVAC
system to overcome maintenance problems and to avoid excessive differences in indoor environmental conditions
![Page 4: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/4.jpg)
PROBLEMS ENCOUNTERED (3)
For space heating, the Heating Degree-Day (HDD) method has been firmly established since decades as a simple and reliable means for correlating energy consumption and local climate
Standard methods for AC energy data analysis are not as well known and established in the professional community
![Page 5: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/5.jpg)
CASE STUDIES FOR ITALY
Three case studies are presented:
1. Hospital in NE Italy: air conditioning of a surgery / nursing department
2. Hospital in NW Italy: retrofits of existing refrigeration equipment
3. Water-to-water heat pump system for a small Auditorium
![Page 6: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/6.jpg)
CASE STUDY No. 1 Surgery / nursing department:
•Air-conditioned floor area 350 m2
•Two identical AHUs each with:
•9700 m3/h air supply (100% outdoor)
•8800 m3/h extraction
•Fan power: 11 kW supply, 4 kW extract
•Intermediate-fluid heat recovery
The energy analysis has been focused on optimising the operation of the
Air Handling Units
![Page 7: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/7.jpg)
Monitoring campaign data (June-September 2006):
•Electricity consumption of the heat recovery loop circulation pump
•Air and water temperatures (16 sensors)
![Page 8: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/8.jpg)
Heat Recovery data analysis:
•Measured average effectiveness of the existing recovery system: 58% (A)
•Estimated effectiveness of an air-to-air recovery system: 65% (B)
Heat recovery type A B Δ (B–A)
Recovered thermal energy (kWh) 2955 7819 4864
Chiller electrical energy savings (kWh) 1477 3910 2433
Pump electrical consumption (kWh) 389 0 -389
Net electrical energy savings (kWh) 1088 3910 2822
•Seasonal savings with existing recovery system: 300 € (A)
•Seasonal savings with air-to-air recovery system: 500 € (B)
![Page 9: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/9.jpg)
Free cooling with outdoor air:
•Free cooling by direct supply of outdoor air (without mechanical cooling) is assumed feasible when Tout < 20°C
•Estimated energy savings
Free cooling YES NO Δ Δ(%)
Cooling energy (kWh) 48075 57079 9004 16%
Chiller electrical energy (kWh) 24037 28539 4502 16%
![Page 10: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/10.jpg)
CASE STUDY No. 2
Retrofits of existing refrigeration equipment :
•No cooling foreseen at time of hospital construction (early 1960s)
•15 chillers installed were needed
•Retrofit work includes:
•New water loop connecting the units
•Two new chillers (963 kW cooling each)
Several different strategies of refrigeration units management (including
recovery of condensation heat) have been analysed
![Page 11: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/11.jpg)
Daily cost for electric energy and possible saving in the analyzed
period
-€ 10
€ 40
€ 90
€ 140
€ 190
€ 240
€ 290
€ 340
€ 390
€ 440
April
May
June
July
1-15
Aug
ust
16-3
0 A
ugus
t1-
15 S
epte
mbe
r16
-30
Sep
tem
ber
Oct
ober
Aver
age
Cos
t
Euro/Day
Obtained saving Old chillers New chillers
Partial replacement of existing chillers with the new ones
![Page 12: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/12.jpg)
Recovery of condensation heat for SHW production:
Economic analysis (Net Present Value)
NPV
-€ 16.000
-€ 14.000
-€ 12.000
-€ 10.000
-€ 8.000
-€ 6.000
-€ 4.000
-€ 2.000
€ 0
€ 2.000
€ 4.000
€ 6.000
0 1 2 3 4 5 6Years
![Page 13: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/13.jpg)
CASE STUDY No. 3
Monitoring of a water-to water heat pump for a small Auditorium:
•Air-conditioned floor area 300 m2
•Fan-coil + primary air (3200 m3/h) HVAC
•Heat Pump cooling power 68 kW @ 7-12°C
•Heat Pump heating power 60 kW @ 40-45°C
•Heat source / sink: lake water
![Page 14: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/14.jpg)
Heat Pump / HVAC System Scheme
SECONDARY CIRCUIT
AHU
FAN COIL
HEAT PUMP
TO LAKE
FROMLAKE
PRIMARY CIRCUIT
![Page 15: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/15.jpg)
BEMS
![Page 16: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/16.jpg)
Monthly average Heat Pump C.O.P. vs. outdoor temperature
Monthly average C.O.P.
0,00,51,01,52,02,53,03,54,04,5
May June July August September
0
5
10
15
20
25
30
[ °C ]
C.O.P. Outdoor temperature
![Page 17: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/17.jpg)
Cooling energy vs. air temperature, air specific humidity and air enthalpy
Supplied energy
90
110
130
150
170
190
210
20 21 22 23 24 25 26 27 28 29 30
Outdoor temperature [°C]
[ kJ /
m^3
]
Supplied energy
90
110
130
150
170
190
7 9 11 13 15
Specific humidity [ kg H2O / kg AIR ]
[ kJ
/ m^3
]
Supplied energy
90
110
130
150
170
190
35 40 45 50 55 60 65
Outdoor air enthalpy [kJ/Kg]
[ kJ /
m^3
]
Curva cumulativa del fattore di carico giornaliero
0
20
40
60
80
100
120
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7
Utilization factor
[%]
![Page 18: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/18.jpg)
Conclusions (1)The implementation of EPBD’s article 9 may offer a unique
opportunity to promote effective energy savings policies in building air conditioning
In order to transform this opportunity into a real market, several technical and institutional barriers still have to be overcome:
• National legislations must provide clear guidance on AC inspection, in terms of timing, methodologies, reference standards, official inspecting bodies , etc.
• Incentives should be adopted in order to promote energy service contracts including clauses that – similarly to what is already customary in space heating – remunerate electrical energy savings in summer air conditioning
![Page 19: Field Monitoring of Air Conditioning Systems in the Tertiary Sector: Experiences in Italy Marco Masoero – Politecnico di Torino CASE STUDIES OF AC SYSTEM](https://reader035.vdocuments.mx/reader035/viewer/2022062320/56649b5c550346318e8dc759/html5/thumbnails/19.jpg)
Conclusions (2)• Technical standards, accepted by the professional and scientific
community, are needed both for the calculation of summer AC energy and for the evaluation of ECOs
• Provisions for disaggregated electricity use metering should become customary in new installations and incentives for retrofitting the existing one should also be introduced
To overcome these barriers, a concerted action will be necessary in the coming years involving, at the Community level, more EC funded research and CEN activities, and, at the National level, an effort to complete the implementation of the EPBD to include summer air conditioning.