Whole Building Scoring Methodology
Introduction to Whole Building Scoring
The Whole Building Scoring Methodology enables Organizations to see “the needle move” as Tasks are completed by focusing on the highest impact and more important equipment. The updated methodology will show more variation in the score as new issues arise and the team actions these Tasks. The score is equally weighted across four equipment groups (or those integrated) - Air Handlers, Cooling System, Heating System, and Zone Equipment - to also see the larger impact of these critical central plant equipment that may be smaller in quantity compared to zone equipment.
See how your Organization scores in the Building Scorecard Dashboard.
Energy Score Proxy
Our Diagnostics use a sophisticated methodology to determine the energy waste and calculate the avoidable cost resulting from a fault or inefficiency. Diagnostic Avoidable Cost is thus the best proxy for calculating the energy performance of a building. A building with higher Diagnostic Avoidable Costs is performing poorer than a building with low avoidable costs and attention should be directed to faults resulting in the largest avoidable costs for savings.
Score Equipment Groups
Each piece of equipment is rolled up into one of four equipment groups: Air Handlers, Cooling System, Heating System, and Zone Equipment. Scores are then equally weighted across each of the equipment groups integrated for the site. When all equipment has been integrated, each equipment group will affect 25% of the overall score. In an example where only Air Handlers and Zone Equipment are integrated at the building, the scores from each equipment group will be 50% of the overall score. The intent is to weigh more critical equipment like chillers that are smaller in quantity than zone equipment like VAVs more heavily to see the impact overall on the score.
The four Equipment Groups are made up of the following equipment:
Air Handlers
Equipment Classes: AHU thermal element, air duct, air handler, and ventilation system
Cooling System
Equipment Classes: chiller, compressor, cooling system, dual conditioning system, and refrigerant system
Equipment Types: cooling tower open, split system cooling condenser, air cooled condenser, fluid cooler, heat exchanger free cooling, heat exchanger condenser water, heat exchanger chilled water, heat exchanger cold thermal energy storage, heat exchanger utility CHW, heat exchanger CHW pri to dual temp, and heat exchanger CHW to PW
Heating System
Equipment Classes: boiler, domestic water system, heat recovery system, and heating system
Equipment Types: geothermal well, solar thermal loop, hydrothermal loop, heat exchanger steam to HW, heat exchanger hot water, heat exchanger HW pri to DHW, heat exchanger HW sec to DHW, heat exchanger HR to HW, heat exchanger utility HW, heat exchanger HW pri to dual temp, heat exchanger steam to PW, heat exchanger CW to HW, heat exchanger steam to DHW, and heat exchanger
Zone Equipment
Equipment Classes: Fan, Lab Equipment, Zone Equipment, Zone Group
The following Equipment Classes were not included in the building score: building, compressed air system, filter, lighting system, motor, outdoor conditions, pipe, power generation, process water system, programs, pump, tank and treatment, utilities, vertical transport, and waste water system.
Maintenance Score
The Maintenance Score is calculated by taking the maximum Maintenance Priority of all the analyses on a piece of equipment, averaging that across all equipment in that equipment group, and then equally weighting all the equipment groups into a single Maintenance Score.
Here is an example starting with calculating the Maintenance Score of air handlers:
Maintenance Priorities are assigned to equipment for each Diagnostic analysis on a scale of 0 to 10 based on the severity of the issue found when the equipment is not operating as expected. For AHU 1 in this example, there are four different analyses running - AHU Coils, AHU Economizer, AHU Fan, and AHU Heat Recovery - with maintenance priorities of 2, 0, 4, and 0, respectively.
The score calculation starts at the Equipment level. The maximum maintenance priority is taken for each air handler. On AHU 1, the most severe issue is on the AHU Fan analysis with a maintenance priority of 4, thus AHU 1 gets a maximum maintenance priority of 4.
To then calculate the Maintenance Score for air handlers, the maximum maintenance priorities are averaged across all equipment in the Air Handler equipment group defined above. In this example, we average the maximum maintenance priority of AHU 1, AHU 2, and AHU 3 which are 4, 8, and 2, respectively. This is next converted to a score percentage by subtracting the average maintenance priority from the maximum possible priority of 10 and multiplying by 10. Here that computes to 53% for the Air Handler Maintenance Score.
Similarly, the Maintenance Score is calculated for each of the different equipment groups integrated to the building. Building 1 in this example has all four equipment groups so a Maintenance Score is calculated for the Zone Equipment, Air Handlers, Heating System, and Cooling System whereas in Building 2 there are only maintenance scores for the Zone Equipment and Air Handler equipment integrated in the building. The overall Building Maintenance Score is then calculated by averaging the score of these integrated equipment groups. In Building 1 each equipment group contributes to 25% of the overall Maintenance Score, while in Building 2 the two equipment groups contribute 50% to the overall score. Building 1 Maintenance Score is thus the average of 80%, 53%, 90%, and 40% from each of the equipment groups for a total score of 66%.
Finally, the Portfolio Maintenance Score is the average score across all the buildings within that Portfolio. The Portfolio Maintenance Score in this example is then 63%, or the average of Building 1 and Building 2 Maintenance Scores of 66% and 60%, respectively.
Comfort Score
The Comfort Score is calculated in the same way as the Maintenance Score, however Comfort Priorities are only calculated for Air Handler and Zone Equipment groups. Thus, the Comfort Score is equally weighted between those two equipment groups.
Here is an example starting with calculating the Comfort Score of air handlers:
Similar to the Maintenance Score, the Comfort Score is first calculated by taking the maximum comfort priority of the analyses for each piece of equipment. The maximum comfort priorities are then averaged across all the equipment in the equipment group and converted to the score. In this example, the maximum comfort priority for AHU 1 is 2 from the AHU Fan analysis. Then this is averaged with the other air handler maximum comfort priorities of 6 and 2 for AHU 2 and AHU 3, respectively. This is converted to a percentage by subtracting it from the maximum priority of 10 and multiplying by 10 for a total of 67%.
Here the Comfort Score is only calculated from the Zone Equipment and Air Handler equipment groups so in both Building 1 and Building 2 the Comfort Score is the average of the two equipment group scores. The Portfolio Comfort Score is then the average Comfort Score of all the buildings for a score of 71% in this example.