Assignment A6
HVAC SELECTION
Below is an explanation of the criteria matrix used to evaluate different locations and sizes for the construction of a Computer Server Farm.
Criteria Matrix
There are total twelve criteria which are used to evaluate six different HVAC systems. All of these systems are capable of air-conditioning the space, since the biggest concern of the computer server farm is the heat generated by the machines inside the room.
The Logic
Since there are five locations and 3 room sizes to select, therefore there will be a total of 15 combinations to choose from. Each combination was assigned a name from 1 – 15.
Also, a rating for each of the fifteen systems was decided to show how preferable each system is for each criteria. For example, table below shows the rating of a CAV system for the fifteen scenarios.
After the owner chooses the location and size of the building, the rating of each criteria to each HVAC system will show up in the table. To accomplish this step, the “hlookup” function was used to find each value in the tables.
Here is an example of the “hlookup” function used:
=HLOOKUP(Sheet2!$H$21,Sheet1!$D$2:$R$14,Sheet2!$E4,FALSE)
After the owner assigns the importance factor to each criteria, the matrix will add up all the “values”. Furthermore, the ratio of owner’s weight and our weight was assigned. The full value was calculated under the importance factor assigned by the owner to get the percentage of each system.
Here is the function used in excel to calculate the percentage of each system:
=($C$7*SUMPRODUCT($D$9:$D$20,E9:E20)+$D$7*SUMPRODUCT($C$9:$C$20,E9:E20))/($C$7*SUM($D$9:$D$20)+$D$7*SUM($C$9:$C$20))/5
The final step is to pick the best system for the specific location and size.
=IF(E21=MAX(E21:J21),E8,IF(F21=MAX(E21:J21),F8,IF(G21=MAX(E21:J21),G8,IF(H21=MAX(E21:J21),H8,IF(I21=MAX(E21:J21),I8,IF(J21=MAX(E21:J21),J8," "))))))
The Matrix
Owners can use our matrix to change the location of the building as well as the size. In addition, the owner has the ability to determine the importance of each criteria specified in the matrix.