Table 2.

Airflow exchange rate calculations by vault

Machine vault	Measurement∗	Airflow exchange per hour	t99% (min)	t99.9% (min)
Primary campus
Standard LINAC 1	Actual	10.07	27.72	41.14
Standard LINAC 2	Actual	5.94	46.53	69.97
Standard LINAC 3	Actual	5.83	47.39	71.30
Tomotherapy	Actual	16.99	16.60	24.31
Specialty stereotactic	Actual	7.63	36.40	54.39
Regional campus 1
All standard LINACs	Minimum	12	23.34	34.49
	Maximum	18	15.68	22.94
Tomotherapy	Minimum	10	27.91	41.43
	Maximum	15	18.75	27.55
All proton gantries	Minimum	6	46.07	69.26
	Maximum	12	23.34	34.49
Regional campus 2
Standard LINAC	Actual	6.5	42.59	63.91
Regional campus 3
Standard LINAC	Actual	8	34.74	51.86
Regional campus 4
Standard LINAC	Actual	6.5	42.59	63.91

Abbreviations: LINAC = linear accelerator; t99% = time for 99% airflow exchange; t99.9% = time for full (99.9%) airflow exchange.

^∗Actual measurements represent airflow measured under standard automatic temperature control and building automation systems settings. Minimum and maximum measurements represent the range of airflow rates delineated according room design specifications; these were not directly measured.