Research carried out by the group's employees in sales and installation of air conditioning in Muang district of NakhonPathom. NakhonPathom, 12 stores were used in this research was questionnaire about management practices survey before installing air conditioning. The questionnaire is divided into two parts, sales and service. When the data were taken with the achievement of percentage points of the average (x ̅) and the standard deviation (SD) findings from the sales. Percentage points as a percentage of average at 98.75 (x ̅ = 39.5) and the standard deviation (SD = 0.916), respectively, which is at the highest level. The service department is the percentage of the full score as a percentage 97.45 average (x ̅ = 82.833) and the standard deviation (SD = 4.337), respectively, which is at the highest level, so sentiment survey. Sales and Service at 0.622 and 0.504, The confidence of the two Department questionnaire that has the confidence moderate level.