Do manufacturers need AHUs for the quality control laboratory, or can they use office type air conditioning systems?

Yes, we do need AHUs for Laboratories or any Pharmaceutical based applications as these require precise Moisture control ( Relative Humidity Control ) and Air Filtration ( ppm - parts per million ) along with Regular Temperature control.

Commercial Air conditioners are designed for40-60% range of relative humidity,18-26 Deg C Temperature Range with basic filtration of10 Microns Filter which is suitable only for General Applications ( Offices, Residential  etc ) as they require only comfort air-conditioning.

Whereas AHUs can be customized in many aspects such as ADP ( Apparatus dew point ), No. of Rows of Evaporator Coils, Blower capacity, Filtration Levels etc  which helps to achieve more precise humidity control and Air Filtration Levels which is essential for Pharmaceutical/Lab/Industrial Applications as in these applications like medicines, printing press dyes, operation theaters etc specific Humidity and Air Filtration levels need to be maintained along with just Temperature of the space. 

Hope this answers the question.