When it comes down to choosing the correct laboratory water system, you need to consider the following aspects:
1) What type or types of lab water do I need?
2) How much lab water do I need per day / per week?
3) What are the peak volume of lab water usage?
4) How much space is available?
What type or types of lab water do I need?
To answer this question, you need to have a look at your applications. Often the required water quality is defined in the user manuals in case of the instruments for analytical applications (like HPLC, ICP, AA,…) or general purposes (autoclaves, water baths,…) or it is well described in literature.
Useful articles to read:
What water type is used for different laboratory applications?
What are the different laboratory water types?
How much lab water do I need per day?
Fur Type I (Ultrapure) water, the used volume is generally low, and this is typically produced at 2l/min dispensing rate on demand to guarantee type I quality. Type II (pure) water and Type III (RO water) on the other hand are typically produced and temporary stored in a tank before usage. To evaluate the required production rate for the instrument and the tank volume for storage, it is important to know your maximum daily usage. Also keep in mind that benchtop systems are not made to run 24h.
What is the peak volume of lab water usage?
This is also relevant for the choice of the production rate and tank volume of the lab water system. This is mainly important for the production volume and tank volume. Keep in mind that for example most laboratory dishwasher programs use around 19l (and some programs up to 28l or even 45l) in a very short timeframe.
How much space is available?
Water purification systems come in different sizes. Typically the larger the production rate, the larger the unit. It is always important to check where to place the units. Some systems are benchtop. Often benchtop systems can be wall-mounted, or placed in a bench, depending on the model. Also consider the tank. Small tanks often can be wall-mounted, or placed under the bench as well. Sometimes, it is more interesting to combine multiple smaller production units, or multiple smaller tanks instead of one. In some cases, the production unit can be integrated together with the tank and other components in an undercounter system to fit under a bench. Central systems on the other hand often come in cabinets that are free-standing on the floor.