To the untrained eye, swimming pool design may seem limited to the obvious, visual items: pool structure, spray features, waterslides, etc. While these items are certainly important, the true ‘meat and bones’ of a swimming pool is contained within the mechanical room. Pool mechanical rooms house the pumps, filters, heaters, chemical treatment systems, secondary disinfection 
systems, and many other items that are vital to the operation of a swimming pool. The proper design of a pool mechanical room can drastically improve operations and ultimately extend the life of the facility.
Undersized mechanical rooms are the most common problem we see in preliminary pool design. As mentioned above, the entire pool recirculation system, including all equipment and hundreds of feet of piping, is housed within the mechanical room. Each piece of equipment must be strategically placed to provide ample space for day-to-day operation and routine maintenance. Local codes and manufacturer guidelines also play a large role in dictating where equipment can be placed and how much surrounding “open” space must be provided. As a general rule of thumb, the mechanical space should be about an eighth of the size of the pool water surface area. While a good starting point, this number can greatly fluctuate depending on the project type and size. For instance, smaller pools typically require mechanical spaces twice the size of the pool surface area. In addition to the pool size, the type and quantity of pool equipment may greatly affect the proper mechanical room space that is needed.
While it may appear that pool mechanical rooms are a congested jumble of piping and equipment, in actuality, these are typically well thought out spaces. Often times when designing the layout and configuration of a mechanical room, it is best to imagine the path that pool water takes as it makes its way through the room. As the pool water first enters the mechanical room, it will pass through the hair and lint strainer before making its way to the recirculation pump. It is common practice in the commercial pool industry to house the pool pumps in a recessed pit to allow for the use of flooded suction pumps. From there, the water will travel to the filtering system, secondary disinfection system (if provided), heating system, and finally to the chemical injection points before returning to the pool. In order to avoid extra piping, fittings, and potentially larger pumps, it is important to layout the pool equipment in an efficient manner that does not require the piping to loop back and forth while inside the mechanical room.
Early on in the design phase, measures can be taken to assist the future pool operator with day-to-day operations and routine maintenance inside the mechanical room. First and foremost, a work
station should be provided near the pool’s chemical controller. This work station, generally comprised of a small table and a chair, is typically where the operator will test the chemical makeup of the pool water. In an effort to assist with general cleaning of the mechanical room, it is good practice to design for concrete housekeeping pads underneath the filters, heaters, pumps, and any other large piece of equipment. Keep in mind, many of these items will likely need to be replaced from time to time so it is crucial to plan ahead for these events. At least one set of double doors providing access into the mechanical room should be provided for the replacement of the pool filters. To assist with removal of the pumps, it is recommended that a steel beam and hoist system is provided above the pump pit. Additionally, designing for removable railings around the pump pit will make for an easier pump replacement when the time comes.
Finally, when it comes to pool chemicals, special attention and extra precautions must be taken. The pool chemicals can be the most dangerous items in the mechanical room if not properly cared for. While typically not required by code, it is highly recommended to store pool chemicals in separate, well ventilated rooms. If not properly exhausted, acid and chlorine fumes will attack and corrode nearby metallic items. When combined, the fumes can create chlorine gas which is potentially be lethal to humans. To avoid mixing of chemical fumes, each of the chemical rooms should be separately exhausted to the exterior. It is important to note that both chlorine and acid fumes are heavier than air, therefore, these fumes must be removed from a low point in each of the rooms. In addition to mechanical ventilation, each of the chemical rooms are typically required to be fire rated. The quantities and types of the pool chemicals used will dictate the extent of the fire rating that is required by code. During the design phase, it is critical to check the local building and fire codes to ensure compliance.