For smaller residential properties running on the city supply, water pressure is rarely an issue. The typical home requires about 50psi at the inlet, which many municipal systems can provide without a problem. This water pressure level is sufficient for most one- or two-story homes, but commercial properties can be much larger and much taller.
Water pressure falls off in any building as you move into higher floors. For short buildings, the pressure loss is usually minor enough to go unnoticed by occupants. In buildings with three or more stories, supplying sufficient pressure to the upper levels requires extra steps. If you manage a tall commercial property, then here are three things you need to know about your commercial plumbing.
1. How Do You Supply Pressure to the Upper Floors?
Before you can understand water pressure issues in your commercial building, you need to know how its plumbing supplies water to each floor. There are two common strategies for providing water to the upper stories: boosting pressure from the lower floors or pumping water to high (usually roof-mounted) tanks. Some buildings may use a combination of both approaches.
Both strategies introduce their challenges and require specific design considerations. With roof-mounted, gravity-fed systems, you will often need pressure-reducing valves (PRVs) on the lower levels. On the other hand, booster pumps can result in too much pressure for lower-level occupants. In either case, the system designer must carefully control pressure to keep the system safe and reliable.
2. Is Your Plumbing Pressure Rated?
Different types of pipes offer different pressure rating levels. Pushing too much pressure through a line can cause it to wear out more quickly or even fail catastrophically. Depending on your structure's design, you likely have pipes rated for a variety of different pressures throughout the building. For example, designers often install lower-pressure pipes downstream from PRVs.
Understanding the tolerances in your building can help you to recognize the dangers posed by some failures. While a failing booster may supply inadequate pressure to upper levels, a faulty PRV can potentially allow high-pressure water to enter low-pressure pipes. This type of failure can cause significant damage or even pose a safety hazard.
3. Do You Have Multiple Demand Areas?
Finally, consider your building's water demand. Most commercial structures that utilize booster pumps have separate hot and cold water systems. If water demand between the two systems is uneven, then you can potentially end up in situations where upper floors "run out" of hot or cold water due entirely to pressure issues.
Since multi-story commercial buildings require sophisticated plumbing systems, it's crucial to always consult with an expert when dealing with any water pressure issue. Selecting an experienced commercial plumber will ensure that your building can continue to supply safe and reliable water pressure to its occupants.