There is no doubt that BMS (building management systems) or BAS (building automation systems) benefit the building industry. They increase staff productivity, help keep occupants comfortable, and provide better remote access capabilities. For building owners who see the value and have the initial capital to implement a BMS during new construction, I applaud you, as there are many benefits.
However, with a digital sensor installed on every piece of equipment, you still need redundancy. Manual analog devices allow for cross verification of digital pressures, temperatures, levels, and meter readings. This redundancy can be extremely valuable if sensors go out of calibration or need replacement. Upper management often doesn’t understand this expensive and unexpected scenario. They assume that if there’s a BMS in the building or plant that everything is being monitored. Not true.
Setting up and commissioning these mechanical systems is often the most expensive and time consuming component of implementing a BMS. During the original design review, the jaded term of “value engineering” gets tossed around over and over to save money. Through this process, only the most important equipment gets sensors installed (that means not every device is monitored or has redundancy). This leads to situations where things get neglected.
Some examples of areas often overlooked:
- The differential pressure across the plate and frame heat exchanger that requires cleaning once every three years.
- The small meter that provides make-up water to the cooling tower.
- The lack of a meter to monitor the water that can potentially be lost in a sprinkler and standpipe system.
- Whether or not outside air dampers are opened or closed.
On top of that, there are some things that a BMS will never be able to tell you, even if you put sensors on all of your equipment. Relying on your BMS/BAS alone, how would you be able to identify things like:
- Small puddles due to leaks that spring up in non-traditional areas,
- Biofouling that may be occurring in your cooling towers,
- Items obstructing dampers or vents,
- Motorized dampers not connected to the shaft, etc.
These visual inspections are things that most BMS systems can’t identify but humans can.
As much as technology is helping our buildings, always remember that people are also needed. And they deserve our respect for all they do. So please, use a BMS. It’ll help your building run better, but nothing will ever replace an analog gauge and a trained engineer/operator. To all the decision makers: Please keep this in mind during your decision-making processes.