Mechanical, electrical and plumbing systems represent a large fraction of building development costs. However, smart design decisions can make these installations less expensive without reducing their performance. In fact, performance enhancements can often be achieved simultaneously with cost reductions.

Some MEP components like chillers and boilers are expensive individually, but their cost can be optimized with a single design decision - selecting equipment of the right capacity according to your building load. On the other hand, piping and duct systems connected to MEP equipment have a low cost per foot, but considerable expenses add up if you consider an entire building.

With any building system that uses pipes or air ducts, there is an opportunity to achieve savings by optimizing the layout. Ideally, you should achieve full building coverage with the lowest possible length of piping and ductwork. The same principle applies for electrical installations, where circuit travels in conduit and other types of raceway.

Optimize the cost of your MEP installations.

The easiest way to optimize piping, ductwork and conduit cost is by hiring a qualified MEP engineering firm to design your project.

Reducing the Total Length of Piping

The most common use of piping in buildings is delivering potable water and collecting wastewater. However, piping also has applications in fire protection systems and HVAC, and the following are two examples:

• Automatic sprinkler systems use piping to deliver water for every sprinkler head. Fire protection piping is normally painted red.
• Many HVAC system configurations include hydronic piping, using water to deliver or remove heat from indoor areas. For instance, a chiller does not cool the air directly; it cools water, and piping carries the chilled water to cooling coils in air handling units.

The total piping length required for a building can be reduced significantly with a smart placement of equipment and mechanical rooms. The opposite also applies: poor equipment locations lead to excessively long piping runs, which are much more expensive.

The piping costs of automatic sprinkler systems can also be reduced with an optimal layout. Ideally, your installation should use the smallest number of sprinkler heads that provides full coverage for the building.

• New constructions offer an excellent chance to optimize coverage, since fire protection engineers can work closely with the architect as the building is being designed.
• Optimization is also possible in existing constructions, but fire protection designs must adapt to the existing architectural features.

Consider that water loses pressure as it flows through piping, due to the friction between the moving fluid and the interior pipe surface. Friction losses are increased when the piping system is too long, which leads to higher pumping costs and electricity expenses.

Optimizing Air Duct Coverage

Ductwork normally shares the space above a ceiling with other MEP components. Air ducts are bulkier than piping, and layout optimization not only achieves cost reductions, but also space savings. When air ducts are selected properly, you also minimize noise and vibration issues.

Just like longer piping drives up pumping expenses, longer air ducts lead to an increase in fan power. Since Northeast states like New York and New Jersey have kilowatt-hour prices above the US average, pumping and ventilation losses have a notable effect on your power bills.

Electrical Wiring and Conduit Savings

Electrical design also provides many opportunities for layout optimization. Just like with piping and ductwork, smart equipment placement leads to shorter circuit runs. However, in the case of electrical installations, it is also possible to reduce wiring and conduit costs with energy efficiency.

• Energy efficiency reduces the power consumption of an electrical installation. Since the supply voltage is constant, this is reflected as a current reduction.
• Lower current allows the use of smaller conductors with a lower cost per foot.
• In turn, smaller conductors fit in smaller conduit, which is also cheaper.

If you are using energy efficiency measures in an existing building, there is no need to reduce circuit capacities. Oversizing causes extra expenses in new constructions and major renovations; however, when an existing circuit is already oversized, the cheapest option is simply leaving it in place.

Although the savings from downsizing an individual circuit are normally small, the cumulative effect is significant for a large building, especially when selecting electric service equipment. The cost difference is not much between 30 feet of #12 and #10 wiring, but a 500 kVA transformer is significantly cheaper than a 750 kVA unit.

Conclusion

The total ownership cost of a building can be reduced drastically with smart decisions during the design phase. Significant savings can be achieved in ductwork, piping and wiring by optimizing the layout of MEP installations. Design services from professional engineers can be considered an investment, since they reduce building ownership costs.