There are many options that seem to produce a similar result for the end users. How do you decide, for example, which mechanical system is best?

Doug: We have to juggle a number of factors when recommending a system. These include the location of the building, occupant load, construction budget, sustainability goals, and ownership, to name a few. Our recommendations can also be greatly influenced by the tenant lease agreements. We see underfloor air distribution (UFAD) appearing in many office buildings because that is what the tenant is asking for. Overall, however, we believe it’s important to keep an open mind when formulating our recommendation, as there are often alternative systems that can be just as effective, if not more.

It is also becoming more common for office buildings to target LEED platinum as a way of standing out in a competitive market for tenants. This leads us to a much more detailed review of options, which can result in high performance variable air volume systems, deep lake cooling systems with peaking chillers, and reusing chilled water return within the building as a supplementary condenser system for tenants. The decision is always informed with results from the energy model. We have used chilled beams on the interior and variable flow, non-condensing fan coil units on the perimeter spaces with a dedicated outdoor air system (DOAS) – an approach which has proven to reduce costs and mechanical space demands while providing very good ventilation in an extremely energy-efficient manner.

What about electricity? It hasn’t changed since the time of Benjamin Franklin! What major developments do you see on the electrical side of office development?

David: True, electricity itself has not changed, but S+A’s approach to electrical systems keeps evolving. Likely the most significant evolution is the growth of IP devices, a shift that is having a curious impact on a building’s electrical infrastructure. As demands for IP-based systems grow, so too does the reliance on uninterruptible power supply (UPS) and emergency power systems – all power systems, in fact. And as the “building network” that connects all these IP devices becomes more critical than ever before, the power systems that support it (and all those devices) take on an even greater role. This means that the power supply must provide more stability and reliability – a lot more – than in previous generations of building designs.

To illustrate how quickly times are changing, it was not so long ago that the industry treated these building networks as an afterthought. Mechanical and electrical systems would be put in place, and then at the very last stage of construction, the building network would be installed. In future, this will be reversed, with the building network being one of the first systems installed after the concrete has cured. That way, the system will already be up and running to serve the wide variety of IP-based equipment installed by the mechanical, electrical and general contractors. Everything from air handlers and light fixtures to security systems and elevators will rely on this network for control and proper operation. And in addition to providing optimized building performance, some of this information may also be valuable for tenants in providing services, such as way finding, advertising, and ordering products.

Something as simple as light fixtures will become IP-based devices with energy-efficient LEDs and intelligent sensors to detect occupancy levels and lighting levels – and even interface with heating, ventilation and air conditioning (HVAC) controls. The LED driver will be “addressable,” meaning that it will carry a unique IP address on the building network. This gives it the ability to either be controlled by the building, or supply information back to the building network. In some cases, the method of feeding power to these devices will change as POE (Power over Ethernet) equipment is developed. A POE light fixture receives its power from the network, potentially saving the wiring and distribution costs associated with traditional wiring approaches. The interconnectivity of these devices and systems will be incredible, impacting everything from boardroom audio-visual (AV) systems and video conferencing capabilities to food courts and workspace designs.

Link to previous nSite issue: Building Intelligence: it's only smart

Let’s turn to commercial office condos. What challenges do they present?

Dan: S+A has worked with developers in designing flexible office condos which can be combined into larger suites to meet the owner’s needs. That means all the mechanical and electrical systems not only need to be adaptable to suit these various layouts, but must also allow each suite to be metered individually so that true costs can be charged to the separate owners. Not surprisingly, accurate and reliable metering systems are a critical consideration for this type of building.

With so much existing product on the market, where do you see the greatest opportunities for the retrofit part of S+A’s business?

Dan: We’ve been involved in some significant renovation and retrofit projects that range from historic structures to buildings that, from the outside, look modern but have systems that cannot compete with newer product. Fortunately, many of these buildings have “good bones.” That allows us to come up with plans that increase outside air to meet tenant densification, incorporate more airside heat recovery, and add greater capacity to the cooling system by utilizing more efficient equipment. In the end, we are often able to match the results of what the newer products on the market would offer. Creativity becomes a necessity when working within existing structures – but if you aren’t creative, opportunities will be missed.

Link to previous nSite issue: Teaching old buildings new tricks