Creating an energy efficient building involves many factors, but an efficient HVAC system is the key. In my last post, I talked about the money that businesses can save by instituting the latest advances in heating, ventilation and air conditioning (HVAC) systems.

Here are six such systems/technologies, each of which happens to come with its own acronym!

Variable refrigerant flow (VRF)

These systems use refrigerant fluid rather than of air or water. They are by nature ductless. They can be configured to provide different amounts of refrigerant at different times of day and year, and to different parts of the building (zones). This kind of system is best suited for small areas (1,000SF +/-) with limited space for ducts such as in small offices, shops, dwelling units, computer rooms, hotel/motel rooms, schools, banks etc.

Chilled beam cooling (PCB or ACB)

A passive chilled beam (PCB) is a series of tubes containing chilled water. Warm air in a room rises towards the beam on natural convection currents. The air is then cooled before it descends back towards the floor (and occupants of the room). This is quite energy efficient as no fan is required. A variation that uses more power but provides more cool air is called an active chilled beam (ACB). It pulls the air from the space into a cooling chamber and then forces it back into the room. This is still more efficient than moving air across an entire building.

Adjustable speed/Variable Frequency drives (ASDs/VFDs)

These drives save energy as they are able to lower motor speed and torque as load demand decreases. Some motors even have built-in VFDs in the form of microprocessors. These are also called “electronically commutated motors.”

Geothermal heat pumps (GHPs)

These pumps operate a heat exchange with the natural temperature of the ground or water a few feet below the surface depending on site conditions. This is more efficient than exchanging heat with the more volatile temperature of outside air. Ground temperatures in North America are warmer than air in the winter, and cooler in the summer. Moving heat rather than creating it is also more efficient. As a bonus, these pumps are quieter than their counterparts that use air.

Energy Recovery Ventilation (ERV)

These systems work by “double dipping” into the energy that is already being used to exhaust air from a building, transferring heat and moisture from incoming air into the outgoing air. ERV systems are best for buildings located in warmer, more humid climates.

Demand Controlled Ventilation (DCV)

While safety in the form of air quality is of course vital, some systems end up wasting energy by over-ventilating. More modern systems include sensors for carbon dioxide levels, which feed that information to the motors to help determine current environmental ventilation needs.

Electronic expansion valves (EXV)

Here once again is a system that work in the benefit of energy savings. Electronic expansion valves (EXV) is a device that allows for the control of refrigerant flowing through your HVAC equipment, typically the evaporator. As an electronic device, it provides faster, more accurate and steady response to demand of refrigerant flow in the system than the usual thermal expansion valve. This results in the right amount of energy being delivered to the load, hence helping to prevent wasteful usage.

Maintenance

The good news is that these greener HVAC systems usually require less maintenance than older systems. Most of the new systems come with software that tracks equipment use, and will let you know when it’s time for maintenance to keep it at peak efficiency.

Finally, two low-tech maintenance actions that can pay off: Sealing ducts and making sure your building is well insulated are crucial to avoiding the loss of the hot or cold air you’ve worked so hard to bring into the space.

Using energy-efficient heating, ventilation and air conditioning (HVAC) systems isn’t just good for the environment, it’s good for your bottom line.

Several studies have shown that HVAC systems use about half of the total energy use of commercial buildings, and therefore half of energy costs and a big portion of operation costs. Commercial buildings like office buildings, retail spaces and schools consume almost 20 percent of the United State’s total energy. Of these, office buildings consume the most.

The bad news is that from 1979 to 2012, commercial buildings almost doubled their electricity consumption, from 2.2 trillion BTU to 4.2 trillion BTU. The good news is that the efficiency of use in those buildings is improving. A 2012 government report showed an average total annual energy used per square foot of commercial buildings was about 80,000 BTU per square foot. This is down from 91,000 BTU per square foot in 2003, a 12 percent drop in just 10 years. It is expected that those numbers will keep dropping as heating, ventilation and air conditioning equipment improves in efficiency.

Meanwhile, according to 2016 U.S. Energy Information Administration estimates, New York businesses spend $42.35 Dollars a year per Million Btu for retail electricity. That works out to about $3.39 per square foot at the average usage rate reported in 2012. On average, New York companies provide about 125 to 250 square feet of space per office worker. A company of 200 people using 30,000 square feet of space could therefore easily be spending $100,000 in electricity costs.

Indeed, New York commercial businesses spent approximately $11 billion on energy costs in 2016, providing electricity to 545 million square feet of more office space than any other city on the planet.

If energy efficiency were improved by 10 percent, that would save New York businesses $1.1 billion!

The SmartMarket 2016 World Green Building Trends report shows that “green buildings” cost 14 percent less to operate than traditional buildings. For our hypothetical business using 30,000 square feet, a 14 percent improvement would be $14,000 in savings that could be used to invest in other areas.

Therefore it’s not a surprise that demand for green Mechanical and Electrical Engineering solutions is rising rapidly. A recent report predicts that global spending on energy efficient commercial HVAC systems will double in the next nine years, from about $30 billion to $60 billion.

In a future post, I’ll talk about some of those major solutions and systems, and which ones are right for different types of business spaces.

One of DOSE Engineering’s data center projects

When thinking about what your data center needs to do, you may be focused on the software security side of things: protecting business and client data, and making sure there are no disruptions to availability.

However, when designing a data center environment, there are many other factors to take into consideration. Your mechanical and electrical engineering (MEP) team must work together with your architect and construction manager if you are building from scratch, or your site selection team if you are looking at pre-existing space. Most importantly, your MEP team must work with your IT team.

Mechanical and Electrical Engineers can help with site selection, by evaluating several factors including square footage, usability of space, existing site mechanical and electrical system limitations and other constraints, as well as fire risk and scaling opportunities. They can help with planning how best to use the space, including the selection and layout of equipment for overheating and fire protection while maximizing usable floor area for data racks.

Your MEP team can evaluate the limits of the power available in a pre-existing space, and discuss potential upgrades to the infrastructure to provide additional power. They can also advise you on the most up-to-date systems to cool your data center, as well as control humidity.

Your MEP team can help you strategize around airflow and air containment. They’ll design a plan to help maximize the use of cold air coming into the center, and efficient placement of fans to exhaust hot air from individual pieces of equipment and the space, keeping a consistent room temperature for your equipment to operate at as near-ideal conditions as possible (hot aisle/cold aisle strategy). They can advise and install modern computer room air conditioner units (CRACs), and innovative green solutions for your data center.

Beyond equipment, they can advise as to installation of filler panels, the potential benefits of sealing equipment, and various options for cable management, all of which will reduce leaks.

Working with your IT personnel to understand what types of equipment are currently being used, and what replacement and scaling is anticipated in the future, the MEP team can give input on the design of racks, aisles and placement of equipment, including how to integrate free-standing equipment. The MEP team can also provide input on the best strategy for scaling by adding racks to a row or aisle. They can help design the center in a modular fashion, leaving room for growth and change.

A good MEP team can advise you on how to take advantage of the most efficient servers on the market, which use less power, especially when idle. They can offer options for battery backups and other power redundancy methods to ensure that even in a power failure situation, your data center will have access to electricity. They’ll be able to weigh in on the density of equipment around power supplies. They can also give input on how ceilings, floor space, columns, light fixtures can be worked around.

These efforts will result in reduced energy consumption and consistent operating costs. Only when you have consulted with an MEP team will you have a true grasp of the true costs and build-out schedule for your new or upgraded data center.