Solar panels and rainwater harvesting systems are two of the most well know sustainable design practices. While these systems can greatly reduce energy costs and demand on public electric and water utilities, there are also many other approaches that can be integrated into a project to save energy and reduce environmental impacts.
Marvin and I have had the pleasure of working with Richard Sniff, Owner at Power Forward, for the last several years. His firm provides mechanical, electrical and plumbing engineering with a special emphasis on renewable energy. His passion for sustainability is highlighted in his work designing the solar system interconnection for the Google Tower in downtown Austin, which has opened the door for other renewable energy design opportunities. We appreciate his creative and practical approach to introducing sustainable design ideas into projects on many levels – it makes him such an invaluable partner on our projects!
Below is a list that represents the variety of ways a design team can reduce energy and operational costs through system designs for either new construction or adaptive reuse projects:
Mechanical Systems
Variable capacity air conditioning systems. These come in a few different system types, but the most common are variable refrigerant flow (VRF) and variable air volume (VAV). All of these systems achieve higher efficiency and better humidity control by throttling down their capacity to match the immediate cooling load in the space.
Demand control ventilation. All buildings are required by code to bring fresh outside air into the building. For most of the year, this requires your HVAC system to use energy to bring that outside airstream to the desired setpoint. However, some system types are capable of providing outside air “on demand” instead of providing a constant flowrate. With demand control ventilation technology, HVAC controls adjust the amount of outside air supplied to the space based on measurements of carbon-dioxide given off by its occupants, thus saving previous resources.
Energy recovery ventilation. This system pre-tempers fresh outside air for the building by drawing out room temperature air and transferring heat energy between the two airstreams. Energy recovery ventilators may be used in combination with a dedicated outside air system or a traditional air conditioning system.
Condensate collection. This system can easily direct condensation from the HVAC system to a single holding tank which can then be used for landscape irrigation.
Plumbing
Rainwater collection. Designers can reduce dependence on the water utility or use this as an alternative way of bringing water service to a building in remote areas where an existing utility main may not be present. Rainwater harvesting systems should always be designed by a licensed contractor or engineer who specializes in them.
These are a few uses of rainwater collection systems:
- Irrigation – least treatment required.
- Grey water use, such as flushing toilets – moderate treatment required. - Potable water use for drinking, sinks and showers – most treatment required.
Hot water recirculation. This reduces water use by keeping hot water available in piping close to the point of use so that water doesn’t have to be drained before it reaches the desired temperature.
Low flow plumbing fixtures. These fixtures also reduce water usage by operating more efficiently and controlling the flow of water.
Water metering. Metering is not always required for projects like tenant fit-outs where a large group of customers are metered as a group, but collecting your own usage data can give you feedback to help gauge whether you want to take further conservation measures.
Electrical
Solar panels. Photovoltaic systems are a great way to reduce your carbon footprint; with the right financing and rebates they can actually generate revenue as a cash-positive investment. PV systems are best for owner-occupied projects with minimal shade.
Battery storage. Some battery storage systems can help ease strain on the power grid by discharging electrical energy during peak demand hours and charging during times when demand is low. Since some electric utility customers are charged based on their peak demand, this results in some customers’ electric utility bills to be reduced. However, battery systems can be expensive for this use and might not pay for themselves within their usable lifespan. Owners should consider carefully before taking this approach. Battery storage is best used for backup power to keep critical equipment running during an outage. The storage can be used to operate lighting, appliances, and computer equipment. However, owners should carefully consider using a generator if they anticipate that they will need backup power for HVAC systems or large motor loads like fire pumps or elevators.
Lighting controls. - Occupancy setback for parking. - Automated shades are a simple way to help reduce the amount of energy used by your HVAC system.
Electrical metering. This type of metering is always required by the serving utility, but in some case additional submetering on a building electrical system can provide feedback on how much energy is being used by specific pieces of equipment (like HVAC) so occupants can make informed decisions about conservation measures.
EV charging. Electric vehicles can have a great impact on reducing carbon emissions, but the
downside is that they cannot be quickly topped off at the gas station. Electric vehicle drivers benefit by often charging their vehicles while parked at their destinations, primarily at home and at work.
There is going to be a growing need for more
EV stations in multi-family garages, offices,
and other places where people spend large
segments of time, but they also require larger
electrical services. It can be costly to go upgrade electrical services from the utility for additional chargers, so it’s important to think hard about the full life cycle of a building and to make sure that you feel comfortable about the amount of EV charging infrastructure that you’re providing.
If you’re interested in using any of the sustainable mechanical, electrical or plumbing design practices listed here or if you have another idea, we’re happy to start the conversation with you. Reach out to us or Richard directly at richard@powerforwardeng.com.
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