Landscaping
Although not frequently given much consideration when planning a Data Center project, landscaping—encompassing not only lawns and vegetation but also the artificial surfaces on a property—has a significant effect on how green your facility is, influencing building heat loads, water usage, air quality, and other conditions.
Be strategic about what you plant on your land and where. That means not only using drought tolerant and low maintenance plants, but also placing trees in key locations to shade buildings and areas that can otherwise absorb and store unwanted heat, such as parking lots.
If your Data Center project involves building new structures, or expanding existing ones, don't indiscriminately move earth and demolish trees and other vegetation. The goal is to minimize disruption to the land and, where possible, reintegrate natural components. For instance, if you need to remove trees during construction, try to replant them elsewhere on the site.
Figure 3.1 shows workers relocating a tree to make way for Data Center construction. The tree was moved to a makeshift tree farm on the building site, shown in Figure 3.2.
)
)
In Figure 3.3, a few feet (one meter) of dirt is excavated from the ground floor of a building to make room for a sunken Data Center raised floor. Figure 3.4 shows the amount of soil removed from the building in a period of 24 hours.
)
)
To reduce water usage, avoid pollution, and reduce your maintenance costs, you need to implement good landscape management practices, including the following:
- Irrigate efficiently: Don't overwater, which not only consumes more water, but can also cause vegetation to grow faster and, therefore, require additional maintenance.
- Use mulch: Place mulch in planting areas to insulate foliage, reduce water usage, and limit erosion. Where possible, reuse plant clippings or wood waste from your own property as mulch.
- Leave grass clippings on lawns: Grass clippings decompose over time. This is good for the lawn, providing nutrients from the clippings, avoiding the need to dispose of the green waste, and reducing water and fertilizer usage.
- Limit pesticide usage: Consider solutions for controlling unwanted weeds and insects that don't involve chemicals so as to maintain good air quality.
- Avoid excessive pruning: Pruning can trigger faster growth, requiring additional maintenance activity.
Be aware that many green elements that are effective for the exterior of your building can also be incorporated onto your overall property. For instance, the same advantages of implementing a cool roof—lowering energy consumption to cool a building and reducing heat islands—can be gained by implementing cool pavement, consisting of materials with high solar reflectance and thermal emittance.
Likewise, photovoltaic components can be installed on your property to harvest solar energy. Solar canopies for parking lots can perform double duty at a building site, both generating electricity and providing shade for employee vehicles. Street lamps are also available that can be powered by solar energy alone or by a combination of wind and solar energy.
Consider using pervious concrete or porous asphalt for paved locations on your property such as sidewalks, parking areas, and curb and gutter systems. Unlike conventional paving, pervious materials enable water to seep through. This reduces storm-water runoff, helps recharge groundwater, and better transfers cooler temperatures from the earth below to the pavement, reducing heat island effects. Rubberized asphalt, mentioned at the beginning of this chapter as a green material because it uses ground up scrap tires that would otherwise end up in landfills, is available in pervious form.
You can reduce water usage at your site by collecting and storing rainwater, using it for nondrinking activities such as watering vegetation and (after treating the water) flushing toilets. Rainwater harvesting equipment consists of a catchment (typically atop a building roof) to collect the water, a distribution system (angled roof features, gutters, downspouts), and a container to store it (a cistern).
How much water can you expect to collect? That depends upon the size of the catchment and how much rain falls in the region. To make an estimate, multiply the size of the collection area by the average amount of rainfall for a given period.
For instance, if your catchment area is 20 feet long by 50 feet wide and the area receives 24 inches of rain per year, that's 20 feet x 50 feet x (24 inches / 12) = 2000 cubic feet of water. Multiply by 7.48 to convert to gallons; 2000 cubic feet x 7.48 = 14,960 gallons.
Using metric figures, that's a 6.1 meters x 15.2 meters x (61 centimeters / 100) = 56.6 cubic meters of water. Multiply by 1,000 to convert to liters; 56.6 cubic meters x 1000 = 56,600 liters. (Note: The end calculations of 14,960 gallons and 56,600 liters don't convert exactly due to rounding of metric measurements.)
This is an idealized number because it does not account for water spillage or evaporation, both of which reduce the total water yield.