Captain Planet would likely approve of the Snoqualmie Valley School District’s updated light bulbs, not to mention its new geothermal system at Mount Si High School.
Using funds from a $27.5 million school bond, construction crews are changing all of the district’s inefficient light bulbs, as well as installing improved heating, ventilation and air conditioning systems at three of the district’s schools — Opstad Elementary, Chief Kanim Middle School and Mount Si High School. Because of its large size, Mount Si also will receive a geo-thermal system.
After all of these changes are implemented, the high school could cut its energy use by as much as 60 percent, said Clint Marsh, construction program manager for the Snoqualmie Valley School District.
“That’s a huge savings that goes on every year, after we’re done with that project,” Marsh said.
Mount Si’s old heating, ventilation and air conditioning system had outdated and broken boilers and chillers that failed to heat and cool the school properly.
Construction crews gutted the old system and will install a geothermal unit, using the power of the below aquifer to maintain the perfect temperature.
Crews will drill one heating line and one cooling line 550-feet below the earth’s surface, where they will come in contact with an underground waterbed known as an aquifer. The aquifer maintains a temperature of about 55 degrees Fahrenheit year-round.
During the winter, 55 degrees is warmer than the average outside temperature range of zero to 40 degrees. During the summer, 55 degrees is usually cooler than the average temperature range of 50 to 90 degrees.
The mostly-constant temperature of 55 degrees should serve Mount Si well. The geothermal system will have two separate piping systems: one flowing through the school like veins and the other circulating through the aquifer.
If the school is too cold, sensors will alert the system and catalyze a heat exchange. The school’s pipe water will flow to a heat exchange unit, where it will meet, but not mingle, with warmer water from the aquifer.
After it is warmed, the pipe water will return to the school at a higher temperature to heat classrooms and common spaces. The aquifer water will return to the aquifer at a lower temperature.
The opposite will occur when temperatures are too high.
The amount and the temperature change of the returning water will be so small it will not affect the aquifer, Marsh said.
The old system worked in a more inefficient manner. Electricity-using boilers and chillers ran about 60 percent of the time, ensuring a respectable temperature in the school. The new system only requires electricity for its pumps and two emergency backup boilers.
The new system has 160 cooling and heating fan-coil units, and can target a specific area. This should save the district money, as one area can receive more heating without turning on the heat in other parts of the school.
Also, unlike the old system, the geothermal structure has more options than “on” and “off.” Instead of turning on the heat full blast, the geothermal system offers varying degrees of heat.
“The potential for energy-saving on this is huge,” Marsh said.
Marsh hopes the geothermal system will qualify for a federal grant. The $5.2 million project is already set to receive a $500,000 grant from Puget Sound Energy.
“These systems are expensive, but since the school is thinking long-term, they become a very good investment for the district and for the taxpayers,” Andy Wappler, PSE spokesman said.
The district may receive another $500,000 grant from PSE, this time for replacing all the district’s inefficient lighting fixtures with energy-efficient fluorescent bulbs.
The district is spending about $1.3 million to install efficient light bulbs and design an efficient electrical wiring system for it.
The new bulbs will use less energy, but produce the same amount of light.
According to Marsh, energy efficiency is in PSE’s best interest. It would cost the company a bundle to build more transmission lines or another energy source, like a power plant. If Mount Si is using less energy, PSE can divert that saved energy to other establishments.
“The energy we save is cheaper than energy produced,” said Tisha Helmer PSE, senior account manager for business account services.
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