Commercial Energy Audit by Students at Shoreline Community College

Last week Shoreline Community College students gave a presentation of their findings of the audit they performed for the Parent Child Center building at Shoreline Community College. What they found and recommend are things that any owner of brick buildings built in about the same time period might face today.

The Parent Child Center building is a brick and concrete structure with double pane windows built in 1993. The 8,000 sq foot building was considered quality construction at the time of its design and construction. Approximately $10,182.00 is spent annually on electricity and $1,368.48 on gas. (There is only one electric meter for the entire campus so the electricity usage is scaled with occupancy times taken into account) 

The structure has excellent solar access for light and power. 

Heat Ventilation Air Conditioning (HVAC) system
Interior remodels including the addition of interior security doors and additional walls were found to be interfering with proper airflow. The result is that there are areas in the building that remain too cold and other areas that remain to warm. Supplementary heat and fans are used to offset these heating and cooling challenges. 

The building is heated with hot water from burning natural gas and is well maintained. However, the existing system is approaching 20 years old and is at the end of it life cycle. Overall heating plant efficiency is estimated to be no better than 50%. The remaining useful life of the building is estimated at 60 years.

The lack of cooling limits use of the facility on hot days. There is no air conditioning for the building. "State regulations that govern child care facilities have a specific maximum operating temperature of 82 degrees Fahrenheit." (WAC 170-295-5150) When temperatures exceed 82 degrees the children must be sent home.

During the report several options were presented for making adjustments to return the system to designed performance including Replace the existing system with a more efficient system of the same design. Other options were to add air conditioning or add air conditioning with thermal hot water system, which would reduce hot water and heating costs by supplementing part of the hot water needs with solar heated water.

Another option is to replace the existing system with a ductless mini split air conditioning and heating system and repurposing the existing duct system to a heat exchanging fresh air ventilation system. The benefits would be "Highest operational efficiency, decreased use of non renewable energy sources. " 

The students do not recommend this last option because it is the most expensive upfront but more important it would "require an extended suspension of operations." Shutting down the Parent Child Center is not an option as it is open all year round.

The students recommended replacing the existing system with a more efficient system of the same design and incorporating air conditioning as the most cost effective least disruptive method of meeting the needs of students and staff for heating and cooling comfort. 

This option would:

• Increase the efficiency of the heating system by 25%
• Replacing the system would reduce ongoing maintenance costs
• Air conditioning offers more comfort to staff and students and eliminates the need to close the building due to high ambient temperatures
• This option would require the least amount of disruption of facility operation
• Much of the existing HVAC air handling system is retained minimizing cost

Water Usage
Conservation through replacement of appliances and equipment with Energy Star Rated appliances was recommended. For example the clothes washer gets quite a bit of use. "New ENERGY STAR qualified clothes washers use advanced technology to dramatically reduce water use. Full-sized washers that have earned the ENERGY STAR use 10–20 gallons of water per load, compared to the 30–35 gallons used by a standard machine." Per the Energy Star website.

Replacing the top-loading machine with a front-loading machine will significantly reduce hot water usage and the amount of gas needed to heat the water. 

Students also recommended that all faucets and lavatories have flow restrictors added or upgraded.

Electric Usage
Most lighting is with fluorescent and compact fluorescent lights. It was suggested that the play area be converted from 205-watt lamps to LED's.

"Separate the lights near the windows from the interior in large rooms, and add occupancy and ambient light level sensors to the covered play area and most rooms."

"Add simple skylights to the covered play area and solar light tubes with dampers in the interior area of large rooms." 

In the kitchen it was found that the exhaust fan must run twenty-four hours a day because the pilot lights for the stove are on at all times. It was suggested to replace the stove range with a system where the pilots are off when the stove is not in use and are ignited with an electrical spark only when turned on. The "HVAC system needs to account for the varying loads of the exhaust fan." 

Solar Electric, Solar Hot water were also presented. If the building were first retrofitted per student recommendations then it would make sense to re-examine what size of a Solar Electric and Solar hot water would be required to meet the energy needs of the building. 

A student team reported that if a rooftop garden were installed it would reduce the heat gain in the summer and heat loss in winter reducing the load on the HVAC system. The roof top garden could also be part of a grey water collection system used to flush the toilets.  

My own take away from the report was to conclude that it would be a worthwhile investment to have the Heating system replaced with a more efficient system. A rooftop garden could potentially make an air conditioning component unnecessary or at least leave air conditioning only necessary a few days out of the year.