Oppportunities for energy efficiency.

Given congregational facilities’ limited hours of operation and usually small or nonexistent budgets for capital projects, the best opportunities for improving their energy efficiency are usually low- or no-cost measures that reduce energy consumption while the building is unoccupied. Some of these measures simply involve changing the way con- gregants and staff use the building. Other measures require a modest investment but have quick payback and are often easy to justify. Bigger-ticket measures, such as replacing functioning air-conditioning equipment with more-efficient units, may simply not be practical until the existing equipment reaches the end of its useful life. A comprehensive energy audit is the best way to identify cost-effective opportunities in any congregational building.

Low- and No-Cost Conservation Measures

The following measures can be implemented very quickly at very little, if any, cost to the congregation.

Turn off the lights.
Simply turn off lights when they are not in use. Occupancy sensors can be cost-effective, but a less-expensive alternative would be to post reminders to ensure that switches are off when the lights are not needed and to train custodial staff to also switch off lights. Timers may be useful in daylit lobbies, entries, and vestibules to ensure that lights are off during daylight hours. Replace incandescent bulbs with compact fluorescent lamps (CFLs). CFLs can save between two-thirds and three-quarters of the energy consumed by the incandescent bulbs they replace. Energy savings usually repay the cost of the CFL within one year.

Control plug loads.
Plug loads such as microwaves, computers, and televisions may continue to draw power even when the appliance is turned off. For maximum energy savings, suggest that congregants simply unplug these appliances when they’ve finished using them or before they leave the building. Computers may be used daily in staff offices and should employ sleep-mode settings when the machines are not in use. The typical desktop computer, monitor, and shared printer draw about 200 watts (W), with the monitor alone drawing about 100 W. Computers should be turned off at the end of the workday. ”Smart” power strips that automatically turn off plug loads when they’re not in use are another low-cost measure. A smart power strip has an occupancy sensor or a programmable timer that turns equipment on and off. Another type of smart power strip, designed for computers, has a master outlet for the computer: When the computer is turned off, all other equipment plugged into the power strip is also turned off.

Delamp vending machines.
Suggest that congregants disconnect the ballasts for advertising lights in vending machines. The lights not only cost money to run but add heat to the refrigerated compartment. Turning off a vending-machine light can save about $100 a year.

Set back HVAC temperature.
Due to congregations’ relatively short hours of operation, programmable thermostats can be particularly cost-effective. These thermostats will usually yield more-reliable energy savings than manual temperature setback. To help ensure continued savings, post clear operating instructions for members, volunteers, and staff so that the normal thermostat schedule is not erased when space conditioning is needed for an unscheduled event.

Heat and cool during occupied hours only.
Certain parts of a congregational facility—for example, the worship space—are used only during specific times of the day or week. Make sure that HVAC settings are at minimum levels or off during non–use periods. See also “Demand-Controlled Ventilation” in the “Higher-Cost Measures” section below.

Turn down water heaters.
Where pos- sible, turn down water heaters on low-occupancy days. Bathrooms and kitchens used primarily during worship services are particularly good targets for lowering water temperatures.

Low-Cost Maintenance Measures

The following low-cost maintenance practices can keep existing equipment operating at peak efficiency.

Check air-conditioning temperatures.
Check the temperature of the air coming out of the register nearest the air-conditioning unit and compare it to the temperature of the return air going to the air conditioner. If the temperature difference is lower than 14° Fahrenheit (F) or higher than 22°F, have a licensed technician inspect the air-conditioning unit. Check for restricted airflow. If suction makes it difficult to remove the cover of a fan cabinet, the return airflow to the HVAC unit may be restricted. Return grilles may be covered, or dampers may be closed by mistake.

Change filters.
Filters should be changed on a monthly basis—more often if the congregation is located next to a highway or construction site where more dirt is in the air.

Clean condenser coils.
Condenser coils should be washed thoroughly at the beginning and end of the cooling season. Check cabinet panels. Ensure that the panels to rooftop air-conditioning units are fully attached with all screws in place, and verify that gaskets are intact so no air leaks out of the cabinet. Chilled air leaking out can cost $100 per rooftop unit per year in wasted energy. This check should be performed on a quarterly basis. Direct airflow. Shut off the registers in any unused rooms in order to direct forced air to where it is needed. If some rooms overheat while others are too cool, call in a qualified heating contractor to balance the distribution of heated air. Another way to balance warm airflow is to cover the metal discharge grilles in rooms that overheat.

Close vents.
In place of air conditioning, many older buildings have natural ventilation systems to remove hot air in the summer. Be sure to close these vents in the winter, or they will exhaust heated air. Maintain existing economizers. Many air-conditioning systems use a dampered vent called an economizer to draw in cool outside air, when it is available, to reduce the need for mechanically cooled air. Have a licensed technician check, adjust, clean, and lubricate economizers each year. One stuck in the open position will draw in too much hot air during the air-conditioning season and too much cold air during the heating season. That problem can increase annual HVAC costs by 50 percent. If necessary, adjust the outdoor intake setting on your economizer.

Seal gaps.
Use caulk and weather stripping to seal gaps around windows, doors, chimneys, and other structural elements. If possible, use caulk or expanding foam to seal the gap between the top of the foundation and the wall that sits on top of it. Prevent waste in water use and water heating. Insulate hot water pipes by wrapping the first 3 to 6 feet of hot water supply with pipe insulation. Fix leaky faucets, showerheads, pipes, and toilets. Monitor and measure. Use a plug-in power monitor to meter electricity usage in appliances and office equipment before and after turning them down and off in order to demonstrate and encourage savings. Visit the congregation in the early-morning hours to note tempera- tures, lights, and sounds; then take measures to reduce unnecessary overnight energy usage. Monitor energy usage by reading meters morning and night or by using a data logger to record measurements of temperature, relative humidity, light intensity, and amperage.

Higher-Cost Measures

Congregations often present opportunities for energy savings that are highly cost-effective but require sometimes significant up-front investment. As a customer sector, congregations tend to have little money for capital investment and tend to be averse to diverting funds that would otherwise be used to support charitable or spiritual activities. But if you can demonstrate that an investment in their facility’s efficiency will provide additional funds for such purposes in the future, congregational leaders may decide to move forward even with very costly measures, particularly when they can capitalize on a project as a demonstration of good environmental stewardship.

Not all of the following measures will be cost-effective in all congregational facilities. A comprehensive energy audit can identify the most cost-effective improvements to congregational buildings and the energy-consuming equipment they contain. The Interfaith Coalition on Energy, an organization dedicated to working with congregations to reduce the costs of operating their facilities, provides energy audits to congregations. Other organizations familiar with the unique characteristics and energy requirements of congregational buildings are the Regeneration Project of California and its affiliate state-based Interfaith Power & Light organizations. Contact information for these organizations is provided in the “Other Resources” section.

Recommissioning.
Recommissioning is a process in which engineers check and tune up existing building systems to ensure that they are operating appropriately and efficiently. If possible, recommend engineers with expertise in recommissioning congregational buildings. Studies have shown that continuously monitoring a building’s energy systems can lead to reductions of 10 to 15 percent in annual energy bills. Savings typically come from resetting existing controls to reduce HVAC waste while maintaining or even increasing comfort levels for occupants. Recommissioning usually costs between 5 and 40 cents/ft2. Buildings should be recommissioned periodically to ensure that efficient operation is maintained.

Fluorescent lamps.
Given the EIA survey data indicating that only about 17 percent of congregational buildings constructed prior to 1980 have conducted a lighting upgrade since that year, there appears to be a significant opportunity to improve lighting efficiency and quality by replacing T12 fluorescent lamps with modern T8 lamps and electronic ballasts. Adding specular reflectors, new lenses, and occupancy sensors or timers can double the savings. Paybacks of one to three years are common.

Light-emitting diodes (LEDs).
LEDs can be an efficient choice for both exit signs and holiday lighting. LED exit signs can last 15 years and typically use less than 20 kWh per year, compared to conventional exit signs that consume over 200 kWh per year and require bulb replacement at least every 8 months. The payback for replacing an existing incandescent sign will often be less than 3 years—even less when maintenance cost savings are included. LED holi- day lights are also now available in a variety of colors and designs from retailers. LED holiday lights use far less energy, last many times longer than other light sources, and are more durable. However, LEDs are still not an efficient or cost-effective choice for general space lighting.

Daylighting.
Encourage congregations to take advantage of daylighting where possible to reduce the need for electric light. Proper design is critical to avoid glare and overheating. Light shelves, installed high inside or outside a window, will shade and prevent glare in the bottom six feet of a floor, which is where most staff work. The shelves also reflect daylight up onto the ceiling, which indirectly illuminates a room.

Occupancy sensors.
Install occupancy sensors in bathrooms, utility closets, and other less-used spaces to control lighting in response to movement. Occupancy sensors may also be suitable for spaces such as staff offices. Select sensors that turn lights off when no one is present rather than ones that turn lights on when they sense occupancy. The latter will sometimes turn lights on unnecessarily.

Parking-lot lighting design.
Most parking lots are designed with far more lighting than is recommended by the Illuminating Engineering Society of North America. An overlit lot can be dangerous to drivers if their eyes cannot adjust quickly enough in the transition from highly lit to dark areas. When designing lighting for a new parking lot, consider using lower-wattage metal halide lamps instead of higher-wattage high-pressure sodium lamps in fixtures that direct the light downward. Even with a lower wattage, a congregation could safely use fewer lamps if this choice is made. Metal halide lamps emit more light in the blue part of the spectrum than do sodium lamps, which makes them a more effective lighting choice even though they are less efficient on a lumens-per-watt basis. In recent years the larger CFLs and induction lighting have become viable options for outdoor lighting. They offer good color quality and better controllability than metal halide lamps. Induction lamps offer very long lamp life, which leads to reduced maintenance costs. Also, if they’re not already being used, recommend timers for all outdoor lighting.

High-efficiency HVAC units.
A highly efficient packaged air-conditioning and heating unit can reduce cooling energy consumption by 10 percent or more over a standard-efficiency commercial packaged unit. In some facilities it may be cost-effective to replace HVAC equipment immediately. In others, replacement won’t make sense until the existing equipment fails. A qualified energy auditor, preferably one who is familiar with congregational buildings, can determine potential energy savings for a given facility. Given the variable occupancy and loads common to congregational buildings, it makes sense to recommend equipment that has multiple levels of capacity (compressor stages) and good part-load efficiency.

Evaporative cooling. This type of system uses the natural cooling of evaporation and is especially effective in warm, dry climates. It typically uses less than 25 percent of the energy of a vapor-compression air-conditioning system. First costs may be higher than for a vapor-compression system, but paybacks can be rapid: six months to five years, depending on climate.

Demand-controlled ventilation (DCV).
For spaces that have large swings in occupancy, congregations can save energy by decreasing the amount of outdoor ventilation air supplied by the HVAC system during low-occupancy hours. A DCV system senses the level of carbon dioxide (CO2) in the return air stream; using that level as an indicator of occupancy, the system decreases the amount of outdoor air supplied to the space when CO2levels are low. DCV systems are particularly applicable to variable-occupancy spaces such as worship spaces, meeting rooms, and cafeterias.

Economizers.
Where existing HVAC systems do not have economizers (and DOE survey data indicate that most congregation facilities do not), suggest that an auditor investigate the cost-effectiveness of retrofitting an economizer onto existing HVAC equipment.

Windows.
Replacing windows is expensive. In cold climates, it may be cost-effective to replace old, single-pane windows with more-energy-efficient (low-emissivity) windows. For stained-glass windows, protective glazing such as laminated glass or polycarbonate will decrease drafts—but without proper ventilation and proper glazing, such treatments may cause damage to the stained glass. On plain-glass windows, use window treatments such as drapes and shades; on walls of south-facing windows, use awnings or window film to block solar heat gain in the summer and reduce the air-conditioning load.

Cool roofs.
These are not suitable for all congregations, but when it’s time to replace the roof, materials that are white or another highly reflective color will minimize the amount of heat the building absorbs. This change can often reduce peak cooling demand by 15 to 20 percent. Landscaping. Deciduous trees, planted on the west- and south-facing sides of buildings, will shade windows, reducing solar gain and therefore air-conditioning needs during the summer months.

 

Information from: "ESource", 2006. www.esource.com.

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