Summer can be a busy time for congregations with seasonal activities for children, maintenance and landscaping projects, and switching the building from heating to cooling mode. The spring to summer transition is also a key time to evaluate the efficiency of your heating and cooling system and to give the system and your facilities a maintenance “tune-up.”
Most faiths teach stewardship of financial and natural resources. Energy efficiency is an excellent means of achieving both objectives at the same time, because energy saved is money saved and pollution prevented. When you think about air-conditioning your house of worship, you want to provide the highest level of comfort at the lowest possible cost. Putting Energy into Stewardship is a free ENERGY STAR online guide that can help you get the most from your air-conditioning equipment and decrease your operating costs.
Heating, ventilating, and air conditioning (HVAC) systems typically account for 39% of the electric energy used in commercial buildings in the United States. Consequently, almost every congregation has the potential for significant savings by improving its control of HVAC operations and improving the efficiency of its system.
Before evaluating the efficiency of your heating and cooling system, the first step is to reduce your building load (i.e., how much heating and cooling you actually need). Reducing your facility’s load allows existing systems to operate less frequently; newer systems can be smaller and more efficient, thereby lowering operating costs. The most common form of load reduction is the “tightening” or “sealing” of your building.
Added up, small holes and leaks can quickly amount to the equivalent of leaving a door open 24 hours a day. The good news is that there are many low-cost/ do-it-yourself actions available. For example weather-stripping is a “sealing” technique typically done around movable structures such as windows and doors.
If your current weather stripping is hard or cracked from ageor missingit should be replaced. Caulking is another improvement for stable, non-moving areas such as cracks in the wall, around electrical openings, and where the floor meets the wall.
In addition, caulking and weather-stripping are valuable community services your youth group or other volunteers can take into the community, especially for elderly or low-income citizens’ homes. Another important way to reduce your facility’s cooling load is to upgrade your lighting systems before any major HVAC project. Energy efficient lighting, such as T8s (fluorescent lamps), compact fluorescent light bulbs (CFLs), and light-emitting diodes (LEDs) provide high quality light, but operate much “cooler” than older inefficient systems. Energy efficient lighting also helps lower your air-conditioning requirements.
Other load-reducing techniques, such as proper insulation levels (roofs, walls, and foundation), radiant barriers, and energy efficient windows, are more costly but play a critical role in air and moisture infiltration control. If these systems are in poor condition they can contribute to heating and cooling loads and indoor air-quality concerns. When a new facility is being constructed it is also important to insulate the building to meet the latest model building energy codes. For new windows, consider ENERGY STAR-qualified options that feature a combination of money-saving technologies such as inert gas fills (e.g., argon), low-emissivity coatings, and insulated frames. For existing facilities, efficiency upgrades are typically most cost effective during renovations or when the building structure is bare and accessible.
Never oversize your heating and cooling equipment, especially after reducing your internal loads. If your congregation is installing a boiler, furnace, heat pump, room air conditioners, roof top unit, or chiller, for example, avoid oversizing the unit for the square footage. Oversizing equipment increases the capital cost at the time of the installation and the operating costs over the life of the unit. Another tip at purchase is to have your HVAC professional provide you quotes and specifications (including lifecycle costs) comparing standard-efficiency and high-efficiency units. If the lifecycle cost is less on the high-efficiency unit, purchase it.
Furthermore, a “too-big” unit does not deliver discomfort. An oversized air-conditioning unit cools the building more quickly than it removes humidity, and humidity can be as important to comfort as temperature. Engineers call this remaining humidity after a too-quick cool down “latent heat.” You will recognize it as a damp, clammy feeling from improper cooling.
Energy recovery ventilation systems reclaim waste heat from the exhaust air stream and use it to condition the incoming fresh air. In humid climates, consult your HVAC professional about supplemental dehumidification. Reducing the humidity of a facility in a warmer climate increases occupant comfort and reduces costs by allowing thermostat set points to be raised a few degrees with no loss in comfort. In cooler climates, consider specifying economizers that draw in fresh air when the temperature outside is lower than the temperature inside.
Congregational facilities have unique needs because their energy-use patterns are often very different than other buildings. Typically, energy use tends to peak on weekends and lessen during the rest of the week with occasional spikes for special meetings and other functions. A congregation that designs or upgrades their facility with this in mind will be more likely to maximize energy savings.
A great way to reduce the energy used for heating and cooling is to incorporate control strategies that ensure systems are used only when necessary. Common more comfortin fact, it can cause control strategies include ENERGY STAR qualified programmable thermostats and/or network thermostats, multiple zones, and CO2 demand sensors. These strategies can be specified on new heating and cooling systems and retrofitted to older systems as well.
ENERGY STAR-qualified programmable thermostats are simple, easy to install thermostats that allow convenient night/ weekend temperature setbacks to save energy and money. Models range from $50 to $200 depending on the desired features and usually include manual overrides to ensure comfort at any time. Multiple Zones divide your facility into several heating and cooling zones, a strategy that allows your system to deliver more efficient heating and cooling by eliminating inaccuracies from a central sensor point. If your house of worship has many rooms or floors, multiple zones are recommended.
Just like your automobile engine, your facility’s heating and cooling systems need maintenance. Contract with a qualified local HVAC firm for regular maintenance “tune-ups” before cooling and heating seasons. During these maintenance calls, a technician should:
- Clean the evaporator and condenser coils on your heat pump, air-conditioner, or chiller. Dirty coils inhibit heat transfer.
- Check combustion efficiency, refrigerant charge, and belt tension as applicable.
- Inspect ducts and piping for leakage or damaged insulation. Leaky ductwork is one of the biggest contributors to cooling loss in buildings. Apply duct sealer, tape, and insulation as needed.
- Repair old valves and steam traps. These can waste hundreds of dollars and are inexpensive to replace.
In addition, your congregational staff or grounds committee can contribute to critical seasonal maintenance by replacing or cleaning HVAC air filters each month during peak seasons.
Along with HVAC maintenance, it’s just as important to measure your progress. ENERGY STAR provides free software tools and training for “benchmarking.”
Benchmarking is a crucial step in the overall ENERGY STAR strategy for superior energy management by allowing church staff to measure energy usage . To assist congregations in benchmarking, ENERGY STAR offers the Portfolio Manager tool, available for use free of charge with free online training. Visit www.energystar.gov/benchmark for more information.
In addition, the ENERGY STAR Congregations Network provides a range of technical information, support, and public recognition for success. Visit us at www.energystar.gov/congregations.