HVAC Energy Efficiency
Management done simply and affordably
As published in Worship Facilities, Sep/Oct 2006
Most of us have been there … opening up the electricity bill at the church and going into a mild panic, thinking, "I can't believe the bill is so high again this month! We've got to do something about this, but what?" Take a deep breath, as there are several things you can do to help lower your bills and keep your church comfortable.
There are two major contributors to your electricity cost (besides the obvious rising cost of energy itself) which are manageable: the lighting and the HVAC systems. These two items will account for up to 70 percent of your overall monthly expense. There are several ways to save electricity, and you can find endless resources on the Internet about lighting control and daylight harvesting, so it's wise to concentrate on impacting HVAC energy expenses.
The HVAC equipment in your church will vary depending on the architectural style, age of the building(s), and expansions that have taken place over the years. You may have a mixture of everything including several residential-grade split systems, rooftop units and central plant systems. Central plant systems are typically installed in very large churches conditioning very large areas and require complicated building management systems for control. These systems usually have energy management built into the control system, and the majority of churches will contain popular split systems and rooftop systems.
Energy savings for all systems which use standard 24VAC thermostats (just like your home) fall into two basic categories: maintenance and thermostat control. Maintaining a church's HVAC gear is important to the operating efficiency. Make sure you follow the guidelines set up by the manufacturer of the equipment. Little things like clean filters can make a big difference. You will probably find it interesting to talk with neighboring churches that are about the same size and find out if your energy bills are in line with theirs. If your bills are substantially higher, it will be well worth the money to find a local HVAC energy consultant to do an audit of your facility. As an example, just this week I heard about a situation where a fresh air controller (very important to the indoor air quality of your church) was set up wrong by the installing contractor. It was delivering three times too much fresh air to the building and running 24 hours a day. Correcting the problem reduced the overall energy bill by nearly 15 percent.
All-Important Thermostats
Once the equipment maintenance issues are regularly scheduled and you know there are no gremlins in your systems, it's time to concentrate on the item that frustrates so many of us both inside and outside the business of daily HVAC control … thermostats. They make us comfortable, and they can cost us a lot of money. The basic issue is that we all have our own internal thermostats that are set differently and most of the time we have better things to think about than remembering to set back the thermostat when we leave the area. When you combine our human nature with the complex myriad of HVAC system types, air flow, building construction, the number of people in an area fluctuating greatly and part-time building use, it is easy to understand why thermostats sometimes have a tough time keeping us comfortable.
We've all seen and played with single set point thermostats. Whether they are mechanical or electronic, they are designed to be very inexpensive and easily adjustable, but seldom do they handle control of the temperature very well. It's not uncommon to see a substantial number of these types of thermostats in a church, often because there was no budget at the time of construction for anything more than simple on/off control. Of course, this can lead to a very expensive problem. Because they are usually in the area to be controlled, anybody can get to them, turn the cooling down to 60 degrees and then leave the area 20 minutes later — leaving the HVAC system cooling in a near frigid environment for hours or days without anyone around. Not only does this kind of activity cost money, it is also very hard on the equipment and can shorten its operational life.
While simple thermostats may make sense in a few areas, programmable and network-based thermostats are oftentimes much more suitable. Most ‘commercial grade' programmable thermostats have several features which improve efficiency and control. Programmable thermostats often are thought of as residential or commercial. Residential versions have 5-2 programming, meaning five days of the week (Monday through Friday) will have one set of schedules of typically four events a day — one each for morning, afternoon, evening and night. The ‘2' is the other set of schedules for the other two days (Sunday through Saturday). This works fairly well in a residential environment because the majority of homes can operate a similar schedule during the work week and another on weekends. Obviously, this can make programming tricky for a complex environment like a church because there can be so many individual activities throughout the week, all at different times.
‘Commercial' programmable thermostats help overcome these constraints with seven-day programming; meaning each day of the week can have up to four different scheduled events. As an example, this makes it much easier to have a weekly Tuesday evening activity and not have to heat or cool the same area of the building on Monday, Wednesday, Thursday and Friday. Commercial versions also allow ‘program override' buttons for temporary temperature adjustment for unscheduled events. A very important concern is the ‘hold' button found on many programmable thermostats. In many cases, the ‘hold' button gets misused as a permanent adjustment and when that happens, all of your energy savings get thrown out the window. Some commercial thermostats solve this problem with password protection built right into the thermostat.
The best of all thermostat controls are network thermostats. Network thermostats are designed to replace the standard or programmable thermostat (new or retrofit) and add communications capability and substantial control without being complicated. When there are more than four or five programmable thermostats in a church, it can become difficult to manage. With network thermostats such as the XCI network thermostat systems, programming and controlling all of the thermostats in a church is as simple as point-and-click from a PC, which can be in the church office or literally anywhere in the world. In addition, the size of the network is unlimited whether there are one or 10 buildings and two or 200 (or more) thermostats. Schools and churches are adopting network thermostat systems not only because of their simplicity and power, but also because they are affordable and allow for the system to expand as budget, time and the size of the facilities grow.
One of the favorite features of these systems is the reliability of setting schedules and knowing that those schedules can't be adjusted by an unauthorized person by pushing buttons on the thermostat, while having the flexibility of allowing an individual to adjust the set point by only a few degrees for a few hours. The system is smart enough to return the thermostat to the scheduled temperature after that time, thus giving comfort, flexibility and control. Other flexible features of these systems allow remote temperature sensors, universal settings for all thermostats, efficient control algorithms, Ethernet and Internet access capabilities, trending, graphing and even open software interfaces to other management control systems.
Interfaces Improve Customization
One such powerful interface for the XCI Network Thermostat system is the ‘ThermoNightHawk' interface by AEFMG to the popular Dean Evans Associates software platform called EMS (Event Management Systems). This event scheduler is widely used in churches to manage which rooms and buildings are reserved for weekly or one-time events from worship services to bible studies to weddings. The interface uses room occupancy information from EMS to control thermostats throughout a facility, automatically bringing a room to the desired temperature prior to a scheduled meeting or event and then shifting to a more energy-efficient temperature setting when the room has been vacated. Energy consumption figures at a Texas site show savings of up to 22% ($2,000- 3,000 per month) in a 70,000 square foot facility. While 22-percent savings may seem substantial, they are very realistic in many situations simply because better control is available. The percentage and amount of money saved will vary in every situation based on usage and the climate.
With any of the different thermostat solutions presented, the goal is "be comfortable" when the area is occupied, manage user adjustments and to be able to reliably set back the temperature when unoccupied to save money. The key to success is to examine your facilities, determine which type of thermostats (manual, programmable or networked) work for each area, and implement your plan as time and budget allows. In many cases, installations can be done directly with church staff and volunteers.
Q U I C K - L I N K S
Dean Evans & Associates inc.
Integrated software solutions for event management and facility scheduling
(800) 440-3994
www.dea.com
XCI Corp.
Interfaces for network controllers;
XCI Network Thermostat
(972) 580-8001
www.xcicorp.com
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