Schneider Electric in Rockford Illinois (formerly Barber Coleman) is closing. The manufacturing that is currently done in Rockford, IL will be moved to existing facilities in Clovis, California, Portland, Oregon and China. Schneider Electric’s Vice President of Press Relations, Marty Hanna told local news source WIFR that the company will move all production out of its Clifford Avenue location by the time the building's lease is up in March of 2014. Currently, 400 people currently work at the Loves Park facility. Of that 400, 240 positions will be eliminated. Schneider plans to keep 160 office employees in the Rockford area. They will look for a new location before the lease expires in March of 2014.
I'm here to learn. IF YOU KNOW OF A BETTER METHOD, LET ME KNOW!
Friday, September 28, 2012
Monday, September 17, 2012
Energy Conservation Measures - Thoughts on Lighting Control
I am not an expert on lighting by any measure. However, when I was recently asked about some ideas to conserve energy I couldn't resist looking at lighting control. Here is what I learned:
Daylight Harvesting - Daylight harvesting systems automatically lower light levels when adequate daylight is available. Sensors detect daylight levels and automatically adjust the output level of electric lighting to create a balance with the goal of reducing energy costs.
http://www.daytronicballast.com/images/2009_06_01_Sketch_Daylight_Harvesting_550.jpg
Occupancy Sensors – Occupancy Sensors to control lighting are an obvious way to reduce the amount of time when lights are on when they are not needed. I only mention it here because opportunities to use occupancy sensors are often overlooked. Like variable frequency drives, this is a mature technology that is underutilized.
LED Lighting – Another obvious but too often overlooked technology. Large scale replacement of incandescent lighting must be considered with the change in heat load in mind. Part of the reduction in electrical cost will be offset by an increase in heating load. Another point worth mentioning is that the color rendering index (CRI) that is possible with LED lighting has improved to a point where it may be possible to use LED lighting in settings where it was not possible in the past.
I'm here to learn. IF YOU KNOW OF A BETTER METHOD, LET ME KNOW!
http://www.daytronicballast.com/images/2009_06_01_Sketch_Daylight_Harvesting_550.jpg
Tuesday, August 7, 2012
Energy Conservation Measures - Working with the Sun
Working the with Sun
Here are some energy conservation measures related to the sun.
Use a transpired collector - A transpired collector reduces the load on a building’s heating system by heating intake air with solar energy. It preheats the ambient air by up to 40°F, reducing all or a portion of the load on a heating system during daylight hours. Although the transpired collector may not be able to achieve the required indoor air temperature on cloudy days or when the outside temperature plummets, it provides useful energy and reduces utility bills. In addition to meeting a portion of a building’s heating load with clean, free solar energy, the transpired collector helps save energy and money in other ways. It recaptures heat loss through a building’s south-facing wall; heat that escapes through the south wall is captured in the air space between the structural wall and the transpired collector and returned to the interior. Also, by introducing make-up air through ceiling-mounted ducts, the system eliminates the wasteful air stratification that often plagues high-ceiling buildings.
*Use solar assisted hot water heaters – I have seen these used with great success at Massachusetts Maritime Academy. The idea is to simply pump water through solar panels that pre-heat the water before it enters a boiler or water heater. These can be used with domestic hot water heaters as well as boilers. This works best with systems that require a significant amount of make-up water to be introduced to the system.
Solar Ventilation Preheating System for Combustion Air - Using solar ventilation preheating will decrease the amount of energy needed to heat combustion air.
Low Solar Heat Gain Glass - Use glass with a low solar heat gain coefficient (or SHGC) rating.
Cool Roof - Cool roofs are the roofs that can offer high thermal emittance and high solar reflectance. The ability to reflect the visible, infrared and ultraviolet wavelengths of the sun reduces heat transfer to the building.
If you know of a better method, Let me know!
Here are some energy conservation measures related to the sun.
Use a transpired collector - A transpired collector reduces the load on a building’s heating system by heating intake air with solar energy. It preheats the ambient air by up to 40°F, reducing all or a portion of the load on a heating system during daylight hours. Although the transpired collector may not be able to achieve the required indoor air temperature on cloudy days or when the outside temperature plummets, it provides useful energy and reduces utility bills. In addition to meeting a portion of a building’s heating load with clean, free solar energy, the transpired collector helps save energy and money in other ways. It recaptures heat loss through a building’s south-facing wall; heat that escapes through the south wall is captured in the air space between the structural wall and the transpired collector and returned to the interior. Also, by introducing make-up air through ceiling-mounted ducts, the system eliminates the wasteful air stratification that often plagues high-ceiling buildings.
*Use solar assisted hot water heaters – I have seen these used with great success at Massachusetts Maritime Academy. The idea is to simply pump water through solar panels that pre-heat the water before it enters a boiler or water heater. These can be used with domestic hot water heaters as well as boilers. This works best with systems that require a significant amount of make-up water to be introduced to the system.
Solar Ventilation Preheating System for Combustion Air - Using solar ventilation preheating will decrease the amount of energy needed to heat combustion air.
Low Solar Heat Gain Glass - Use glass with a low solar heat gain coefficient (or SHGC) rating.
Cool Roof - Cool roofs are the roofs that can offer high thermal emittance and high solar reflectance. The ability to reflect the visible, infrared and ultraviolet wavelengths of the sun reduces heat transfer to the building.
If you know of a better method, Let me know!
Friday, July 27, 2012
Energy Conservation Measures for Hospital HVAC
The goal of HVAC in a hospital is to provide adequate ventilation and occupant comfort as it relates to temperature and humidity. To save energy the goal should be to move and temper the air no more than necessary. My recommendations here will be focused on reducing the volume of air that is moved and figuring out ways to temper the air as little as possible.
Correctly size equipment – It is often the case that engineers will oversize equipment during new construction to ensure occupant comfort during initial occupancy. During a retro-commissioning effort, it may be possible to identify equipment that can be removed and replaced with smaller, more efficient equipment. If the return on investment does not warrant an immediate replacement, then the equipment should be identified for replacement with smaller equipment during routine maintenance or major repairs later in the building’s life cycle.
*Variable Frequency Drives - The most obvious place for savings is in the application of variable frequency drives. The cost of variable frequency drives has become so low that the application of a VFD to very small devices will often result in a very short time to recover the investment. In most cases where it is possible to slow down an electric motor, it should be done. Changes to a sequence of operation may be necessary, but are often worthwhile. The cube law is often used to show that a reduction in speed of 50% results in an 87% reduction in energy consumption (%Power = % Speed3 ).
*Eliminate 100% Outside Air Systems Wherever Practicable - Common areas that require 100% outside air are operating rooms (ORs) and labs. If 100% outside air AHUs are being used for differing space types that don’t require outside air, modulating outside air dampers and return air systems should be installed to reduce outside air. If a space is mixed use, it may be worthwhile to isolate it into separate spaces. Construction after initial occupancy can result in areas that are over-ventilated because first costs would have been higher to change the ventilation system to something more efficient.
*Demand Based Ventilation - The goal of demand based ventilation is to reduce the cost of ventilating a given space by reducing the number of air changes per hour (ACH) to the minimum level that will maintain the safety and comfort of the occupants. Typically the ventilation for an area in a building is designed to provide adequate ventilation in some hypothetical worst case scenario, or based on some assumptions about use and occupancy levels. Methods of demand based ventilation include controlling the level of CO2 or multi-parameter demand control where the levels of many contaminants are controlled.
*Reduce Outside Airflow Rates to ASHRAE 62.1-2010 - Most buildings are bringing in more outside air than they are required to per ASHRAE 62.1-2010. Outside airflow rates should be reduced to the minimum allowed by ASHRAE for each space. Consider installing CO2 sensors in return air ductwork and maintaining interior CO2 levels at <700 ppm above outside air CO2 levels during occupied hours. Also consider implementing an outside air damper reset schedule based on time of day and occupancy patterns within the building. During unoccupied hours and during morning warm-up cycles, all outside air dampers should be 100% closed. Even though much of a hospital is occupied 24 hours per day, there are probably opportunities to incorporate occupancy schedules in office space, auditoriums, and conference rooms. A careful review of the use of the space should be undertaken to make sure occupancy schedules are used wherever possible and are tightly controlled around actual usage times.
Multi-parameter demand-controlled ventilation system - This method of ventilation senses a variety of airborne contaminants and increases the ventilation rate to dilute and purge the affected spaces. The system utilizes multiple sample points or sensors that are placed in various areas of the hospital to measure contaminants in real time. Air samples are collected from each area every few minutes and analyzed locally or transported to a centralized sensor array for analysis. The goal is to eliminate over ventilation and the costs associated with running the ventilation equipment more than is necessary.
Fan Walls –A fan wall is a rectangular array of four to 300+ fans, all discharging into a single plenum. In a traditional system using large direct drive motors, it is common to see motor loads at 1/4th to 1/8th of their nameplate rating for a significant portion of their operating hours, resulting in reduced power factors and lower fan and motor efficiencies. To more closely match site conditions, a fan wall array can turn one or more fans off to allow the remaining fans and motors to be loaded at or near peak efficiency.
Recovery Devices – Energy recovery ventilation (ERV) recovers the energy contained in air that is exhausted from a space and using it to precondition the incoming outdoor ventilation air. During warmer seasons it pre-cools and dehumidifies while humidifying and pre-heating in the cooler seasons.
Pressure Independent Variable Air Volume - For non-critical spaces with lower ventilation requirements (such as medical office floors), consider switching to variable air volume systems and install variable frequency drives on all motors.
Displacement Ventilation - Consider using a displacement ventilation system rather than traditional overhead ventilation. Displacement ventilation is a room air distribution method where conditioned air is supplied at floor level and extracted above the occupied zone, usually at ceiling height. Such systems have the potential to improve both energy efficiency and infection control. In my opinion the jury is still out on energy efficiency, but infection control has made this attractive to hospitals. Your client may not realize enough of a benefit to apply this technology, but it is worth some consideration.
Displacement ventilation systems introduce cool air at low velocity, improving ventilation effectiveness within the occupant zone. As a room becomes warmer through use, the air and its contaminants rise, generally resulting in better air quality than exists in traditionally ventilated areas. Additional benefits of displacement ventilation follow. The idea is that energy is saved by reducing the number of air changes per hour and air is supplied at a warmer temperature.
Recent findings of the Healthcare Ventilation Research Collaborative (based on actual measurements) indicate that displacement ventilation with 4 ACH provides the same or better air quality for patient rooms than mixing ventilation at 6 ACH. http://www.reuters.com/article/2011/05/31/idUS221085+31-May-2011+BW20110531
Small Modular Boilers - Evaluate the opportunity to install multiple small boilers to meet the heating load of a given area. It is more efficient to operate smaller boilers when the heating load is 25% to 50% of the design capacity than it is to use one large boiler to meet a partial load. This is not always possible in hospitals if a large portion of the load on the heating system is from process hot water and steam use. If you find that the load on the heating system is not closely related to the outside air temperature, this may not be an option.
Wednesday, June 13, 2012
Saving Energy - ECMs for Hospitals
According to a 2003 U.S. Energy Information Administration survey of
commercial buildings, Hospitals are one of the largest consumers of electricity
in the commercial sector. They have the highest energy use per unit of floor
space, almost twice as much as the average office building. In a typical
hospital, lighting, heating, and hot water represent between 61 and 79 percent
of total energy use (depending on climate region).
This post will begin a list of ECMs (Energy Conservation Measures) related to HVAC and lighting in hospitals. Since my area of expertise is HVAC controls, I will be spending more time on this topic than lighting. This post will be followed by at least four more posts in the following areas; HVAC, working with the sun, lighting control, and building automation system changes.
There is a lot that can be done to save energy hospitals. With a good model of the building, a solid baseline, and good metering a detailed list of applicable proposals can be made. Most ECMs sound good taken in the abstract. You may find that many of these measures are not applicable or cost effective for a given project once they are screened against local climate conditions, building use considerations, local regulations, and incentives.
To achieve the highest levels of efficiency from any building, it will be very important to have a good record of the building's current consumption and the outside air temperature and humidity. Ideally, these will be obviously related. If they do not track each other well, this can indicate opportunities to "right size" or schedule equipment so that output can be more closely matched to demand.
In General
Process Changes and the regulatory environment - Incentives can play an important role in energy costs. For example, certain commercial rates in the USA are paid based on peak demand. You will get a lower rate per kWh, but you must pay as though you were at your peak consumption for the entire month. This would incent you to keep consumption steady and prevent any spikes. Changes in process and the timing of events could greatly impact your costs. For example, by monitoring consumption in real time the control system can be programmed to shed non-critical loads and alter set points to stay under a given threshold.
Trending and Continuous Commissioning - Before I dive into specific technologies which could be applied here, I would like to point out a problem that can occur in newer buildings. Buildings that employ newer technologies and employ creative applications of technology are the most susceptible to poorly executed maintenance. This may seem like a small matter and an uninteresting topic, but inattention to this problem is very costly. Maintenance personnel must understand the operation of the system and the reasoning behind the use of certain technologies. In many cases, there will be a trend toward simplifying systems and maintenance procedures at the expense of energy efficiency.
An occupied building with complex systems should employ frequent retro-commissioning. A lot of energy is wasted in buildings that are not performing to their potential simply because systems are not maintained properly, or have experienced an accumulation of minor failures. An automation system may mask problems like leaky valves and higher than necessary pressures which lead to waste. I believe most facility managers or owners would do well to employ someone to perform an ongoing analysis of systems information to ensure that everything is always performing optimally. I have had positive experiences with Cimetrics providing this sort of service with their Infometrics offering.
As an example, heating and cooling valves should be checked for proper operation. If a heating valve is closed and the supply air is still heated by the coil, the valve isn?t seating correctly and can cause simultaneous heating and cooling. This condition could be alarmed and reported so that corrective action can be taken.
Right Sizing and Matching Equipment to Current Applications ? Mechanical systems are often oversized or engineered for worst case scenarios. After a building is occupied and the actual use is known, there may be opportunities to correct the size and control sequences for equipment. Similar problems with size and control can also happen when areas of a building change function. If a system is too large, or delivers too much ventilation the tendency would be to leave it alone due to the impact on the first costs of a project.
An Example of incorrect sizing or incorrect sequences would be a lab space that had an extremely high number of air changes per hour (ACH) that has since been converted to office space. While the high number of ACH is not harmful to occupants, the cost to run the system is much higher than necessary.
In the near future I will post specific ECMs. In the meantime:
IF YOU KNOW OF A BETTER METHOD, LET ME KNOW!
This post will begin a list of ECMs (Energy Conservation Measures) related to HVAC and lighting in hospitals. Since my area of expertise is HVAC controls, I will be spending more time on this topic than lighting. This post will be followed by at least four more posts in the following areas; HVAC, working with the sun, lighting control, and building automation system changes.
There is a lot that can be done to save energy hospitals. With a good model of the building, a solid baseline, and good metering a detailed list of applicable proposals can be made. Most ECMs sound good taken in the abstract. You may find that many of these measures are not applicable or cost effective for a given project once they are screened against local climate conditions, building use considerations, local regulations, and incentives.
To achieve the highest levels of efficiency from any building, it will be very important to have a good record of the building's current consumption and the outside air temperature and humidity. Ideally, these will be obviously related. If they do not track each other well, this can indicate opportunities to "right size" or schedule equipment so that output can be more closely matched to demand.
In General
Process Changes and the regulatory environment - Incentives can play an important role in energy costs. For example, certain commercial rates in the USA are paid based on peak demand. You will get a lower rate per kWh, but you must pay as though you were at your peak consumption for the entire month. This would incent you to keep consumption steady and prevent any spikes. Changes in process and the timing of events could greatly impact your costs. For example, by monitoring consumption in real time the control system can be programmed to shed non-critical loads and alter set points to stay under a given threshold.
Trending and Continuous Commissioning - Before I dive into specific technologies which could be applied here, I would like to point out a problem that can occur in newer buildings. Buildings that employ newer technologies and employ creative applications of technology are the most susceptible to poorly executed maintenance. This may seem like a small matter and an uninteresting topic, but inattention to this problem is very costly. Maintenance personnel must understand the operation of the system and the reasoning behind the use of certain technologies. In many cases, there will be a trend toward simplifying systems and maintenance procedures at the expense of energy efficiency.
An occupied building with complex systems should employ frequent retro-commissioning. A lot of energy is wasted in buildings that are not performing to their potential simply because systems are not maintained properly, or have experienced an accumulation of minor failures. An automation system may mask problems like leaky valves and higher than necessary pressures which lead to waste. I believe most facility managers or owners would do well to employ someone to perform an ongoing analysis of systems information to ensure that everything is always performing optimally. I have had positive experiences with Cimetrics providing this sort of service with their Infometrics offering.
As an example, heating and cooling valves should be checked for proper operation. If a heating valve is closed and the supply air is still heated by the coil, the valve isn?t seating correctly and can cause simultaneous heating and cooling. This condition could be alarmed and reported so that corrective action can be taken.
Right Sizing and Matching Equipment to Current Applications ? Mechanical systems are often oversized or engineered for worst case scenarios. After a building is occupied and the actual use is known, there may be opportunities to correct the size and control sequences for equipment. Similar problems with size and control can also happen when areas of a building change function. If a system is too large, or delivers too much ventilation the tendency would be to leave it alone due to the impact on the first costs of a project.
An Example of incorrect sizing or incorrect sequences would be a lab space that had an extremely high number of air changes per hour (ACH) that has since been converted to office space. While the high number of ACH is not harmful to occupants, the cost to run the system is much higher than necessary.
In the near future I will post specific ECMs. In the meantime:
IF YOU KNOW OF A BETTER METHOD, LET ME KNOW!
Wednesday, June 6, 2012
BACnet MS/TP Wiring Recommendations
The two most common forms of BACnet communications channels that you are likely to encounter are BACnet MS/TP over RS-485 and BACnet/IP over Ethernet. Every device on a channel must use the same type of communications. To transmit data between channels of different types you must use a router.
1.) BACnet MS/TP - This channel is a 9.6 kbps - 76.8 Kps twisted pair channel. I/A Series BACnet controllers are delivered with MS/TP transceivers. I/A Series BACnet controllers (MNB-300, MNB-1000, MNB-V1, MNB-V2, etc.) must be on an MS/TP channel. MS/TP channels must be configured as a POLARITY sensitive RS-485 BUS topology.
The RS-485 BUS should use LOW IMPEDANCE 22 AWG or 24 AWG twisted shielded cable with a distributed capacitance between conductors of less than 15 pF/ft and a characteristic impedance between 100-130 Ohms. Belden 89841 is commonly recommended and can be used with confidence. I recommend that a maximum cable length of 2500' be observed.
2.) BACnet/IP - This is a TCP/IP channel. This channel is typically an Ethernet backbone from which other BACnet MS/TP channels are derived to create a network. Maximum cable lengths are subject to standard Ethernet wiring rules. 10/100 BaseT segments cannot exceed 328 feet.
Here is what I have been recommending:
Windy City Wire:
1-800-379-1191
BACnet MS/TP 24 AWG:
http://harrier.smartwire.com/ecom/invmainprof.php?item=042002-S
BACnet MS/TP 22 AWG (increased physical strength and works with ARCnet):
http://harrier.smartwire.com/ecom/invmainprof.php?item=043006AL-S
Belden 89841 is commonly recommended by manufacturers of BACnet equipment and can be used with confidence.
If you know of a better method, please let me know!
1.) BACnet MS/TP - This channel is a 9.6 kbps - 76.8 Kps twisted pair channel. I/A Series BACnet controllers are delivered with MS/TP transceivers. I/A Series BACnet controllers (MNB-300, MNB-1000, MNB-V1, MNB-V2, etc.) must be on an MS/TP channel. MS/TP channels must be configured as a POLARITY sensitive RS-485 BUS topology.
The RS-485 BUS should use LOW IMPEDANCE 22 AWG or 24 AWG twisted shielded cable with a distributed capacitance between conductors of less than 15 pF/ft and a characteristic impedance between 100-130 Ohms. Belden 89841 is commonly recommended and can be used with confidence. I recommend that a maximum cable length of 2500' be observed.
2.) BACnet/IP - This is a TCP/IP channel. This channel is typically an Ethernet backbone from which other BACnet MS/TP channels are derived to create a network. Maximum cable lengths are subject to standard Ethernet wiring rules. 10/100 BaseT segments cannot exceed 328 feet.
Here is what I have been recommending:
Windy City Wire:
1-800-379-1191
BACnet MS/TP 24 AWG:
http://harrier.smartwire.com/ecom/invmainprof.php?item=042002-S
BACnet MS/TP 22 AWG (increased physical strength and works with ARCnet):
http://harrier.smartwire.com/ecom/invmainprof.php?item=043006AL-S
Belden 89841 is commonly recommended by manufacturers of BACnet equipment and can be used with confidence.
If you know of a better method, please let me know!
Thursday, May 31, 2012
Subscribe to:
Posts (Atom)