Lighting Solutions

Lighting Solutions

Energy Efficient Fluorescent Lighting Solutions

Executive Summary

This section introduces the application of alternative technology options to contribute to the achievement of ‘best practice’ for energy efficient fluorescent lighting solutions.

Equivalent ‘Best Practice’ lighting standard for most commercial applications that meet Building Code of Australia requirements, is achievable:

Intelligent BMASS Power Saver voltage reduction technology

High performance magnetic ballasts (EEI B1 or B2)

Efficient Electronic Fluorescent Starters

Quality T8 Triphosphor Fluorescent Tubes

Quality fluorescent luminaire designs, including use of CFL luminaire

Complements other energy saving measures such as occupancy sensor, lighting zone management and automatic timers

Cost effective and energy efficient fluorescent lighting alternatives are readily available to the majority of commercial and Government customers.

Scalable energy efficient solutions are available now:

to suit most capital works or leasing budgets

to significantly reduce the cost of lighting upgrade or retrofit programs

to reduce current operational budgets

with potential for higher and immediate consumer uptake

T5 luminaire and especially T8 electronic ballast luminaire, are not the only solutions available to address important environmental concerns.

Overview

Ecospecifier, recently published a detailed technical analysis of a wide range of factors to be considered with regard to the performance of magnetic and electronic ballasts for fluorescent lighting, questions the 'electronic ballast or bust' drive currently in the marketplace, and provides highly cost effective strategies to reduce energy demand for lighting below the current leading standard ....“There is a seemingly strong case to review the single emphasis on the use of electronic ballasts, and to include the assessment of HP magnetic ballasts, used in conjunction with voltage reduction power saving units and electronic starters in project analyses and Green Star credits, to take energy savings in lighting to yet a new level of savings’….

A number of technology improvements associated with fluorescent lighting have occurred in recent years, particularly:

high performance low loss ballasts, both magnetic and electronic

T8 fluorescent tubes – triphosphor coatings, longer life, high efficacy and significantly reduced lumen depreciation

T5 fluorescent tubes – triphosphor coatings, smaller design, efficient and high output models

fluorescent starters – efficient electronic starters for use with magnetic ballasts

Power Saver – intelligent energy saving device, microprocessor controlled, superior build quality and electronics, higher capacities (older ‘dumb’ voltage reduction systems are no match)

The choices available for ‘best practice’ Energy Efficient Fluorescent Lighting Solutions decisions have never been more diverse. These technology enhancements are readily available but not all of the options are presented to customers. The T5 technologies, high frequency electronic ballasts and digital dimming technologies are well published but they do not fit all solutions and in many cases are not appropriate or just far too expensive for the majority of applications.

The Building Code of Australia dictates that a lighting system must achieve nominated watts per square meter (luminance power density) depending on the Building Classification and the nature of the use for the space that is being illuminated. In addition, the Green Star environmental rating system for office buildings is Australia’s first comprehensive rating system for evaluating the environmental design and performance based on a number of criteria, including energy efficiency.

Fluorescent Tubes

Models

T12 - obsolescent monophosphor / halophosphor gradually replaced with T8 tubes; low efficacy, short life and high lumen depreciation

T8 Halophosphor - low efficacy, short life and higher lumen depreciation

T8 Triphosphor - increased lumen output with many available options, significantly increased efficacy and tube life, and significantly reduced lumen depreciation

T5 Triphosphor - smaller tube size and reduced wattage, high efficiency (HE) and high output (HO) models with T5 tubes either more efficient (HE) or brighter (HO) but never both at the same time, increased efficacy and tube life, and significantly reduced lumen depreciation

CFL - dedicated CFL luminaire with ballast and lamp socket integral, energy efficient option for replacement of inefficient halogen down lights; screw/batten base self-ballasted CFL to replace incandescent lamps (mostly domestic use)

Environment

Ambient temperature has a significant affect on lamp output. The optimum temperature for T8 is 25°C and T5 is 35°C. Consequently, T5 perform better in enclosed luminaire than open or suspended.

Luminaire

Varying designs and manufacturers for all tube and ballast combinations

Choice of luminaire has significant impact on lighting effectiveness:

efficiency of the lighting scheme to deliver the light to the working plane

AS1680 series of Standards - quality and quantity of interior lighting

quality luminaire available for T8 and T5 tubes

Luminaire Ballasts Options

All fluorescent lamps are operated with a ballast to initiate discharge at well defined voltage and current. They are responsible for pre-heating the lamp electrodes, for sufficient ignition voltage, and limiting lamp current. Two types of ballast, magnetic and electronic.

T8 luminaire can be fitted with:

Electronic - high frequency operation avoids most perceptible flicker, improved lamp life and system efficacy, integrated lamp ignition (no starter), contains hazardous waste, and shorter life and less reliable than modern magnetic. Three categories available: EEI A1 - dimmable ballast with same efficiency as A3, EEI A2 - high performance and warm start feature, and EEI A3 - low performance and no warm start.

Magnetic - operate at mains frequency, low energy loss but slightly higher than A category, cathode warm start, extreme long life and reliability, automatic cut-off of cathode heating, fully recyclable and no hazardous waste. Two categories available: EEI B1 - high performance, low energy loss, highest reliability and life, 'A' noise rating, reduced flicker (improved filters), EEI B2 - high performance, lower energy loss, highest reliability and life, 'A' noise rating, reduced flicker (improved filters), and meet MEPS standards for use in Australia/NZ.

Common Magnetic - old standard ballasts, reliable and long life but less efficient and higher energy consumption/loss. EEI C and D obsolete technology but still common. No longer sold in Australia/NZ as below MEPS standards for new installations. Energy efficiency can be greatly improved with use of BMASS Power Saver, energy loss reduced by >60% and replacement is not essential in existing installations.

Electronic Fluorescent Starters - magnetic ballasts only

provide most of the benefits of electronic ballasts, except high frequency operation

optimum pre-heat time for warm tube start and maximum tube life (pre-heating is essential to reduce the wear effect of normal starting procedures)

absolute flicker free and smooth start of fluorescent lamps with no multiple starting attempts (even at reduced supply voltages and temperatures down to minus 20°C)

T8 fluorescent tube life is at least doubled

automatic shut-off of defective lamps

automatic safety shut-down, full thermal and constant circuit safety monitor

very low EMI during start

no residual current unlike glow starters

20 year expected life

ideal for use with BMASS Power Saver, but not essential

Glow / Flicker Starters

inexpensive starters normally supplied with tubes and luminaire

inefficient starting of fluorescent tube

characterised by blackening at the end of tubes from multiple starting attempts

characteristic flickering on start and failure

most published system comparisons of magnetic versus electronic assume inefficient glow starters are installed

All T5 luminaire are fitted with a specific type warm-start electronic ballast

must have cut-off technology for safety and protection of other luminaire components due to failing T5 tubes

warm-start for improved tube life

Dedicated CFL Luminaire

CFL luminaire are either magnetic (pre-heat or rapid start) or electronic ballast

some electronic ballast are dimmable

no MEPS for dedicated CFL luminaire (only self-ballasted screw/batten type)

Ballast Factor (BF) - all luminaire supplied with manufacturers BF rating

BF is a measure of the ability to produce lumen output for a specific lamp/ballast system relative to the rated lumen output; generally electronic are 1.0 and modern magnetic are 0.94

it is not specifically a measure of energy efficiency

Ballast Power Factor

Ballast Power Factor is a measurement of how effectively it converts voltage and current supplied by the power source into watts of usable power delivered to the ballast, measured as a value between 0 and 1

High Power Factor (HPF) ballasts have a value of 0.9 or greater. Ballasts below 0.9 are called Normal Power Factor (NPF). A good power factor is considered to be greater than 0.85

all electronic ballast are HPF

all recent high performance magnetic ballasts B1 and B2 are HPF ballasts

BMASS Power Saver - Voltage and Current Reduction Technology

BMASS Power Saver is a voltage reduction device. It reduces the power demand of fluorescent lamp fittings by reducing the load voltage and current, with a resultant improvement in power factor.

Power savings are achieved by reducing the voltage to the fluorescent lamp fitting by approximately 15% (240v - 206v relative to supply voltage) which in turn reduces load current by 20 - 30%. It results in a reduction of power consumed by a theoretical 33%, in practice, energy savings of around 30% are regularly achieved.

Voltage reduction is only applied after the efficient start of tubes at full voltage and current, ensuring no loss of tube life (automatically controlled through its onboard microprocessor).

Voltage reduction results in an increase in lighting efficiency (lm/w) of >20%, enabling a significant reduction in supplied power/energy (w) with no perceptible loss in lumens (normally under 10%).

Not suitable for use with electronic ballasts as they are designed to maintain a constant wattage, and will increase the current when voltage is reduced to compensate.

The key advantages of voltage reduction techniques, are:

power / energy consumption reduced by up to 33%

energy loss reduced by >60% across all magnetic ballasts

light efficiency / efficacy increased by >20% at reduced voltages and currents, making it possible to reduce power

reduced EMR emissions

reduced stress on tube assembly due to flicker free operation and reduction of voltage/current across the lamp after start-up

reduced heat emission from ballast and lamp fitting

Energy Saving

Consumers are normally billed based on the amount of power consumed in kilowatt-hours (kWh). Additionally, non-domestic consumers may pay a fee as a ‘demand charge’ based on the volt-amperes (VA) that a utility company must have available should the consumer activate all of its requirements at once, such as the beginning of a workday.

Consumers generally can reduce their power consumption by:

improving the total efficiency of their systems over time with high power factor (HPF) equipment – in order to reduce the ‘demand charge’ component of their bill (based on kVA)

incorporating measures to reduce actual power consumption (kWh)

Energy efficiency relates to the total power consumption (fluorescent tube, ballast and luminaire combined) expressed in watts.

Fluorescent tubes are available in many wattages, and vary between the T5 and T8 models.

The maximum permitted power consumption of a ballast and tube by energy efficiency category is detailed in AS/NZ Standard MEPS for Fluorescent Lamp Ballasts. Categories that meet the Australian/New Zealand standard are EEI A1, A2, A3, B1, and B2 where A designates electronic ballast and B designates magnetic ballast.

A combination of electronic ballast and T5/T8 tube limits any additional energy savings as they are designed to maintain constant wattage. The exception is dimming with A1 ballasts (limited applications and expensive to install). T5 HE (not T5 HO) requires less energy due to their lower wattage but produce slightly less lumen than a quality T8 luminaire.

A combination of T8 tubes and B1 or B2 magnetic ballasts will enable significant additional savings in energy consumption (kWh), beyond the energy efficiencies already achieved against traditional obsolete C/D ballasts. Application of Power Saver, through voltage and current reduction, will result in:

Power (kWh) savings up to 33%

Reduction in Power Density (watts/m²)

Reduction of ballast energy loss typically by >60%

Reduction in heat generated by luminaire – reduced load on air conditioning system

Increased tube and ballast life – less stress on tube and ballast

Optional use of electronic starters to more than double tube life due to efficient warm start process, stop tube flickering, significantly reduce maintenance costs associated with tube and starter replacement

Indicative Energy Savings for Tube/Ballast Combinations

Energy Savings for Ballast Systems	Indicative Energy Savings (Watts)
	Replacement Luminaire Ballast Type					T5 HE A1	Power Saver
	B2	B1	A3	A2	A1	T5 HE A1	Power Saver
D (46W)	7%	11%	17%	22%	17%	26%	≤ 33%
C (45W)	5%	9%	15%	20%	15%	24%	≤ 33%
B2 (43W)	-	5%	9%	16%	9%	21%	≤ 30%
B1 (41W)	-	-	7%	12%	7%	17%	≤ 30%
A3 (38W)	-	-	-	5%	0%	10%	-
A2 (36W)	-	-	-	-	- 5%	5%	-
A1 (38W)	-	-	-	-	-	10%	-

Notes:

1. Figures derived from AS/NZ Standard MEPS – Fluorescent Lamp Ballasts, based on standard T8 36W and T5 28W HE fluorescent tubes. Actual figures may vary between the many product manufacturers but must not exceed the system wattage consumption figures used.

2. All B2, B1, A3, A2 and A1 ballasts are available as High Power Factor (HPF) ballasts.

3. A1 ballast figures are without dimming. A1 dimming can reduce the lumen output by up to 50% but is not suitable for many applications.

Luminaire Energy Efficiency

Luminaire energy efficiency needs to consider the combination of:

Optic reflector – significantly affects ability to deliver light to work area (glare reduction is also required for T5 tubes)

Mounting method – surface, recessed or suspended (significant for T5 tubes as can affect efficacy/lumen output due to ambient temperature)

Ballast type – all new ballasts are now HPF and low energy loss

Fluorescent tube – many lumen options available, especially for T8

Light Output Ratio (LOR) and Spacing to Mounting Height Ratio (SHR). LOR is a measure of the quantity of light emitted from the luminaire, as compared to the lamp itself. Where the light absorption within the luminaire and the change in light output due to the thermal conditions within the luminaire are considered, it is known as the LORL or Light Output Ratio Luminaire. LORL is generally used in Australian photometric reports provided by manufacturers for their luminaire. SHR is a factor used to achieve uniformity of illuminance in the lighting design; relates to the spacing of the luminaire, to the mounting height of the luminaire.

All 36W or equivalent high performance ballasts (magnetic and electronic) are available as High Power Factor (HPF) ballasts – reduces VA demand.

Importantly, the energy efficiency of any luminaire fitted with high performance magnetic ballasts is significantly improved with the use of Power Saver.

Utilisation Factor - measures the efficiency of the lighting scheme to deliver the light to the working plane relative to the room/environment where the luminaire are operating. It incorporates the Light Output Ratio (LOR) and the proportion of lumen reaching the working plane from both direct and reflected off other surfaces encasing the room/environment (ceiling, walls, and floor).

The following table provides examples of different combinations within the luminaire. It is very important to note that the choice of an efficient combination of optic reflector and mounting method impacts on the overall luminaire energy efficiency, irrespective of the chosen ballast/tube. The table also includes the estimated additional energy efficiency achievable with the installation of Power Saver with T8 - B1 magnetic ballast luminaire in these examples; lighting scheme power density watts/m². The table samples are not intended to represent the most energy efficient combination, but to highlight that just because it is has a T5 tube or a T8 electronic ballast does not automatically mean you have the best lighting solution.

BMASS Power Saver has been pre-assessed by ECOSPECIFIER as a product likely to contribute to the achievement of Green Star credit points against the Green Star environmental rating system for buildings – Green Building Council of Australia (GBCA) and meeting significant energy efficiency criteria using the Australian Building Greenhouse Rating (ABGR) scheme by office building owners and tenants. In particular, the following energy efficiency categories:

Office Interiors

Office Design

Office As Built

Office Existing Building

The table below highlights the Office Lighting Power Density (watts/m²) improvements possible with the installation of Power Saver, equalling the available Green Star credit points of the best of any luminaire combination in the examples presented at the inaugural Greenlight Australia Conference, 22 Mar 2007 co-hosted by Lighting Council of Australia and Australian Greenhouse Office.

Click for Enlarged View

Notes:

1. Ballast Factor (BF) for all A2 ballast is 1.0 and B1 ballast 0.94.

2. Initial lumen figures are T5 – 2600, T8 A2 – 3200 and T8 B1 – 3350.

3. Utilisation Factor (UF) – varies significantly between luminaire optic design and mounting method, affecting the overall luminaire efficiency; higher UF gets a better result irrespective of the type of ballast.

4. Conservative estimates based on a minimum wattage saving of 26% and a maximum lumen reduction no more than 10%.

5. Lighting Council of Australia is examining a 5 Star Rating Scheme for luminaire – similar to European Union/USA approach – lowest 1 to highest 5.

Luminaire Total Efficacy

Some of the factors that should be considered in determining the luminaire total efficacy are as follows:

Efficacy of the light source – ambient temperature should be considered for T8 versus T5 luminaire (25 – 35 °C)

Efficiency of the control gear (high performance magnetic or electronic); in particular ballast factor (B1/B2 - 0.94 and A - 1.0)

Photometric efficiency of the fitting – includes ability to deliver lumen and not absorb a high percentage of emitted lumen from tubes

Useful lumens, defined as the efficiency of the lighting scheme to deliver the light to the working plane relative to the room environment; includes consideration of direct and reflected light

Total system wattage – total circuit power of lamps and control gear; Power Saver efficiencies should be considered when calculating the total system wattage

Not easily calculated without software tools, and these tools do not incorporate the features of Power Saver technology. The total system power should be reduced by around 25-30% in any calculations and will significantly alter/improve luminaire efficiency of those fitted with B1 ballasts: particularly, watts/m²and associated Green Star credits, and any possible Star Rating

T5 Adaptors and Inserts

T5 retrofit devices are available for existing T8 and T12 lamps. T5 tubes are shorter and only operate with electronic ballasts at standard voltages, and require either an adaptor or complete insert to operate. Some T5 adaptors claim an energy classification of EEI A3.

These devices have integral electronic ballast and bypass the normal starter operation. The existing magnetic ballast still draws some power as it is not disconnected. T5 insert devices, as opposed to adaptors, can be installed in T8 electronic ballast lamps but require an electrician to bypass the existing ballast circuitry.

Energy savings (watts) of around 32% are claimed against old T8/12 EEI D ballast systems.

All T5 adaptors and inserts are designed to replace a single lamp. The indicative cost of T5 adaptor system is a minimum of $50 per tube, based on:

T5 adaptor - $35-45 per replaced tube

T5 fluorescent tube - $16-23 each

No data is readily available on Luminaire Energy Efficiency and the use of T5 adaptors and inserts. Some T5 insert products can be supplied with optional reflectors and diffusers at an extra cost.

In summary:

Very high cost option at $51-$68 per tube

No additional energy savings to justify the high cost

Ongoing maintenance/replacement costs of adaptor uncertain – provided with a 2 year warranty

Adaptors are a potentially simple option for very small installations

Complete technical guide on Energy Efficient Fluorescent Lighting Solutions

Click here to download.