In Part I and
II of this series [1, 2], we presented the data on 400W single
ended mogul reflectors, designed primarily to be retrofit
into existing canopies, and 250W Double ended reflector fixtures.
This article continues in a similar vein and presents the
data and analysis of several additional reflectors that we
were able to obtain since the last set of tests.
Table
1: Listing of the Reflectors Tested
Reflector
Ballast
Lamp
PFO
Illuminator
Magnetic
Ballast (M59)
Ushio
400W 10000K
SuperSun
IV - Sunlight Supply
Magnetic
Ballast (M59)
Ushio
400W 10000K
Reef
Optix I - Sunlight Supply
Magnetic
Ballast (M59)
Ushio
400W 10000K
Small
Diamond Light
PFO
HQI Ballast (M81)
Vion
250W 10000K
Regent
DIY 150W Double Ended
Reliable
Ballast (electronic)
AB
150W 10000K
Giesemann
250W Nova II
Giesemann
Ballast (electronic)
AB
250W 10000K
Giesemann
150W Nova II
Giesemann
Ballast (electronic)
AB
150W 10000K
PFO's Illuminator
and Sunlight Supply's SuperSun are designed primarily for
horticulture use, but given that we tested the Diamond Lighting's
Lumen Arc III which is also a reflector designed for horticulture
applications, we felt it would be interesting to test a few
other horticulture reflectors. Diamond Light also makes a
smaller reflector (called LA3) which is more suited for 250W
single ended mogul lamps (it does not accommodate the 400W
lamps as they are too long to fit in this reflector). The
small Diamond Light reflector's results are also shown here.
Unfortunately, when this reflector was tested the only available
250W lamp on hand was a Vion 250W lamp (not the best lamp
in its class and is no longer being sold). So this data cannot
be directly compared to the 10000K lamps and reflector systems,
however, the % distribution plots of this reflector would
provide useful data for comparison purposes.
Proud
sponsor of this column
The two Giesemann
Nova II fixtures are also a choice available to the discerning
aquarist especially those interested in aesthetically pleasing
designs and good quality, and these reflectors are also tested
here.
As avid DIY'ers
ourselves, we also explored a cheap version of the 150W double
ended reflector system made by retrofitting a Regent 500W
Halogen lamp fixture. The allure of this fixture is the fact
that it can be easily purchased at Lowe's or Home Depot for
about $10, and with a small retrofit of replacing the halogen
sockets with the sockets for the 150W double ended lamps,
one could make a very cheap reflector for about $20 and change.
The basic methodology
and experimental setup is identical to the one used in the
previous set of articles (part I and II, references [1] and
[2]). The data is also presented in an identical manner with
plots for light dispersion for each reflector at distances
of 6", 9" and 12" from the center of the lamp. This article
is intended to be a continuation of the previous articles
and hence should be read in conjunction with the other two
articles.
Reflector
Data and Analysis
The data plots
for each reflector at the distances 6", 9", and 12" are plotted
as a surface graph, top view graph, and a % distribution graph
to illustrate the intensity and spread at different points
on the measuring grid. Table 2 below shows the list of figures
associated with each reflector.
Table
2: List of Figures associated with each reflector
Reflector
Figures
PFO
Illuminator
Figs.
1-3
SuperSun
IV - Sunlight Supply
Figs.
4-6
Reef
Optix I - Sunlight Supply
Figs.
7-9
Small
Diamond Light
Figs.
10-12
Regent
DIY 150W Double Ended
Figs.
13-15
Gieseman
150W Nova II
Figs.
16-18
Gieseman
250W Nova II
Figs.
19-21
One of the measures
of a reflector performance could be its ability to direct
light into the aquarium. A reflector's total incident light
upon a surface of a given area is representative of the performance
of a reflector. It is computed by adding up all the measurements
taken at the discrete points within the region. It demonstrates
how much light the reflector is able to focus downward when
compared to other reflectors with similar operating conditions
(same ballast and lamp). While it can be argued that adding
all the PPFD values is technically not a valid measure as
per the definition of PPFD (since PPFD is defined as microEinstiens/m2/sec),
it can be used to provide a metric for reflector performance.
Further summing over the data points on a given area can easily
be used to compute the average, if so desired. Since the area
under consideration is the same for all reflectors, we can
just as well use the sum of the PPFD values distributed over
this area (169 data points) instead of an average as a performance
metric.
Table 3 presents
this data for the reflectors in this article.
Table
3: Total Incident PPFD on a given Surface area
Total
Incident Light
Reflector:
Distance:
3x3
Area
2x2
Area
1x1
Area
Maximum
PPFD:
PFO
Illuminator
6"
45388
43285
31140
2147
9"
44385
37609
21809
1270
12"
39631
30759
14603
755
SuperSun
IV - Sunlight Supply
6"
44585
43867
32103
2150
9"
44326
39437
22892
1285
12"
41449
33108
16279
860
Reef
Optix I - Sunlight Supply
6"
44223
42290
30168
2547
9"
41082
35476
22486
1793
12"
39887
32318
18703
1317
Small
Diamond Light
6"
27308
26700
21857
1698
9"
24705
22616
15519
1000
12"
23837
20854
12185
685
Regent
DIY 150W Double Ended
6"
17046
17046
14985
1706
9"
16058
16058
10854
815
12"
13854
13854
7717
465
Giesemann
250W Nova II
6"
32085
31875
28454
3360
9"
31479
30400
20502
1513
12"
30618
26931
16571
887
Giesemann
150W Nova II
6"
15715
15596
14048
1683
9"
15404
14722
10159
754
12"
14901
12898
7144
418
As can be seen
from this data, the 2 horticulture reflectors (PFO Illuminator
and Sunlight Supply's Super Sun IV) and the Reef Optix are
very similar in performance. We have found that reflectors
with the ends closed tend to perform better. The Giesemann
Nova II fixtures, while very aesthetic and thoroughly designed,
could benefit specifically from improved reflector design.
In addition to
knowing how much light is incident on a given area, we could
also look at how much loss of light occurs on a given area
when moving the lamp and reflector higher. Table 4, presents
the % of light lost on a specified area as one moves the lamp/reflector
from 6" to 12" above the surface. A higher % loss would indicate
that the reflector is creating a larger spread.
Table
4: Percent of PPFD lost from 6" to 12" from the lamp
3x3'
Area
2x2'
Area
1x1'
Area
PFO
Illuminator
13
30
53
SuperSun
IV - Sunlight Supply
7
25
50
Reef
Optix I - Sunlight Supply
10
24
38
Small
Diamond Light
13
22
44
Regent
DIY 150W Double Ended
19
19
49
Giesemann
250W Nova II
5
16
42
Giesemann
150W Nova II
5
50
49
Another metric
to analyze reflector performance could be to determine the
area coverage of a specified amount of light. Although it
is difficult to determine exactly what this specified minimum
PPFD values should be, we have chosen a cut off of 500 PPFD
and present the area coverage plots of each of the reflectors
in Figures 22,23, and 24.
Figure
22
Figure
23
Figure
24
Conclusion
This article is
the 3rd in this series and presents the data and
a brief analysis of several additional commercially available
reflectors. The data provided shows clearly the differences
between the reflectors, and can provide the reader with useful
data on the light distribution patterns and shapes, which
in turn can be used for purposes of aquascaping and placement
of corals.
Acknowledgements
We would like
to thank several people whose help made this study possible.
They were kind enough to provide us with lamps, reflectors
and ballasts for testing: Patrick at PFO Lighting, Brad at
Sunlight Supply, Phil at Xenia Inc. for the Giesemann fixtures,
Shane Graber for the use of his small diamond light reflector,
and Brian at Hellolights.com.
