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CSR Edmonds Technical Centre PO Box 511 Brookvale, NSW 2100 ph: 8978 6555
Page 1 of 16
TEST REPORT
REPORT NO. 26-11-09
TESTING OF ECOPOWER 400 UNDER EXCESSIVE HEAT CONDITIONS Physical tests have been conducted to investigate the cooling capacity of an ecopower
400 operated under excessive internal thermal and dynamic weather conditions on a small building enclosure.
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 2 of 16
Report No: 26-11-09
Report Date: 26 November 2009
Part 1 -AIR FILTER RESISTANCE TESTING
Aim: To define appropriate sizes and types of airfilters which could maintain
required indoor temperatures in a small building ventilated by an ecopower
400 operated under excessive internal heat and external dynamic weather
conditions.
Introduction: An airfilter on the air supply inlet creates an additional amount of static
pressure a fan must overcome. This pressure drop across an airfilter in this
application should be measured as air is sucked through an airfilter at a
given air velocity. However, CSR Edmonds does not have the appropriate
facilities at hand to conduct this type of experiment. An alterative existing
experimental set up for measuring pressure drop when air is blown through
the filter has been used. In this situation, an airfilter creates an obstruction to
the flow of air and this static pressure drop adds the impedance to the
system which works to resist the flow. These tests do not comply with
standard procedures and can be used only for indoor investigations.
Customer: External (“Ventfair”, Germany)
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 3 of 16
Test methods and specifications
The tests have been conducted on inhouse experimental facilities situated
within the Research and Development Department of CSR Edmonds on 12-
30 November 2009.
The equipment used for measuring the pressure drop of the filter units is
shown in figures 1. It is an inlet side test chamber fan test rig built in
accordance with ISO 5801 (clause 26.10 and 70 b)). It has an inlet orifice
plate with piezometer ring corner taps for flow rate determination. The inlet
duct diameter is 400mm with the chamber hydraulic diameter being
1000mm.
Figure 1 –Experimental set up
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 4 of 16
Figure 1 –Experimental set up (continuation page)
The grille assembly SK 3326.207 (Rittal) with an airfilter (1) to be tested was
mounted to a face plate at the end of the chamber as is shown in Figure 1.
This filter has an area of 250x250mm. Figure 2 depicts the grille assembly
and used dirty Rittal filter element. Four different types of airfilters Rittal, G2,
G3 and G4 have been tested for comparison.
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 5 of 16
Figure 2 –Grille assembly and dirty Rittal filter element
Test for all filters at a range of flow rates were conducted with
measurements of the following made.
-the differential pressure across the orifice plate for flow determination;
-the differential pressure between atmospheric and chamber pressure for
pressure drop determination.
Several readings were taken to obtain an average value.
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 6 of 16
The obtained values of downsteam pressure have been converted into the
air flow rate as it described in ISO 5801(clause 26.10).
Test results Figure 3 provides an indication of the resistance of the various filter elements
as a function of the flow velocity across the filter.
0
10
20
30
40
50
60
70
0 0.5 1 1.5 2 2.5
Air velocity (m/s)
Pre
ssu
re d
rop
(
Pa)
Rittal filter
Empty grille assembly
G3
G4
G2
Dirty Rittal airfilter
Poly. (G4)
Poly. (Empty grille assembly)
Poly. (Dirty Rittal airfilter)
Poly. (G2)
Figure 3 – Air filter resistance
Clean air resistance
0
20
40
60
80
100
120
140
160
180
200
1800 2800 3800 4800 5800 6800 7800 8800 9800
Air flow rate (m3/hour)
Pre
ssu
re d
rop
(P
a) G2
G3
G4
Poly. (G4)
Poly. (G3)
Poly. (G2)
Figure 4 – Characteristics of airfilters (Source: ASHRAE 52.1-1992 or EN 779)
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 7 of 16
It can be seen from Figure 3 that the change in pressure drop for G3 is very similar to the pressure drop for the Rittal airfilter. For further experiments it was assumed that the Rittal airfilter is identical to G3. The pressure drop across G3 can be defined from ASHRAE 52.1-1992 or EN 779 as is shown in Figure 4. The comparison between Figure 3 and Figure 4 reveals that all functions obey a parabolic law and the highest pressure drop across the airfilter corresponds to G4 and the lowest value was found for G2. Assuming that there are correlations between these two situations, the pressure drop across the grille assemblies unit can be found from Figure 3 by multiplying the values from Figure 3 on the corresponding correlation function. Actual flow rates for tested solutions can be found from Figure 5. The highest value of air flow rate of 1080 m
3/hour was found to be for an empty
grille assembly with no filter element and the lowest value of 220 m3/hour for
a used dirty Rittal filter.
0
10
20
30
40
50
60
70
0 500 1000 1500 2000 2500Flow Rate (m3/hr)
∆p
(P
a)
Ecopower perfomance curve
Rittal filter
Dirty Rittal filter
G3
G2
Empty grille assembly
G4
Poly. (Dirty Rittal filter)
Poly. (G2)
Poly. (Rittal filter)
Poly. (G3)
Poly. (Empty grille assembly)
Poly. (G4)
Figure 5 – Performance curve of Ecopower 400
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 8 of 16
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 9 of 16
PART 2 –AIR FILTER BUILDING TESTING
Aim: Assess the performance of the ecopower 400 to remove excessive internally heat for different levels of inlet area resistance under various climatic conditions
Customer: External (“Ventfair”, Germany)
Test methods and specifications
The building is designed for the purpose of comparing various insulation/ventilation solutions. The building contains various monitoring equipment, including type K thermocouples and Vaisala Temperature and humidity Probes. The data is recorded using Datataker DT 85’s. The buildings can be seen in Figure 6 below.
Figure 6 -Testing building
The building wall section is shown in Figure 7.
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 10 of 16
Figure 7- Testing building wall section
The building faces north with a roof pitch of five degrees. The building external dimensions are 2120mm wide x 2120mm long and 2450mm high on the tallest side. The ecopower 400 ventilator (CSR Edmonds) and the T5 400 mm damper (CSR Edmonds) were fitted to the roof. Two electric oil heating radiators (De’Longi) were placed in the building. Heat output of each radiator was 1.5 kW. During this testing time, the average heat output was 2.8 kW. One of the heaters turned off for short periods of time during the day as it had reached its internal thermostat set point. This reduced the average heat output from 3.0kW to 2.8kW.
Figure 8 – Testing building
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 11 of 16
Figure 9- The Ecopower 400 and the T5 400 mm damper
Two filter units SK 3326.207 (Rittal) were installed into the inlet area . From the 15 October to 28 October, airfilters have been installed into the grille assemblies (first airfilter solution) and from the 28 October to 23 November experiments have been conducted with one empty grille assembly and one section with installed airfilter (second airfilter solution).The indoor environment has been analysed for different levels of solar radiation and ambient temperatures. Schematics of the testing assembly are shown in Figure 8 and Figure 9. Actual flow rates for both solutions can be estimated from graph 11, for first airfilter solution actual flow rate is 685 kg/hour and for second is 1000 kg/hour. The parameters being measured:
- Interior and exterior wall temperature, for every wall and roof - Interior air temperature of the building - Interior air relative humidity of the building - Ambient temperature (outside) - Interior inlet temperature (near the ventilator throat) - Interior outlet temperature (near the inlet area) - Wind speed (measured in 20 second intervals and averaged for every
5 minute time cycle) - Solar radiation
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 12 of 16
0
10
20
30
40
50
60
70
0 500 1000 1500 2000 2500
Flow Rate (m3/hr)
∆p
(P
a)
Ecopower perfomance curve
2 Airfilters
2 Grille sections
1 grille section + 1 filter
Dirty Rittal airfilters
Poly. ( 2 Grille sections)
Poly. (2 Airfilters)
Poly. (1 grille section + 1 filter)
Poly. (Dirty Rittal airfilters)
Figure 11 – The performance curve of Ecopower 400
The data was logged continuously over the period 15 October 2009 – 23 November 2009, in 5 minute intervals.
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 13 of 16
Test results
The below charts illustrate the internal thermal behaviour of the building for the different levels of solar radiation and ambient temperatures.
Indoor temperature readings
20
22
24
26
28
30
32
34
36
38
40
0 100 200 300 400 500 600 700 800
The level of solar radiation, W/m2
Inte
rnal te
mp
era
ture
, d
eg
C
Average
Maximum
Minimum
Figure10 Internal temperature vs solar radiation for first airfilter solution (2 Rittal air filters)
Indoor temperature readings
20
25
30
35
40
45
0 100 200 300 400 500 600 700 800
The level of solar radiation, W/m2
Inte
rnal
tem
pera
ture
, C
Average
Maximum
Minimum
Figure11 Internal temperature vs solar radiation for second airfilter solution (1 Rittal air filter and 1 empty grille)
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 14 of 16
.
Average internal temperature readings
26
27
28
29
30
31
32
33
34
0 100 200 300 400 500 600 700 800
The level of solar radiation, W/m2
Inte
rnal te
mp
era
ture
, C
1 airfilter & 1 empty grille
2 airfilters
Linear (2 airfilters)
Linear (1 airfilter & 1 empty grille)
Figure12 Average internal temperature readings for both solutions vs solar radiation
Indoor temperature readings
15
20
25
30
35
40
45
15 17 19 21 23 25 27 29 31 33 35
Ambient temperature, deg C
Inte
rnal te
mp
era
ture
, d
eg
C
Average
Maximum
Minimum
Figure 13- Internal vs ambient temperature for first air filter solution (2 Rittal air filters)
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 15 of 16
Indoor temperature readings
15
20
25
30
35
40
45
50
15 20 25 30 35 40 45
Ambient temperature, deg C
Inte
rnal te
mp
era
ture
, d
eg
C
Average
Maximum
Minimum
Figure 14 Internal vs ambient temperature for second filter solution (1 Rittal air filter and 1 empty grille)
Average internal temperature readings
20
25
30
35
40
45
15 20 25 30 35 40 45
Ambient temperature, deg C
Inte
rnal te
mp
era
ture
, d
eg
C
1 filter
2 airfilters
Figure 14 Average Internal temperatures for both airfilter solutions vs ambient temperature
CSR Edmonds Technical Centre
Unit 1/93-99 South Creek Road Dee Why, NSW 2099 ph: 8978 6500 Page 16 of 16
Discussion
Testing of one empty grille (without filter element) and another grille with filter fitted was undertaken to increase flow rates. The increased flow rate through this removal of one of the filter element and leaving one element in place is equivalent to fitting 4 Rittal filter elements of this size (250x250mm each, 0.0625m2). As it can be seen from Figures 10-12, indoor temperature slightly increases with increasing level of solar radiation and it can be approximately correlated by a linear function. The linear curves have different slopes which indicate that second airfilter solution in the comparison with first air filter solution provides more stable thermal indoor environment due to a lower gradient. Figures 13,14 and 15 further reinforce that the indoor temperature is higher for the first airfilter solution and both curves linearly correspond to ambient temperatures. Obviously higher flow rates improve the heat removal rate and help maintain lower internal temperatures. Roughness of the first solution graphs indicate that not enough data has been collected to be certain of the results and reach definite conclusions. However it can be seen that for the most part internal temperatures are able to be kept below 35°C except during high ambient temperatures above around 30°C.
Conclusions The tests show that temperatures can mostly be kept below 35°C except during high ambient temperatures above 30°C. It is recommended that a minimum of four Rittal filter elements (G3 equivalent) with a total area of 0.25m2 (0.0625m2 each) be used. Further field testing in the actual applications is recommended to confirm these results.
Test officer: Tatiana Kivva