Economizer with exhaust damper, fresh air damper, returan air damper and exhaust air damper. The dampers can be automaticlly controlled by PLC controller or by manual based on project needs.
This type HVAC system is another energy saving in the field of air conditioning.
Interlocked to run when return air dampers are being closed and supply air blower is in operation. The extraction fans run when outdoor air dampers are at least 50% open (adjustable). It is also overload protected. A gravity exhaust damper is supplied with this option to prevent air from entering the unit during shutdown.The power exhaust fans have been size to exhaust 50% of the nominal air flow of the unit.
The schematic diagram as below like free cooling system.
Rooftop Packaged Unit With Economizer Rooftop Packaged Unit With Economizer,Economizer HVAC Residential,Portable Rooftop with Economizer,Economizer Rooftop Packaged Unit Jinan Amrta Air Conditioning Co.,Ltd , https://www.amrtaac.com
April 16 Hangzhou Steel Market Price Quotes
Product Name Specification Material Steel Factory/Origin Price (yuan/ton) Yesterday Last Week Last Month Remarks General Line Φ6.5mm Q235 Xifeng 5060 0 10 100 Goods Less General Line Φ6.5mm Q235 Huaxinrui 5060 0 10 100 High Line Φ6.5mm Q235 Yong Steel 5220 0 20 140 High Line Φ6.5mm Q235 Ma Steel 5170 0 10 120 High Line Φ6.5mm Q335 Sanming 5170 0 10 120 High Line Φ6.5mm Q335 Haixin 5170 0 10 120 High Line Φ8mm Q335 Ping Steel 5170 0 10 120 High Line Φ8mm Q335 Jiyuan 5170 0 10 120 Rebar Φ10mm HRB335 Sha Steel 5120 0 -20 90 Rebar Φ12mm HRB335 Sha Steel 5040 0 -10 130 Rebar Φ14mm HRB335 Sha Steel 5020 0 0 130 Rebar Φ16-25mm HRB335 Sha Steel 5020 0 0 130 Rebar Φ10mm HRB335 Three yuan 4870 0 0 170 Rebar Φ12mm HRB335 Pinggang 4980 0 0 130 Rebar Φ12mm HRB335 Yonggang 5030 0 20 150 Rebar Φ16-25mm HRB335 Yonggang 5000 0 20 120 Rebar Φ16- 25mm HRB335 Ma Steel 5020 0 0 120 Less Rebar Φ16-25mm HRB335 Ping Steel 4920 0 -30 70 Rebar Φ16-25mm HRB335 Jiyuan 4900 0 0 120 Rebar Φ18-25mm HRB335 Egang 4900 0 0 120 Rebar Φ16- 25mm HRB335 Laiwu Steel 4900 0 0 100 25mm: Out of Stock Rebar Φ16-25mm HRB335 Xiwang/Yinfeng 4880 0 0 120 Rebar Φ16-25mm HRB335 Jigang Handan 4840 0 20 140 25mm:4870 Rebar Φ16-25mm HRB335 Jiangsu Hongtai 4840 0 20 140 25mm:4870 Rebar Φ16-25mm HRB335 Fuxin 4840 0 20 150 25mm:4870 Rebar Φ16-25mm HRB335 Zhongtian 4900 0 0 120 25mm:4920 Rebar Φ16-25mm HRB335 Jigang 5000 0 0 130 Rebar Φ16-25mm HRB335 Xicheng 4900 0 0 120 12mm:4920 Rebar Φ16-25mm HRB335 HRB335 Nanchang 4910 0 0 80 Rebar Φ16-25mm HRB335 Haixin 4900 0 0 120 Class III Rebar Φ12mm HRB400 Masteel 5100 0 50 210 Less Class III Rebar Φ16-25mm HRB400 Ma Steel 5080 0 30 210 28/32mm: 5280 Grade III Rebar Φ18-Φ25mm HRB400 Ping Steel 5020 0 20 140 25mm:5030 Grade III Rebar Φ18-Φ22mm HRB400 Yong Steel 5100 0 0 200 Grade III Rebar Φ16-Φ25mm HRB400 Jinan Iron & Steel 5100 0 0 200 Hot rolled coil 2.75mm*1250*C Q235 Hot/cold rolled steel 5550 0 0 150 Hot rolled coil 3.0mm*1500*C Q235 Angang 5500 0 0 150 Hot rolled coil 4.75mm*1500* C Q235 Angang 5430 0 30 250 Hot Roll 5.5mm*1500*C Q235 Handan Steel 5400 0 20 220 Hot Roll 7.5mm*1500*C Q2 35 Handan Steel 5380 0 10 210 Hot rolled coil 9.5mm*1500*C Q235 Handan Steel 5380 0 10 210 Hot rolled coil 11.5*1500*C Q235 Handan Steel 5380 0 10 210 Strip 2.75*150 DF01 Nangang 5350 0 50 70 Strip 2.75*180 DF01 Nangang 5350 0 50 70 Strip 2.5*183 Q195L Tangshan Jianlong 5230 0 30 200 Strip 2.5*355 Q195L Jilin Jianlong 5250 0 30 190 Strip 2.5*183 Q195 Tangshan Guofeng 5250 0 50 210 Strip 2.5*160 Q235 Tangshan Guofeng 5250 0 50 210 Strip 3.5*273 Q235 Tangshan Guofeng 5250 0 30 200 Strip 2.5*232 Q235 Tangshan Guofeng 5250 0 50 210 Strip 3.0*350 HG5 Hanggang 5350 0 50 70 Strip steel 3.0*200 HG5 Hanggang 5350 0 50 70 Cold rolled plate 1.0mm*1250*2500 SPCC Angang 6620 20 20 120 Cold rolled plate 1.0mm*1250*2500 ST12 Benxi Steel 6550 30 70 100 Cold rolled plate 1.0mm *1250*2500 ST12/DC01 Wuhan Iron and Steel Corporation 6550 30 50 50 Cold rolled steel plate 1.5mm*1250*2500 ST12/DC01 Wuhan Iron and Steel 6500 0 50 50 Cold rolled coil 1.0mm*1250*C SPCC Masteel 6550 30 50 130 Cold rolled coil 1.0mm *1250*C SPCC Handan Steel 6500 50 70 150 Cold Roll 1.5mm*1500*C ST12 Handan Steel 6480 30 50 130 Puzhong Plate 20mm Q235B Jinan Steel 6200 0 50 150 Puzhong Plate 8mm Q235A New/Magang Steel 6550 0 250 400 General Plate 10mm Q235A New / Magang 6250 0 50 150 Puzhong Plate 16-20mm Q235A New / Magang 6100 0 30 150 Low Alloy Plate 8mm Q345 New Steel 6550 0 0 100 Low Alloy Plate 10mm Q345 New Steel 6480 0 0 230 Low alloy plate 20mm Q345 New steel 6400 0 0 200 Boiler plate 8mm 20g Xinyu 7440 0 0 450 Boiler plate 10mm 20g Xinyu 7240 0 0 450 Boiler plate 14-25 20g Xinyu 6970 0 0 450 Container plate 8mm 16MnR Xinyu 7490 0 0 450 Container Plate 10mm 16MnR Xinyu 7290 0 0 450 Container Plate 12mm 16MnR Nangang/Xinyu 7020 0 0 450 Container Plate 14-25mm 16MnR Nansteel/Xinyu 7020 0 0 450 Seamless Tube 133*4.5 20# Hongdu 6500 0 0 0 Seamless Tube 168*8 20# Angang 6550 0 0 0 Seamless 219*6 20# Zhenda 6750 0 0 100 Seamless 273*7 20# Cheng 6950 0 0 150 I-beam 36#/b Q235 Laiwu Steel 5600 0 0 500 I-beam 40#/b Q235 Laiwu Steel 5600 0 0 480 Channel 16#a Q235 Masteel 5420 0 0 20 Channel 20# Q235 Masteel 5500 0 0 0 Angle Steel 50*50*5mm Q235 Tong Steel 5420 0 0 10 Steel 50*50*5mm Q235 Masteel 5500 0 0 50 Galvanized coil 0.6mm*1000*C ST02Z Steel 6650 0 0 0 Galvanized coil 0.7mm*1250*C ST02Z Steel 6640 0 0 40 Galvanized Volume 0.8mm*1 000*C ST02Z Angang 6600 0 0 50 Galvanized coil 1.0mm*1250*C ST02Z Angang 6430 0 0 30 Galvanized coil 0.5mm*1250*C DC51D+Z Masteel 6800 0 0 100 Galvanized coil 1.0mm*1250* C DC51D+Z Ma Steel 6450 0 0 50 Color Coil 0.40mm*1000*C SGCC Huang Shi Dongshan 7400 0 0 0 Color Coil 0.45mm*1000*C SGCC Huang Shi Dongshan 7350 0 0 0 Color Coil 0.50mm*1000* C SGCC Huangshan Dongshan 7100 0 0 0 Color Coil 0.426mm*1000*C CGCC Suzhou Xunxing 7300 0 0 0 Color Coil 0.476mm*1000*C CGCC Suzhou Xunxing 7200 0 0 0