Rooftop Packaged Unit With Economizer
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,Economizer HVAC Residential,Portable Rooftop with Economizer,Economizer Rooftop Packaged Unit Jinan Amrta Air Conditioning Co.,Ltd , https://www.amrtaac.com
Designed and constructed the Beijing Metro Lines 1 and 2 to open up the construction of urban rail transit in China, and presided over the preparation of China's first subway construction code, which has always been at the leading position in the field of subway construction. For decades, China’s urban rail transit construction has been It is closely linked to the name of a Beijing state-owned company. It is the Beijing Urban Construction Group.
During the construction of Beijing Metro Line 5, Beijing Urban Construction (600266) Group first introduced shield construction technology and formed a complete set of shield construction technology suitable for use in Beijing strata. “The design and construction technology of shield tunnels for Beijing Metro Line 5 "Research" won the "Beijing Science and Technology Progress Award."
Beijing Urban Construction not only successively took over major projects such as the subway lines 7, 8, 9, 10, 13, 14 and the South-to-North Water Transfer Project, but also maintained its leading position in the Beijing metro market, and the projects covered Tianjin, Guangzhou, Shenzhen, Hangzhou and Dalian. Zhengzhou and other large and medium-sized cities.
The Beijing Rail Transit Yizhuang Line Project undertaken by Beijing Urban Construction Group is Beijing's first BT project in the construction of rail transit. This project covers almost all methods of construction of rail transit construction from ground to underground, in the "ultra-small radius shield construction". The gap between the "overhead highway bridge suspension casting and turning construction", "400t beam erection technology", "through the existing cable (or highway) control technology" and other aspects to fill the gaps in the country.
Beijing Urban Construction Group's design consulting business has been accompanied by the growth of China's subway construction business. It has successively undertaken rail transit projects in more than 30 cities including China's first subway line (Beijing Subway Phase I and Phase II). Survey, design and consulting work; gradually developed into a large-scale integrated survey, design, and consulting company that takes the business of urban rail transit as its core strength.
Beijing Urban Construction Group is a promoter and leader in the development of technology in the field of urban rail transit engineering design in China. The picture shows the Wuxi subway designed by Beijing Urban Construction Group.
At present, Beijing Urban Construction Group undertakes the task of compiling or revising rail transit construction plans for a number of domestic cities, including Beijing, with a market share of over 50%; it has completed the feasibility of more than 50 urban rail transit routes in China. Sexual research work; 44 times commissioned by the National Development and Reform Commission to evaluate and accept the feasibility study of domestic urban rail transit projects.
As a facilitator and leader in the development of domestic urban rail transit engineering design fields, Beijing Urban Construction Group has successively compiled national standards such as “Design Code for Subways†and “Standard for Construction of Urban Rail Transit Projectsâ€, and has undertaken more than 30 cities and 66 projects. The general package of the urban rail transit line is designed, of which 36 lines have already been operated and the mileage of the route is 777 kilometers. Serialized high-end technological innovation has always made the design market share rank first in the country.
Beijing Urban Construction Group has formed a large number of core technologies with strong competitive advantages in professional fields such as sports venues. The picture shows the National Stadium constructed by Beijing Urban Construction Group.
This reporter learned that in addition to the subway traffic track project, the Beijing Urban Construction Group has formed a professional field in stadiums, airport terminals, large theaters, large museums, super high-rise buildings, roads and bridges, municipal utilities, and ancient gardens. A large number of core technologies with strong competitive advantages, a considerable part of which have reached the leading domestic and world-class level.
Today's Beijing Urban Construction Group not only continues to lead the construction of China's urban rail transit, but also builds on its reputation for having a large number of core technologies with market competitive advantages to create a corporate brand that enjoys national reputation. 
