1.　　SCOPE OF WORK (前言)

Furniture supplier shall be responsible for final connection of Fume Hood, canopy hood, vents of acid, flammable cabinets, and shall be communicating with HVAC contractor for air exchange volume, air exchange rates to meet lab safety requirement.
實驗室家具承包商將負責抽風柜，排風罩和酸堿柜等排風點的最后連接，并負責和空調及排風系統的承包商確定實驗室區域的排風量，換氣頻率等具體技術要求，確保實驗室的安全。

2.　　GENERAL (綜述)

2.1　　The laboratory exhaust system includes exhaust duct works, exhaust fan, laboratory fume hood exhaust, laboratory canopy hood and cabinets needed venting.
實驗室排氣系統包括排氣管路、排氣風機、實驗室通風柜管道、實驗室排風罩和特殊存儲柜的排氣管道。

2.2　　　　Some specified scrubber(s) to treat toxic or hazardous gases should be provided at the end of exhaust system and the concentration of exhaust gas should be meet the CCIQ policy. This part shall be responsible by HVAC contractor.
對有毒、危險氣體的排氣管路末端有空氣洗滌塔，最終氣體排放濃度要滿足CCIQ的相關標準。此部分將有空調及排風系統的承包商負責。

2.3　　There shall be 10 air changes per hour of ventilation in wet laboratories and 8 air changes per hour of ventilation in dry laboratories. With approval, airflow may set back to 6 air changes per hour when space is unoccupied.
化學實驗室空氣換風量至少為10次每小時，儀器室至少為8次每小時。如經過同意，當實驗室無人時，可以將換氣量降為6次每小時。

2.4　　Hood exhausts may be manifolded together. Exhausting highly reactive, incompatible or highly toxic materials shall not be manifolded and exhausted directly to the outside. Special exhaust cleaning system shall be provided in dedicated exhaust system.
通風柜排氣管路可以連接在一起。產生高反應活性、性質不相容、強毒性氣體的通風柜管路不能連接在一起，并且直接排除室外。某些排氣管路需要有清洗裝置。（如高氯酸通風柜）

2.5　　Acid and solvent storage cabinets need to be vented. These cabinets shall be connected directly to an exterior exhaust duct above the fume hood trim or balancing damper.
酸柜和溶劑柜根據情況需要有通風裝置。可以直接連接到通風柜排氣系統中去。

3.　　FUME HOOD (通風柜)

Bench-type fume hood is the main type in CCIQ laboratory.
臺式通風柜是CCIQ實驗室主要的通風柜。

Fume hood face velocity shall be 100fpm (0.5m/s), actual exhaust volume shall be 900 m3/h to 1150 m3/h according to SEFA & AHRAE recommendations. Canopy hood shall have 600m3/h each outlet to ensure weak negative exhaust. The volume of other exhaust outlet for vented cabinet, vacuum oven etc. should comply with equipment requirement.
通風柜表面風速為0.5m/s，根據SEFA和AHRAE的要求，通風柜排氣量在900 m3/h 到 1150 m3/h之間。每個排氣罩排氣量在600m3/h。另外，在特殊存儲柜和儀器上方排氣罩的排氣量滿足設定的要求。每個排氣口保持負壓。
 

4. 　　EXHAUST FAN (排氣風機)

4.1　　Exhaust fan should be sized to provide enough suction and flow velocity at each of the exhaust point in the laboratory
　　排氣風機的大小要滿足足夠的風量和表面風速。
　　
4.2　　Each main exhaust pipe shall have one exhaust fan.
一個風機控制一個主要的排氣管道。

4.3　　Exhaust fans shall be a belt driven, centrifugal type
排氣風機為皮帶式，離心風機。

4.4　　Exhaust fans shall be installed on the roof of the building.
風機安裝在房頂。　
　
4.5　　Exhaust fans shall be UPVC or equivalent material with chemical resistant.
風機由UPVC或類似的材料建造。

5.　　 EXHAUST DUCT (排氣管道)

5.1　　 Exhaust ducts shall be made of PVC or equivalent
排氣管道由PVC或類似的材料建造。

5.2　　Mechanical volume control damper shall be available at each exhaust point to enable easy balancing.
每個排氣點上由機械控制閥門來保持氣壓平衡。

5.3　　These mechanical dampers shall be easily accessible for maintenance.
這種控制閥門易維護。

5.4　　Ducts shall be suitably welded or sealed for leakage.
管路有合適的焊接和密封，來保證不泄漏。

5.5　　Provision should be added to prevent possible leakage of water in to the duct system thus into the laboratory.
要保證水不會滲透到管路里，從而進入實驗室。

 
6.　　SCRUBBER SYSTEM (氣體凈化塔)

6.1　　This system is used for the chemical laboratory and its functions to remove harmful vapors from the exhausted air by means of water or specified reagent dilution.
化學實驗室排氣系統需要有空氣凈化塔，通過水和特殊試劑對排氣中有害氣體進行洗滌。

6.2　　Scrubber system often includes spray system, absorbing system and collection system. The exhaust gas is led to the inlet of the system and contacts with the down-steam so that the gas can be soluble or be capable of reacting chemically with the scrubbing liquid. At last, the liquid should be collected in collecting section.
凈化系統包括布水裝置、吸收系統和收集系統。排氣引入凈化塔下部，和上面噴灑的溶劑接觸，氣體溶解或與溶劑產生化學反應，最后溶劑被收集裝置收集。

6.3　　The degree of solubility depends on the type of gas, its concentration (more fraction or vapor pressure), the system pressure, the type of absorbing liquid, and the liquid temperature.
溶解程度和氣體種類、濃度、系統壓力、吸收液種類、溫度等多種條件有關。

6.4　　If liquid reaches equilibrium within the scrubbing media, it cannot absorb additional gas. To prevent equilibrium from occurring and drastically reducing the removal efficiency, fresh liquid is introduced and contaminated liquid is withdrawn from the system.
如果溶劑在吸附材料表面的達到平衡，溶劑就不能再吸附多余氣體。為了避免這一現象，新的溶劑要引入，污染的溶劑要排除。

6.5　　Since it is the liquid that is absorbing the gas, a means of extending the liquid surface must be provided. This is why an effective scrubbing media is needed. By providing a good scrubbing media over which the liquid is spread, a greater area of contact can be achieved and this area of gas-liquid contact is the area of the scrubbing media.
因為是溶劑吸附了氣體，所以氣液接觸面就要大。所以，吸附材料要好，氣－液接觸表面在吸附材料上有很大的延伸面。