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Air Conditioning System တစ္ခုကိုေရြးခ်ယ္ၿခင္း

Air Conditioning အင္ဂ်င္နီယာတစ္ေယာက္သည္ အမ်ိဳးမ်ိဳးေသာ system မ်ားကိုသိနားလည္ၿပီး မိမိဒီဇုိင္းၿပဳလုပ္မည့္ Project ၏ လုိအပ္ခ်က္၊လုပ္ေဆာင္ခ်က္ႏွင့္ရည္မွန္းခ်က္မ်ားနွင့္သင္ေလွ်ာ္ေသာ ဒီဇုိင္းတစ္မ်ိဳးသုိ့ ၂မ်ိဳးကို ေရြးခ်ယ္ကာ recommendation ေပးရန္တာဝန္ရွိသည္။ ထုိ system သည္ ဒီဇုိင္းလုပ္သည့္အတိုင္း Perform လုပ္ရန္ လည္းတာဝန္ရွိသည္။

ဒီဇုိင္းအင္ဂ်င္နီယာႏွင့္ပုိင္ရွင္တုိ့ ႏွစ္ဦးႏွစ္ဘက္ အေရးၾကီးသည့္ ဒီဇုိင္းလုိအပ္ခ်က္မ်ားကိုဦးစားေပးေရြးခ်ယ္ကာလက္တြဲလုပ္ကိုင္ရမည္ၿဖစ္သည္။ထုိ့အၿပင္ေဆာက္လုပ္ေရးလုပ္ငန္းခြင္တြင္လည္း ဒီဇုိင္းအင္ဂ်င္နီယာႏွင့္ construction manager တုိ့ ညိွနုိင္းတုိင္ပင္ၿပီး ပိုမိုေကာင္းမြန္ၿပီးတန္ဘုိးတက္လာမည္နည္းလမ္းမ်ား ကုန္က်စရိတ္သက္သာမည့္နည္းလမ္းမ်ား(value-engineered options)ကို ရွာေဖြရမည္ၿဖစ္သည္။

ေနထုိင္အသံုးၿပဳသူမ်ားအတြက္ ေအာက္ပါလုိအပ္ခ်က္မ်ားကို system ၏ဒီဇုိင္းတြင္ထည့္သြင္းစဥ္းစာရမည္ၿဖစ္သည္။
• Temperature ( အပူခ်ိန္စုိထုိင္းဆ)
• Humidity (စုိထုိင္းဆ)
• Air motion (ေလသြားႏွဳန္းႏွင့္ပက္သက္သည့္အရာမ်ား )
• Air purity or quality (ေလ၏ သန့္ရွင္းမွဳ )

• Air changes per hour(တစ္နာရီအတြင္းေလလဲလွယ္နွဳန္း)
• Air and/or water velocity requirements (Duct အတြင္း Pipe အတြင္းေလႏွင့္ေရသြားႏွဳန္း )
• Local climate ( တည္ေဆာက္မည့္ေနရာ၏ ရာသီဥတု)
• Space pressure requirements (အခန္းမ်ား ၏ ဖိအားလိုအပ္ခ်က္)
• Capacity requirements, from a load calculation analysis (Capacity လိုအပ္ခ်က္ႏွင့္ load calculation analysis)
• Redundancy ( အတိမ္းအေဆာင္ခံနုိင္မွဳ။ လုိအပ္သလုိေၿပာင္းလဲကာအသံုးၿပဳနုိင္မွဳ)
• Spatial requirements
• Security concerns (လုံၿခံဳေရး လိုအပ္ခ်က္္မ်ား ေပးနုိင္မွဳ)
• First cost ( ေဆာက္လုပ္ရန္အတြက္ ကုန္က်စရိတ္)
• Operating cost, including energy and power costs ( ေမာင္းႏွင္ရန္ Operatလုပ္ရန္ကုန္က်စရိတ္- ဓါတ္အားခ။ အလုပ္သမားခမ်ားပါဝင္သည္။)
• Maintenance cost ( ထိန္းသိမ္းၿပဳၿပင္ရန္ ကုန္က်စရိတ္)
• Reliability ( system ေပၚစိတ္ခ်နုိင္မွဳေကာင္းမေကာင္း)
• Flexibility ( လုိအပ္သလုိၿပဳၿပင္ေၿပာင္းလဲနုိင္စြမ္းရွိမရွိ)
• Life-cycle analysis (တပ္ဆင္ၿပီးစေမာင္းသည့္ေနမွ ဖ်က္သည့္ေနအထိ system အတြက္ကုန္က်စရိတ္စုစုေပါင္း)
• Sustainability of design (ဒီဇုိင္း၏တည္ၿမဲနုိင္စြမ္း)
• Acoustics and vibration ( အသံဆူညံမွဳနွင့္ တုန္ခါမွဳမ်ားကိုထိန္းခ်ဳပ္နုိင္စြမ္း)
• Mold and mildew prevention (စုိထုိင္းဆေၾကာင့္ အခန္းအတြင္းမွဳိမ်ားေပါက္ပႊားမွဳကိုကာကြယ္နုိင္စြမ္း)
အထက္ပါအခ်က္မ်ားသည္ တစ္ခုႏွင့္တစ္ခု အၿပန္အလွန္ဆက္ႏြယ္ အက်ိဳးၿပဳ (interrelated)ေနသည္။

Air Conditioning System မ်ားတြင္ Decentralized Cooling and Heating System ႏွင့္ Central Cooling and Heating System ဟု၍အဓိကအားၿဖင့္ႏွစ္မ်ဳိးရွိသည္။

Decentralized Cooling and Heating System သည္ အငယ္စားႏွင့္အလတ္စားအေဆာက္အဦးမ်ား။ လုပ္ငန္းမ်ား ႏွင့္ အသံုးၿပဳမွဳမ်ားအတြက္သင့္ေလ်ာ္သည္။

 

Decentralized Cooling and Heating System ၏ အားသာခ်က္မ်ား (Advantages)
• Heating and cooling can be provided at all times, independent of the mode of operation of other building spaces.
• Manufacturer-matched components have certified ratings and performance data.
• Assembly by a manufacturer helps ensure better quality control and reliability.
• Manufacturer instructions and multiple-unit arrangements simplify installation through repetition of tasks.
• Only one zone of temperature control is affected if equipment malfunctions.
• The system is readily available.
• One manufacturer is responsible for the final equipment package.
• For improved energy control, equipment serving vacant spaces can be turned off locally or from a central point, without affecting occupied spaces.
• System operation is simple. Trained operators are not usually required.
• Less mechanical and electrical room space is required than with central systems.
• Initial cost is usually low.
• Equipment can be installed to condition one space at a time as a building is completed, remodeled, or as individual areas are occupied, with favorable initial investment.

• Energy can be metered directly to each tenant.
• Air- or water-side economizers may be applicable, depending on type of decentralized system used.

Disadvantages
• Performance options may be limited because airflow, cooling coil size, and condenser size are fixed.
• Larger total building installed cooling capacity is usually required because diversity factors used for moving cooling needs do not apply to dedicated packages.
• Temperature and humidity control may be less stable, especially with mechanical cooling at very low loads.
• Standard commercial units are not generally suited for large percentages of outside air or for close humidity control. Custom or special-purpose equipment, such as packaged units for computer rooms, or large custom units, may be required.
• Energy use is usually greater than for central systems if efficiency of the unitary equipment is less than that of the combined central system components.
• Low-cost cooling by outside air economizers is not always available or practical.
• Air distribution control may be limited.
• Operating sound levels can be high, and noise-producing machinery is often closer to building occupants than with central systems.
• Ventilation capabilities are fixed by equipment design.
• Equipment’s effect on building appearance can be unappealing.
• Air filtration options may be limited.
• Discharge temperature varies because of on/off or step control.
• Condensate drain is required with each air-conditioning unit.
• Maintenance may be difficult or costly because of multiple pieces of equipment and their location.

 

Central Cooling and Heating System

The following facility types are good candidates for central cooling and/or heating systems:
• Campus environments with distribution to several buildings. (အေဆာက္အဦးမ်ားစြာရွိေသာ တကၠသိုလ္။ေကာလိပ္ကဲ့သို့ Campus မ်ား)
• High-rise facilities ( အထပ္ေပါင္းမ်ားစြာရွိသည့္မုိးထိတုိက္မ်ား)
• Large office buildings (အလြန္ၾကီးမားေသာအေဆာက္အဦးမ်ား)
• Large public assembly facilities, entertainment complexes, stadiums, arenas, and convention and exhibition centers- (ရုပ္ရွင္ရုံမ်ား၊ကြန္ဗန္းရွင္းစင္တာမ်ား၊ အားကစားရုံမ်ား ႏွင့္ ၿပခန္းမ်ား)
• Urban centers (e.g., city centers/districts)
• Shopping malls (ေရွာ့ပင္းစင္တားမ်ား။ ေရွာ့ပင္းေမာမ်ား)
• Large condominiums, hotels, and apartment complexes (ဟုိတယ္မ်ား။ အပါမန့္မ်ား)
• Educational facilities ( ပညာေရဆုိင္ရာအေဆာက္အဦးမ်ား)
• Hospitals and other health care facilities ( ေဆးရုံမ်ား ႏွင့္ က်န္းမာေရးဆုိင္ရာ အေဆာက္အဦးမ်ား)
• Industrial facilities (e.g., pharmaceutical, manufacturing)(ေဆးထုပ္လုပ္သည့္စက္ရုံမ်ား။ စက္ရုံမ်ား)
• Large museums and similar institutions ( ၿပတုိက္ၾကီးမ်ား)
• Locations where waste heat is readily available (result of power generation or industrial processes) (စြန့္ပစ္သည္ အပူမ်ားစြာရနုိင္ေသာေနရာမ်ား)

Advantages
• Primary cooling and heating can be provided at all times, independent of the operation mode of equipment and systems outside the central plant.
• Using larger but fewer pieces of equipment generally reduces the facility’s overall operation and maintenance cost. It also allows wider operating ranges and more flexible operating sequences.
• A centralized location minimizes restrictions on servicing accessibility.
• Energy-efficient design strategies, energy recovery, thermal storage, and energy management can be simpler and more costeffective to implement.
• Multiple energy sources can be applied to the central plant, providing flexibility and leverage when purchasing fuel.
• Standardizing equipment can be beneficial for redundancy and stocking replacement parts. However, strategically selecting different-sized equipment for a central plant can provide better part-load capability and efficiency.
• Standby capabilities (for firm capacity/redundancy) and back-up fuel sources can easily be added to equipment and plant when
planned in advance.

• Equipment operation can be staged to match load profile and taken offline for maintenance.
• District cooling and heating can be provided.
• A central plant and its distribution can be economically expanded to accommodate future growth (e.g., adding new buildings to the service group).
• Load diversity can substantially reduce the total equipment capacity requirement.
• Submetering secondary distribution can allow individual billing of cooling and heating users outside the central plant.
• Major vibration and noise-producing equipment can be grouped away from occupied spaces, making acoustic and vibration controls simpler. Acoustical treatment can be applied in a single location instead of many separate locations.
• Issues such as cooling tower plume and plant

 

Disadvantages
• Equipment may not be readily available, resulting in long leadtime for production and delivery.
• Equipment may be more complicated than decentralized equipment, and thus require a more knowledgeable equipment operator.
• A central location within or adjacent to the building is needed.
• Additional equipment room height may be needed.
• Depending on the fuel source, large underground or surface storage tanks may be required on site. If coal is used, space for storage bunker(s) will be needed.
• Access may be needed for large deliveries of fuel (oil or coal).
• Heating plants require a chimney and possibly emission permits, monitoring, and treatments.
• Multiple equipment manufacturers are required when combining primary and ancillary equipment.
• System control logic may be complex.
• First costs can be higher.
• Special permitting may be required.
• Safety requirements are increased.
• A large pipe distribution system may be necessary (which may actually be an advantage for some applications).

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Air Conditioning Systems ႏွင့္သက္ဆုိင္ေသာ ACMV Lecture မ်ား (1 Lectures)
1 Air Conditioning Systems Air Conditioning System တစ္ခုကိုေရြးခ်ယ္ၿခင္း Read
   

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