How to Select Cooling Towers for High Ambient Conditions
- nexoradesign.net
- Mar 24
- 16 min read
Middle East / Tropical Climate Design Guide
Selecting a cooling tower for a mild climate is straightforward compared with selecting one for Doha, Dubai, Muscat, Jeddah, Colombo, Chennai, or any other location where outdoor wet-bulb temperature stays high for long periods and summer reliability is non-negotiable. In these climates, many projects fail not because the cooling tower was “undersized” in a simple sense, but because the design team treated cooling tower selection like a catalog exercise instead of a system-level engineering decision.
In hot and humid regions, the cooling tower is often the weakest thermal link in the chilled water plant. The chiller may be selected with strong full-load and part-load performance, pumps may be sized correctly, and controls may be sophisticated, yet the whole plant still underperforms if condenser water cannot be cooled to the temperature assumed in the chiller selection. Once that happens, compressor lift rises, chiller kW/TR deteriorates, available capacity drops, and the energy model becomes fiction. In extreme cases, the plant cannot hold design indoor conditions during the exact hours when the building needs peak performance.
That is why cooling tower selection in the Middle East and tropical climates must be approached with the mindset of a senior plant designer, not a product buyer. The correct question is not, “Which tower gives 35°C leaving water?” The correct question is, “What tower configuration, cell arrangement, redundancy philosophy, water treatment strategy, drift/noise footprint, and control sequence will reliably deliver required condenser water performance under the real climatic, hydraulic, fouling, and operational conditions of this project?”
A cooling tower is fundamentally selected based on hot water temperature, cold water temperature, water flow, and entering air wet-bulb temperature. Range is the temperature drop across the tower, and approach is the difference between tower cold-water temperature and ambient wet-bulb temperature. The colder the leaving water must be relative to wet bulb, the tighter the approach and the larger and more energy-intensive the tower generally becomes. Cooling tower performance is driven mainly by wet-bulb temperature, not dry-bulb temperature, and thermal ratings are commonly validated through CTI certification programs such as CTI STD-201.
This guide is written for MEP consultants, developers, and HVAC engineers who need a practical, consulting-level framework. It will go beyond definitions and show how to make decisions under real project pressure: high wet bulb, limited roof area, plume/drift concerns, poor makeup water quality, acoustic constraints, N+1 requirements, seasonal energy targets, and commercial pressure to reduce capex. (How to Select Cooling Towers for High Ambient Conditions)
1. Fundamentals of Cooling Tower Selection in High Ambient Climates
1.1 What the tower is really doing
A cooling tower rejects heat from the condenser water loop by evaporative cooling. A small portion of circulating water evaporates into the air stream, removing heat from the remaining water. The tower is therefore not just “a heat exchanger” in the ordinary dry-surface sense. Its thermal performance depends heavily on the entering air wet-bulb condition because wet bulb represents the practical lower limit to which the water can be cooled through evaporation.
For design engineers, this leads to one critical reality:
The chiller plant does not see ambient dry bulb directly. It sees condenser water temperature, and that temperature is constrained by ambient wet bulb.
In high ambient dry climates, dry bulb may be severe but wet bulb may still be manageable. In tropical and coastal climates, the real problem is often the elevated wet bulb. That is why projects in hot-humid regions can struggle even when the dry-bulb headline temperature does not look extreme.
1.2 Key terminology that must be understood correctly
Range
Range is the difference between hot water entering the tower and cold water leaving the tower.
Range = Thot − Tcold
Example:
Hot water in = 39°C
Cold water out = 32°C
Range = 7°C
Approach
Approach is the difference between cold water leaving the tower and entering ambient wet-bulb temperature.
Approach = Tcold − Twb
Example:
Cold water out = 32°C
Ambient wet bulb = 28°C
Approach = 4°C
Approach is usually the more difficult part of the selection. A small approach means the tower must cool water closer to wet bulb, which requires more fill area, more airflow, more fan power, or all three. Industry guidance consistently treats approach as a core indicator of tower thermal difficulty and effectiveness.
Tower effectiveness
A common expression is:
Effectiveness = Range / (Range + Approach)
This is useful for comparison, but in real design work it is not enough by itself. Two towers with similar “effectiveness” may differ significantly in footprint, fan energy, plume behavior, fouling resistance, and redundancy value.
1.3 Why high ambient climates are more demanding
In high ambient regions, cooling tower selection becomes harder for six reasons:
First, the design wet bulb is high, so the thermal driving force is reduced.
Second, peak load hours are long, not just short afternoon spikes.
Third, condenser water temperatures directly punish chiller efficiency. Even a modest rise in condensing temperature can materially increase compressor power.
Fourth, recirculation risk is higher on tight roof sites where hot saturated discharge air may re-enter the tower.
Fifth, water quality is often poor or treatment-intensive, particularly where TDS is high, makeup is expensive, or reclaimed water is used.
Sixth, the plant often needs high resilience, especially for hospitals, airports, district cooling interfaces, premium hospitality, and data-heavy facilities.
These factors mean that a tower selected exactly at nominal conditions with no margin may be technically “correct” on paper and still become a commercial problem in operation.
2. Strong Design Philosophy for Middle East and Tropical Projects
A weak selection approach says:
Load = X
Flow = Y
Wet bulb = Z
Vendor picks a tower
Done
A correct approach says:
Establish true peak condenser heat rejection, not just nominal chiller tonnage.
Confirm entering design wet bulb from appropriate climate data and project brief.
Decide acceptable leaving condenser water temperature under design and off-design conditions.
Decide redundancy philosophy: duty, N+1, N+2, or maintainability.
Evaluate tower type: open circuit, closed circuit, or hybrid.
Check water chemistry and cycles of concentration assumptions.
Review footprint, structural load, discharge clearance, recirculation risk, noise, plume, and access.
Assess fan energy and annual operating cost, not just first cost.
Verify certified thermal performance and realistic control turndown.
Design the basin, equalization, staging, and bypass arrangement so the tower can actually operate as intended.
This is what separates a consulting-grade design from a purchase-driven selection.
Read related topics
3. Step-by-Step Cooling Tower Selection Methodology
3.1 Step 1: Establish actual heat rejection (How to Select Cooling Towers for High Ambient Conditions)
Do not size the tower from chiller cooling capacity alone.
For water-cooled chillers, the cooling tower must reject:
Qrej = Qevap + Wcomp
Where:
Qrej = total condenser heat rejection
Qevap = evaporator cooling load
Wcomp = compressor power
A practical preliminary approximation is:
Qrej≈1.20 to 1.30×Qevap
For many comfort-cooling water-cooled chiller applications, engineers often use around 1.25 times evaporator load as a first-pass estimate, then refine using actual manufacturer data.
Example
Required evaporator load = 3,500 kW
Assume heat rejection factor = 1.25
Qrej = 1.25 × 3500 = 4375 kW
This 4,375 kW is the heat the tower must reject.
If you use only 3,500 kW for cooling tower selection, the tower will be materially undersized.
3.2 Step 2: Convert heat rejection to condenser water flow
Use:
Q = m˙cpΔT
For water:
cp≈4.186 kJ/kg\cdotpK
Density ≈1000 kg/m3
If design range is 5.5°C:
m˙=Q / (cpΔT)
m˙ = 4375 / (4.186×5.5) = 190 kg/s
Flow in L/s is approximately 190 L/s.
In m³/h:
190×3.6=684 m3/h
That becomes your design condenser water circulation rate.
3.3 Step 3: Select realistic design wet bulb
This step is often mishandled.
Do not select cooling towers from casual “summer weather” numbers or dry-bulb assumptions. Tower thermal selection is driven by coincident or specified entering air wet bulb. Manufacturer literature and engineering fundamentals consistently rate towers by water flow, hot water temperature, cold water temperature, and entering wet bulb.
For premium commercial projects, use one of the following, depending on project standard:
ASHRAE or equivalent climatic design data
Employer’s requirements
Local authority/project specification
Historical weather analysis with proper engineering judgement
District cooling utility requirements where applicable
For high-value projects, I generally do not recommend selecting strictly at historical average peak wet bulb. A more conservative design wet bulb may be justified where any loss of capacity is unacceptable.
Practical design note
If the tower is enclosed or surrounded by screening walls, or placed near taller structures, additional allowance may be required for local recirculation effects. Manufacturer engineering data notes that site conditions can justify increasing the effective design wet bulb or enlarging the tower selection.
3.4 Step 4: Decide required leaving condenser water temperature
This is where plant strategy matters.
A lower leaving condenser water temperature improves chiller efficiency, but requires more tower capacity and usually more capex. A higher leaving temperature reduces tower size but increases chiller power and may reduce available chiller capacity.
This is not merely a mechanical decision; it is an economic optimization.
Example design options at the same design wet bulb:
Option A: 31°C leaving condenser water
Option B: 32°C leaving condenser water
Option C: 33°C leaving condenser water
The 1–2°C difference may look small, but across thousands of annual full-load equivalent hours, the energy cost impact can be substantial.
3.5 Step 5: Calculate approach and test selection difficulty
Suppose design wet bulb is 28°C and target leaving condenser water is 32°C:
Approach=32−28=4∘C
A 4°C approach in high ambient conditions is already a serious selection.
If leaving water target is 31°C:
Approach=31−28=3∘C
That is significantly more difficult and usually means a much larger tower or more cells.
The closer the required cold water gets to wet bulb, the steeper the capital and fan energy penalty becomes.
3.6 Step 6: Decide number of cells and redundancy logic
This is one of the most important decisions and one of the most commercial.
For premium projects, I usually review at least three arrangements:
Minimum first-cost duty arrangement
N+1 arrangement
Maintainability-driven arrangement with favorable low-load staging
Example
Total required flow = 684 m³/h
Possible layouts:
2 cells × 342 m³/h
3 cells × 228 m³/h
4 cells × 171 m³/h
3 duty + 1 standby
More cells may increase first cost, basin complexity, and controls, but often improve:
staging flexibility
low-load efficiency
maintenance continuity
partial redundancy
approach control at varying wet bulb
For hospitals, mission-critical hospitality, or large mixed-use developments, a strict minimum-cell strategy often becomes expensive later.
3.7 Step 7: Confirm certified thermal selection
For commercial-grade procurement, specify certified thermal performance. CTI certification programs are widely used to verify that published ratings are supported by recognized performance procedures, rather than optimistic marketing assumptions.
A non-certified selection may still perform, but from a consulting and risk standpoint it weakens your position.
4. Detailed Technical Explanation: What Really Controls Tower Size in Hot Climates
4.1 Wet bulb versus dry bulb
Many non-specialists focus on dry bulb because it is the number everyone knows from weather reports. Cooling tower selection is different. Evaporative performance depends on wet bulb because the tower rejects heat mainly through evaporation. This is why coastal Gulf and tropical conditions are especially difficult: wet bulb stays high, so the tower’s theoretical cooling floor rises with it.
4.2 Why small approach becomes expensive fast
Going from a 6°C approach to a 5°C approach is not a simple linear change.
Going from 5°C to 4°C is harder.
Going from 4°C to 3°C is much harder.
That difficulty can manifest as:
larger fill pack
larger casing size
higher fan airflow
more fan horsepower
more cells
taller tower
higher drift eliminator resistance
stricter water distribution quality
This is why premium plants should study the whole-plant cost, not optimize the cooling tower in isolation.
4.3 Open circuit versus closed circuit towers
Open circuit cooling towers
These are standard condenser water towers where water is exposed directly to the air stream.
Advantages:
lower first cost
common for large HVAC plants
strong heat rejection economics
easy familiarity among contractors
Disadvantages:
condenser water exposed to atmosphere
greater fouling/corrosion concerns
stronger dependence on treatment discipline
open basin contamination risk
Closed circuit towers
These reject heat through coils while process water remains enclosed.
Advantages:
process loop protection
lower direct contamination risk
beneficial for some industrial or specialty systems
Disadvantages:
higher first cost
coil fouling risk on spray side
often larger and more energy-intensive for same duty
not always the best value for ordinary large condenser water plants
For mainstream water-cooled chillers in large buildings, open-circuit towers are usually the default unless water isolation, glycol, process cleanliness, or application-specific factors justify closed circuit.
4.4 Crossflow versus counterflow
Crossflow towers
Air moves horizontally through falling water.
Pros:
lower static pressure in many designs
easier hot-water basin access
often simpler maintenance access
lower pump head implications in some configurations
Cons:
larger plan area
potential exposure issues in dusty conditions
performance sensitivity depends on model design
Counterflow towers
Air moves vertically upward against falling water.
Pros:
often more compact footprint
good for constrained sites
frequently preferred where plan area is limited
Cons:
may have higher airside resistance depending on design
distribution system and maintenance preferences vary by manufacturer
There is no universal winner. In high-ambient urban sites, footprint, plume path, access, and recirculation geometry often matter more than textbook preferences.
5. Real Project Example with Numbers
Let us work through a realistic example.
5.1 Project brief
Project: premium mixed-use development in a Gulf coastal city
Chiller plant: 2 × 1,000 TR water-cooled chillers
Peak simultaneous load: 1,600 TR
Redundancy requirement: plant must maintain operation with one tower cell out of service
Site limitation: roof-mounted tower yard with acoustic screen walls
Target condenser water temperatures: 37°C entering chiller condenser, 32°C leaving tower
Design entering air wet bulb: 28°CWater side design range: 5°C
5.2 Convert load to kW
1600 TR×3.517=5627 kW
Evaporator load = 5,627 kW
Assume heat rejection factor = 1.25
Qrej = 5627×1.25 = 7034 kW
5.3 Flow calculation
m˙=7034 / (4.186×5) = 336 kg/s
Approximately:
336 L/s
1,210 m³/h
5.4 Approach
Approach=32−28=4∘C
A 4°C approach at this duty is a serious but achievable commercial selection.
5.5 Possible cell arrangements
Option 1: 3 cells total
Each cell duty at full load:
1210/3=403 m3/h per cell
If one cell fails, two cells remain:
2×403=806 m3/h
That is only 66.6% of required flow.
Unless the system is intentionally derated, this does not meet maintainability goals.
Option 2: 4 cells total
Each cell duty:
1210/4=302.5 m3/h
If one cell is unavailable, three cells remain:
907.5 m3/h
Still only 75% of full design flow. Depending on project brief, this may support reduced load but not full-load resilience.
Option 3: 5 cells total with 4 duty + 1 standby logic
If each operating cell is sized for:
1210/4=302.5 m3/h
Then at peak, 4 cells run and 1 remains standby.
If one cell is unavailable, standby becomes active and full design is maintained.
This is more expensive, but for premium resilience it is the correct answer.
5.6 Fan power and energy trade-off
Assume:
Option A tower selection at 32°C leaving water: total tower fan power = 60 kW
Option B tower selection at 31°C leaving water: total tower fan power = 85 kW
Difference = 25 kW additional tower fan power
Now assume the colder condenser water improves chiller plant efficiency by 0.045 kW/TR at 1,600 TR.
ΔPchiller=1600×0.045=72 kW
Net plant benefit:
72−25=47 kW
If annual equivalent operating hours at meaningful load = 3,500 h:
47×3500=164,500 kWh/year
At electricity cost of 0.12 USD/kWh:
164,500×0.12=19,740 USD/year
If the improved tower option costs an additional 80,000 USD, simple payback is:
80,000/19,740≈4.1 years
This is why cooling tower selection must be done against total plant economics, not tower cost alone.
6. Design Considerations and Engineering Judgement
6.1 Recirculation risk
This is a major issue in roof-mounted urban projects.
If discharge air re-enters the tower intake, effective entering wet bulb rises. That means the tower behaves as though the weather is worse than design. Manufacturers specifically warn that site layout, enclosures, and neighboring structures can justify higher effective design wet-bulb assumptions or larger selections.
Common causes:
decorative screens too close to louver faces
towers in pits or wells
inadequate spacing between cells
discharge air trapped by parapets
low discharge velocity
prevailing wind ignored
This is one of the biggest reasons installed towers underperform despite matching catalog data.
6.2 Water treatment and cycles of concentration
In high-ambient regions, evaporation loss is high, so makeup and blowdown strategy matter financially.
Approximate evaporation rate:
E=0.00085×1.8×C×Δ
or more commonly in practical HVAC estimates:
E≈0.001×Circulation Rate×ΔT
Using circulation flow =1210 m3/h, range =5∘C:
E≈0.001×1210×5=6.05 m3
That is a meaningful water consumption rate.
If cycles of concentration = 4:
Blowdown = E / (C−1) = 6.05 / 3 = 2.02 m3/h
Drift and overflow not included yet.
Where makeup water is expensive or chemically difficult, water cost can materially affect lifecycle economics.
6.3 Material selection
For Middle East and tropical climates, do not treat tower construction as an afterthought.
Review:
casing material
basin material
structural frame
fasteners
fill type
drift eliminator durability
UV resistance
corrosion class
splash bars or film fill suitability
If water quality is marginal or suspended solids are significant, the wrong fill can destroy long-term thermal stability.
6.4 Acoustic design
A quiet tower is not a free tower.
Noise control options include:
low-speed fans
larger towers at lower rpm
variable frequency drives
silencers/attenuators
acoustical barriers
better siting
But acoustic measures may increase footprint or airside pressure drop. Manufacturer engineering data notes that significant sound reduction can require larger tower size or fan speed reduction strategy.
The correct question is not “Can you make it quiet?”
It is “What is the thermal and financial penalty of the required noise target?”
7. Cost, Energy, and ROI Perspective
Cooling tower design decisions affect five cost layers:
7.1 First cost
Includes tower body, fan motors, VFDs, basin heaters if required, piping, supports, controls, and access platforms.
7.2 Structural and space cost
Larger towers mean:
bigger roof area
stronger supports
more crane complexity
possibly more plant deck area
7.3 Chiller energy cost
Warmer condenser water raises chiller power and may reduce capacity. Over the life of the plant, this is often the largest cost lever.
7.4 Tower fan and pump energy cost
Larger towers can reduce required fan speed at some conditions, but more cells and more static pressure may change the result. Always compare annualized energy, not just nameplate power.
7.5 Water and treatment cost
In high ambient climates, evaporation is not small. Water scarcity or high treatment burden can materially alter the economics.
Commercial rule
If the building has high occupancy, long operating hours, and premium indoor-condition expectations, spending more on tower capacity is often justified.
If the building has low annual run hours, mild part-load exposure, and lower reliability requirements, aggressive tower oversizing may not pay back.
8. Common Mistakes to Avoid
This section is critical because most cooling tower failures in design come from predictable errors.
8.1 Selecting from chiller tons instead of condenser heat rejection
This is the classic error. The tower rejects compressor heat too, not just evaporator load.
8.2 Using dry bulb instead of wet bulb
This immediately corrupts the selection basis.
8.3 Selecting an unrealistically tight approach without economic justification
Designers sometimes specify very cold condenser water because it “sounds efficient” without calculating lifecycle return.
8.4 Ignoring recirculation and site geometry
A perfect catalog selection can fail on a bad roof layout.
8.5 No redundancy philosophy
A premium project without a clear cell failure strategy is not premium engineering.
8.6 Poor basin and staging design
Uneven flow, dead zones, unstable basin levels, and weak cell isolation cause operational headaches.
8.7 Neglecting water chemistry
High ambient operation amplifies evaporation and scaling risk. A tower that works clean in theory may foul rapidly in practice.
8.8 Choosing solely by lowest capex
This is where developers lose money over time. A cheaper tower that raises chiller kWh all summer can be the most expensive option in the plant.
8.9 Ignoring off-design performance
Most plants do not run at one condition. You need stable staging, turndown, and control across varying loads and weather.
8.10 No requirement for certified thermal performance
That weakens technical assurance and procurement discipline.
9. Optimization Strategies
9.1 Use variable speed fans
VFD control is one of the most valuable tower features in high ambient climates because it allows:
condenser water temperature reset
better part-load efficiency
smoother staging
lower noise at reduced load
9.2 Optimize condenser water setpoint, not just minimize it blindly
Some plants benefit from lower condenser water whenever ambient permits. Others should use optimized reset logic to balance chiller and tower energy.
9.3 Use more cells where low-load efficiency matters
More cells can improve staging and reduce fan energy at part load, though not always. This must be tested against real plant control logic.
9.4 Protect against recirculation early in design
Spend time on layout before tender. This is much cheaper than solving thermal short-circuiting after construction.
9.5 Coordinate tower selection with chiller manufacturer data
Do not assume generic chiller response. Use actual condenser performance curves where possible.
9.6 Evaluate hybrid or adiabatic alternatives only where justified
In water-scarce projects, hybrid strategies may deserve study, but they must be compared honestly on capital, maintenance, and climate suitability.
10. Advanced Insights for Experienced Engineers
10.1 The best tower is not always the one with the lowest design leaving temperature
In some climates, the total annual energy optimum is not at the coldest possible condenser water because tower fan energy, extra cell count, and water use can offset part of the chiller gain.
10.2 Peak design is not the only design condition
A tower may meet one summer peak point but perform poorly during shoulder-season low-load operation if minimum flow, staging, and bypass are not handled correctly.
10.3 Maintainability is a real capacity parameter
A four-cell tower without service flexibility is not functionally equivalent to a five-cell tower with one standby position in a mission-critical plant.
10.4 Fill selection is strategic
Film fill may provide excellent thermal performance with cleaner water, but in dirtier conditions splash or fouling-resistant alternatives may deliver better long-term plant reality, even if catalog performance looks less attractive.
10.5 Specifying margin the wrong way can backfire
Instead of vaguely adding “10% extra tower capacity,” it is better to define:
certified thermal duty
design wet bulb
allowable leaving water temperature
recirculation/site adjustments
fouling/water quality basis
redundancy requirement
fan control sequence
Good engineering margin is structured, not random.
Read related topics
11. FAQ
1. Should cooling towers in Gulf climates be oversized?
Often yes, but only for defined reasons such as recirculation risk, resilience, low-noise operation, or lifecycle energy optimization. Blind oversizing is poor engineering.
2. What matters more for cooling tower selection: dry bulb or wet bulb?
Wet bulb. Cooling tower thermal performance is fundamentally rated against entering air wet-bulb temperature.
3. What is a good approach for high ambient HVAC projects?
There is no universal answer. Around 4–6°C may be commercially practical for many projects, while tighter approaches can be justified for energy-intensive premium plants.
4. Should I select the lowest possible condenser water temperature?
Not automatically. You should optimize total plant cost and efficiency, not one component.
5. Is CTI certification important?
Yes. It strengthens confidence that the published thermal ratings are backed by recognized certification procedures.
6. Are more tower cells always better?
No. They improve flexibility and redundancy, but add cost, controls complexity, and basin/piping considerations.
7. Can acoustic screens cause performance issues?
Yes. They can increase recirculation if badly configured.
8. How important is water treatment in tropical climates?
Extremely important. High evaporation and warm water accelerate scaling, corrosion, and biological risk.
9. Is open circuit still acceptable for premium commercial plants?
Yes, very commonly, provided treatment, materials, and maintenance are handled properly.
10. What is the most common selection mistake?
Using evaporator load instead of total condenser heat rejection.
11. Should towers be roof-mounted or ground-mounted?
Either can work. The right answer depends on structural cost, recirculation risk, access, acoustic context, and plume/discharge path.
12. How do I account for one cell out of service?
Do not just divide total load by number of cells. Define duty/standby philosophy clearly and size the active duty cells accordingly.
13. Are closed-circuit towers better in high ambient climates?
Not inherently. They may be better for water isolation or process reasons, but not always for mainstream HVAC economics.
14. Does a lower tower fan speed help?
Yes for noise and part-load efficiency, but only if the tower has enough thermal surface and control logic to maintain required leaving water temperature.
15. What should I emphasize in the specification?
Certified thermal performance, design wet bulb, leaving water temperature, cell redundancy, materials, drift limits, acoustic requirements, VFD operation, water quality basis, and site recirculation consideration.
13. Conclusion
Cooling tower selection for high ambient conditions is one of the most underestimated decisions in central plant design. In the Middle East and tropical climates, the tower is not a background accessory to the chiller plant. It is a primary determinant of summer stability, chiller efficiency, water consumption, and long-term operating cost.
A strong engineer does not ask only whether the tower can meet nominal duty. A strong engineer asks whether the tower can do so under real roof conditions, real fouling, real staging, real water chemistry, and real resilience expectations. That requires correct heat rejection calculations, proper wet-bulb-based selection, rational approach decisions, clear redundancy philosophy, and honest lifecycle economics.
For premium projects, the cheapest cooling tower is rarely the cheapest plant solution. A properly selected tower can reduce compressor power, protect available chiller capacity, improve resilience, and prevent the kind of performance shortfall that becomes painfully visible only after handover.
That is the real consulting perspective: select the cooling tower not as equipment, but as a strategic thermal asset in the plant.
12. Author’s Note
This guide is for guidance only. Final cooling tower selection must be based on project-specific load calculations, local climatic design data, manufacturer-certified performance, water chemistry, authority requirements, structural constraints, acoustic criteria, and the operational priorities of the owner.
Comments