Broiler House Wind Speed and Airflow Measurement

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-14

Key Takeaways

• Air velocity, measured in feet per minute (fpm) or meters per second (m/s), is critical for broiler health and growth, with target speeds varying by bird age, outside temperature, and house width, ranging from below 50 fpm for day-old chicks to 400-700+ fpm for market-age birds in hot weather.
• A handheld rotating vane anemometer is the recommended practical tool for growers, requiring measurements at bird level across a grid pattern to identify dead spots and hot zones, with readings needing to be rechecked weekly and after any equipment changes.
• Uniform airflow is paramount; significant variations (over 30%) in air speed across the house can lead to uneven growth and reduced profitability, with acceptable variation typically within +/- 15% across width/length and 20-30% from pad end to fan end.
• Static pressure, measured in inches of water column, indicates resistance to airflow; high static pressure (above 0.15 inches) suggests restricted inlets or dirty pads, while low static pressure can signal unintended air leaks, both of which negatively impact wind speed and airflow.
• Bird behavior, such as panting, huddling, or uneven distribution, and litter condition (wet patches) serve as crucial real-time indicators of inadequate or uneven airflow, prompting investigation into fan performance, inlet openings, and obstructions.
• Recordkeeping of airflow measurements, including date, time, bird age, environmental conditions, static pressure, and ventilation mode, is essential for identifying trends, evaluating equipment performance, and making informed management decisions to optimize bird welfare and production efficiency.

Getting airflow right in a broiler house is one of the most important jobs you have as a poultry farmer. Birds grow faster, stay healthier, and convert feed more efficiently when the air around them moves at the right speed. This guide explains how to measure wind speed and airflow in a broiler house, what the numbers mean, and how to use that information to make better decisions about ventilation. It is written for broiler growers, farm managers, and poultry technicians who want a practical, hands-on approach to airflow management.

At a Glance

• Air velocity is measured in feet per minute (fpm) or meters per second (m/s). Most US broiler growers work in fpm.
• Target wind speed depends on bird age, outside temperature, and house width. Day-old chicks need very low air movement. Market-age birds in hot weather may need 400 to 700 fpm or higher.
• A handheld rotating vane anemometer is the most practical tool for most growers. A swinging vane anemometer is a good backup. Hot wire anemometers measure low speeds accurately but cost more.
• Measure at bird level, not at the fan or in the middle of the house. The air that matters is the air the birds feel.
• Take readings across a grid pattern in the house. Walk the full length and width so you find dead spots and hot zones.
• Air speed changes as birds grow. Recheck your measurements at least weekly and after any equipment change.
• Static pressure, fan performance, inlet openings, and pad condition all affect wind speed. If air speed is low, check these systems before assuming the fans are failing.
• Record your readings in a logbook or spreadsheet. Trends matter more than any single measurement.
• Call a veterinarian or extension agent if you see signs of respiratory distress, poor litter condition, or uneven bird growth that you cannot explain with your airflow data.

Why Airflow Matters in a Broiler House

Broilers are heavy birds with high metabolic rates. They produce a lot of heat and moisture. A 5 pound bird generates roughly 10 to 15 British thermal units of heat per hour. Multiply that by 30,000 birds and you have a serious heat load. Air movement removes that heat by convection and by helping moisture evaporate from litter and from the birds' respiratory tract.

When air moves across a bird, it pulls heat away from the body surface. This is called wind chill effect. The faster the air moves, the more cooling the bird feels. At 500 fpm, a market-age broiler in a 90 degree F house experiences an effective temperature that is several degrees cooler than the actual air temperature. This is why wind speed is so important during hot weather.

Airflow also keeps litter dry. Wet litter leads to ammonia, footpad lesions, and breast blisters. Good air movement at floor level carries moisture away before it soaks into the bedding. This is especially important in the winter when ventilation rates are lower to conserve heat.

Uniform airflow matters as much as total airflow. If one end of the house has dead air and the other end has a strong breeze, birds grow unevenly. The birds in the hot dead zone eat less and gain less. You end up with a house full of birds at different weights, which complicates processing and reduces your bottom line.

Understanding Wind Speed and Airflow Terminology

Before you start measuring, you need to understand the basic terms.

Air velocity is the speed of air movement, measured in feet per minute or meters per second. One meter per second equals 196.85 feet per minute. Most tunnel-ventilated broiler houses in the United States run at 300 to 700 fpm during hot weather.

Airflow is the volume of air moving through the house, measured in cubic feet per minute (cfm). Airflow equals air velocity multiplied by the cross-sectional area of the house. A house that is 40 feet wide and 8 feet tall at the sidewall has a cross-sectional area of roughly 320 square feet. At 500 fpm, the airflow is about 160,000 cfm.

Static pressure is the resistance to airflow, measured in inches of water column. It tells you how hard the fans are working against the house. Normal static pressure in a tunnel house runs 0.05 to 0.15 inches. High static pressure means restricted inlets or dirty pads. Low static pressure can mean air is leaking in where you do not want it.

Air exchange rate is how many times the total house volume is replaced per minute. In winter, you might exchange air every 8 to 10 minutes. In summer tunnel mode, you exchange the entire house volume in under a minute.

Bird effective temperature is what the bird actually feels. It combines air temperature, humidity, and wind speed. At 90 degrees F and 50 percent humidity, a 500 fpm breeze feels like about 80 degrees to a market-age broiler. This is why wind speed is so powerful.

The Tools for Measuring Wind Speed

You have several options for measuring air velocity in a broiler house. Each has strengths and weaknesses.

Rotating Vane Anemometer

This is the most practical tool for most broiler growers. It has a small fan or propeller on the end of a wand. The airflow spins the vane, and the instrument converts the rotation speed into an air velocity reading.

Rotating vane anemometers are durable, easy to use, and reasonably accurate in the 100 to 5,000 fpm range. They respond quickly, so you can take many readings in a short time. Most models have a digital display that shows current, average, and maximum readings.

Look for a model with a telescoping wand so you can reach down to bird level without bending over. A wand length of 3 to 4 feet is adequate for most houses. Some models have a remote sensor on a cable so you can take readings while standing in the walkway.

Rotating vane anemometers cost between $100 and $400. This is a reasonable investment for any commercial broiler operation.

Swinging Vane Anemometer

This is the classic mechanical anemometer. It has a set of vanes that deflect as air passes over them. The deflection moves a needle on a dial. It requires no battery and is very reliable.

Swinging vane anemometers work best in the 200 to 3,000 fpm range. Below 200 fpm, the needle does not move enough for a confident reading. They are slower to respond than digital units, so you need to hold them steady for 15 to 30 seconds per reading.

These are good backup tools. They are less expensive than digital units and cannot run out of battery. But they are more fragile and harder to read in dim light. Keep one in the farm office for emergency use.

Hot Wire Anemometer

A hot wire anemometer uses a heated wire or thermistor. Air passing over the wire cools it, and the instrument correlates the cooling effect with air velocity.

Hot wire anemometers are excellent at low speeds. They can measure down to 10 or 20 fpm with good accuracy. This makes them useful for minimum ventilation checks in winter.

The downside is cost and fragility. Good hot wire units cost $500 or more. The sensor is delicate and can break if dropped. They also drift over time and need regular calibration. Most broiler growers do not need this level of precision.

Pressure Based Measurements

Static pressure gauges do not measure wind speed directly. But they tell you whether the house is set up to produce the airflow you want. If static pressure is too high, air speed will drop because the fans cannot pull enough air through restricted openings.

A simple manometer or digital static pressure gauge is standard equipment on most broiler farms. Use it alongside your anemometer to diagnose airflow problems.

Calibration and Maintenance

Whatever tool you choose, keep it clean and calibrated. A dusty vane reads low. A bent vane reads wrong. Check the manufacturer instructions for cleaning and calibration schedules.

Most digital anemometers have a calibration offset you can adjust. Compare your unit against a known reference at least once a year. Many extension offices can help with this. If you drop the unit, recheck it immediately. A hard drop can bend the vane or knock the sensor out of alignment.

Preparing the House for Measurement

You cannot get useful airflow data from a house that is not in normal operating condition. Before you take readings, make sure the house is set up the way it runs in production.

First, check that all fans are clean and running. Dirty fan blades and shutters reduce airflow by 20 to 30 percent. A fan that is struggling to turn will not move the air it should. Clean the blades, shutters, and safety guards before measuring.

Second, check the evaporative cooling pads. Dirty or clogged pads restrict airflow. Water buildup in the pad system can also block air. Pads should be clean and dry when you measure air speed. If you measure with wet pads, you get a different reading than with dry pads. Be consistent about pad condition when you collect data.

Third, check the inlets. In tunnel mode, the air comes in through the evaporative cooling pads at one end and exits through fans at the other end. Sidewall inlets should be closed. If they are open, air will short-circuit through them and reduce the wind speed at bird level.

Fourth, make sure the house is at the correct static pressure. Adjust the inlet openings or fan capacity to match your target static pressure before you measure. A house at 0.05 inches of static pressure will have different air speeds than the same house at 0.15 inches.

Fifth, consider bird age and density. Air speed at bird level is affected by the birds themselves. Large birds create more obstruction and slow the air near the floor. If you are measuring a house with market-age birds, expect lower readings at floor level than in an empty house. This is normal. Measure with birds present because that is the condition that matters.

Finally, pick a day with stable weather. Wind outside the house can affect pressure inside the house, especially if the house is not tightly sealed. A calm day gives you the most repeatable readings. If you must measure on a windy day, note the wind conditions in your records.

Step by Step: How to Measure Airflow in a Broiler House

Follow this procedure to get reliable, repeatable wind speed data.

Step 1: Set the Ventilation Mode

Decide what you are measuring. Tunnel mode, minimum ventilation, and transitional ventilation have different airflow patterns. You cannot compare readings across modes. Set the controller to the mode you want to evaluate and let the house stabilize for 15 to 20 minutes before measuring.

For summer heat stress evaluation, measure in full tunnel mode with all tunnel fans running. For winter minimum ventilation checks, measure with only the minimum ventilation fans running. The procedure is the same, but the targets are different.

Step 2: Mark Your Measurement Points

Draw a simple grid on paper. Divide the house length into 5 to 10 equal sections. Divide the width into 3 to 5 equal lanes. A typical 500 foot house with 5 length sections and 3 width lanes gives you 15 measurement points. A 600 foot house with 10 length sections and 5 lanes gives you 50 points.

More points give you a better picture but take more time. Start with a coarse grid and add points in areas that look problematic.

Mark your points with chalk on the floor or with flags on the feeder lines. This helps you find the same spots on repeat visits.

Step 3: Measure at Bird Level

The air the birds feel is what matters. Hold the anemometer at bird height. For day-old chicks, that is just above the litter. For market-age birds, that is 6 to 12 inches above the floor, depending on bird size.

Do not hold the anemometer at your waist or chest height. The air speed at 5 feet above the floor can be 100 to 200 fpm higher than at bird level. Measuring at the wrong height gives you a false sense of security.

Step 4: Take Readings Across the Grid

Walk the grid and take a reading at each point. Hold the anemometer steady for 10 to 15 seconds at each spot. Let the reading stabilize before you record it.

Face the anemometer into the airflow. In tunnel mode, the air moves from the pad end to the fan end. Point the sensor directly into that flow. If you hold it at an angle, you get a low reading.

Record the average reading at each point. Most digital anemometers have an averaging function. Use it. A single instantaneous reading can be misleading because air speed fluctuates.

Step 5: Measure at Multiple Heights

At a few key points, take readings at several heights. Measure at 6 inches, 12 inches, 24 inches, and 48 inches above the floor. This tells you how the air speed profile changes with height.

In a well-designed tunnel house, air speed is fairly uniform from 6 inches to 48 inches. If you see a big drop at floor level, you may have an inlet or fan distribution problem.

Step 6: Map the Results

Write your readings on your grid map. Circle any point that is 20 percent or more below the house average. These are your problem areas.

Look for patterns. Is one side of the house consistently slower than the other? Is the air speed dropping as you move down the house? Are there dead spots near the sidewalls or around equipment?

Step 7: Repeat at Different Times

Airflow changes with outside temperature, humidity, and wind. Take readings in the morning, afternoon, and night. Take readings on hot days and cool days. This gives you a full picture of how the house performs across conditions.

For summer heat stress evaluation, measure on the hottest afternoon you can. That is when the birds need the most wind speed. If the house delivers adequate airflow on a 95 degree day, it will be fine on milder days.

What the Numbers Mean: Interpreting Air Velocity Readings

Air velocity targets depend on bird age, house design, and outside conditions. There is no single number that works for every house.

Minimum Ventilation Air Speeds

In minimum ventilation mode, the goal is air quality, not wind chill. You want to remove moisture and ammonia while conserving heat. Air speeds are low, typically 50 to 150 fpm at bird level.

The key measurement in minimum ventilation is not wind speed. It is air distribution. You want fresh air to reach the center of the house and mix with the warm air near the ceiling before it falls to floor level. If you measure high air speeds near the sidewalls but low speeds in the center, the air is falling too fast and chilling the birds near the walls.

For day-old chicks, air speed at bird level should be below 50 fpm. Chicks cannot regulate their body temperature well in the first week. A draft that feels gentle to you can chill a chick severely.

Transitional Ventilation Air Speeds

Transitional ventilation uses a combination of sidewall inlets and tunnel fans. Air speeds are moderate, typically 150 to 300 fpm. The goal is to remove heat without creating strong drafts.

Transitional mode is common in spring and fall when outside temperatures are moderate. The target wind speed depends on bird age. Young birds need less air movement than older birds.

Tunnel Ventilation Air Speeds

In full tunnel mode, the goal is maximum wind chill. Target air speeds for market-age birds are 400 to 700 fpm. Some modern houses with high bird densities run 800 fpm or more.

The table below shows general tunnel air speed targets by bird age and outside temperature. These are starting points. Adjust based on bird behavior and performance.

These targets assume 50 percent relative humidity. At higher humidity, you need more air speed to achieve the same cooling effect.

Evaluating Uniformity

The uniformity of air speed across the house is as important as the average. A house with an average of 500 fpm but a range of 200 to 800 fpm has serious problems. The birds in the 200 fpm zone are heat stressed while the birds in the 800 fpm zone are over-cooled.

A good tunnel house has air speed variation of plus or minus 15 percent across the width and length. If you see variation of 30 percent or more, investigate the cause.

Air speed typically drops as you move away from the fans. The highest air speed is usually near the fan bank. The lowest is near the evaporative cooling pads. A drop of 20 to 30 percent from fan end to pad end is common and acceptable. A drop of 50 percent or more indicates a problem.

Bird Behavior as a Cross Check

Your birds will tell you if the airflow is right. Learn to read their behavior.

Panting is normal in broilers at moderate temperatures. But excessive panting with wings spread and birds crowded near the pads or fans means they are too hot. If birds are huddled together or avoiding certain areas, they may be too cold.

Birds that are comfortable spread evenly across the house. They eat, drink, and rest in all zones. If you see birds packed into one area and avoiding another, check the air speed in the empty zone. It is probably too high or too low.

Litter condition is another indicator. Dry, crumbly litter across the whole house means airflow is adequate everywhere. Wet litter in patches means those areas have poor air movement.

Common Mistakes in Measuring Airflow

Even experienced growers make errors when measuring wind speed. Here are the most common mistakes and how to avoid them.

Measuring at the Wrong Height

This is the most common error. Holding the anemometer at chest height gives you air speeds that are much higher than what the birds feel. The air near the floor is slowed by friction with the litter and by the birds themselves.

Always measure at bird level. For chicks, that is within 2 inches of the litter. For market birds, that is 6 to 12 inches above the floor.

Measuring in the Wrong Location

Air speed varies across the house. Measuring in one spot gives you no useful information about the whole house. You need a grid of measurements.

Also avoid measuring directly in front of a fan or directly behind a support post. These spots have abnormal airflow. You want the general air movement in the open space where the birds live.

Holding the Anemometer at an Angle

The vane must face directly into the airflow. If you hold it at a 30 degree angle, you get a reading that is 13 percent low. At 45 degrees, the error is 29 percent.

Watch the instrument display while you adjust the angle. The highest reading is the correct one. That is the angle where the vane is perpendicular to the airflow.

Taking Instantaneous Readings

Air speed fluctuates constantly. A single reading can be 50 fpm higher or lower than the average. Always use the averaging function on your anemometer. Hold the unit in place for at least 10 seconds and record the average.

Measuring with Dirty Fans or Pads

Dirty equipment reduces airflow. If you measure with dirty fans, you get low readings that do not reflect the house potential. Clean everything before you measure. Then you know the readings reflect the house design, not the maintenance backlog.

Ignoring Static Pressure

Static pressure affects air speed. If the static pressure is too high, the fans cannot move enough air. If it is too low, air may be entering through unintended openings. Always check static pressure when you measure wind speed.

Comparing Different Modes

Air speed in minimum ventilation is not comparable to air speed in tunnel mode. They are different systems with different goals. Always record the ventilation mode with your readings.

Not Recording Data

Memory is unreliable. Write down your readings. Record the date, time, bird age, outside temperature, static pressure, fan settings, and ventilation mode. This data becomes your baseline for future comparisons.

Troubleshooting Low Air Speed

If your measurements show low air speed, work through this checklist to find the cause.

Check Fan Performance

Fans lose capacity over time. Belts stretch, blades accumulate dust, and motors wear. A fan that is 20 percent below rated capacity is common on farms that do not maintain their fans.

Measure fan performance by comparing the air speed at the fan outlet to the manufacturer rating. Most tunnel fans are rated at 0.05 to 0.10 inches of static pressure. If your fan is moving less than 80 percent of its rated capacity, it needs maintenance.

Check belt tension, blade condition, and shutter operation. Clean the blades and safety guards. Replace worn belts. A well-maintained fan can regain 10 to 20 percent of its lost capacity.

Check Static Pressure

High static pressure means the fans are working against excessive resistance. Common causes include:

• Dirty or clogged evaporative cooling pads
• Inlets that are too small or too few
• Obstructed air paths inside the house
• Closed or partially closed shutters

Low static pressure means air is leaking into the house through unintended openings. This reduces the effectiveness of the tunnel system because air enters through gaps instead of through the pads.

The correct static pressure depends on your house design. Check the house plans or ask your integrator for the target range. In general, tunnel houses run 0.05 to 0.15 inches of static pressure.

Check the Evaporative Cooling Pads

Dirty pads block airflow. A pad that is clogged with dust, algae, or mineral deposits can reduce airflow by 30 to 50 percent.

Inspect the pads visually. Hold your hand on the inside surface while the fans are running. You should feel a strong, even airflow across the entire pad. If some areas feel weak, the pad is clogged in those spots.

Clean the pads according to the manufacturer instructions. Some pads can be washed with a low pressure hose. Others need chemical cleaning. Replace pads that are beyond cleaning.

Check Inlet Openings

The total inlet opening must match the fan capacity. If the inlets are too small, the fans cannot pull enough air. This creates high static pressure and low air speed.

Measure the total inlet area and compare it to the fan capacity. A general rule is 1 square foot of inlet area per 300 to 500 cfm of fan capacity. Your integrator or house designer can give you the specific ratio for your house.

In tunnel mode, the primary inlet is the evaporative cooling pad area. Sidewall inlets should be closed. If they are open, air will enter through them instead of through the pads. This creates dead spots near the sidewalls and reduces the tunnel effect.

Check for Obstructions

Anything that blocks the air path reduces wind speed at bird level. Common obstructions include:

• Feed lines and water lines that sag too low
• Hanging brooders that are not raised
• Curtains or insulation that has fallen
• Equipment stored in the house
• Tall weeds or grass around the fan outlets

Raise equipment as high as possible during tunnel ventilation. A feed line that hangs 3 feet above the floor creates a significant obstruction. Raising it to 5 or 6 feet reduces the blockage.

Check the Fan Bank

The fans at the end of the house pull air through the tunnel. If some fans are not running, or if they are running at reduced speed, air speed drops.

Check that all tunnel fans are operating. Look at the shutters to confirm they are fully open. Listen for unusual noises that might indicate a failing motor or bearing.

Check for Air Leaks

Air leaks reduce the effectiveness of the tunnel system. If air enters through cracks and gaps, it does not flow in a smooth tunnel from pad to fan.

Inspect the house for leaks. Common leak points include:

• Gaps around doors and curtains
• Holes in the ceiling or sidewalls
• Poorly sealed fan openings
• Gaps where the pad system meets the wall

Seal all leaks with caulk, foam, or tape. A tight house is essential for good airflow control.

Monitoring and Recordkeeping

Airflow measurement is not a one-time task. It is an ongoing part of house management. Set up a routine that gives you consistent data over time.

Daily Checks

Every day, check the static pressure gauge. It should be within the target range for your ventilation mode. A sudden change in static pressure signals a problem. If the pressure drops, you may have a fan failure or an open inlet. If it rises, you may have a clogged pad or a closed inlet.

Also check the evaporative cooling pads visually. Look for dry spots, algae growth, or mineral buildup. Address problems before they become severe.

Weekly Measurements

Once a week, take a set of airflow measurements. Use the same grid and the same procedure every time. This gives you a consistent dataset.

Record the date, time, bird age, outside temperature, static pressure, and ventilation mode. Also record which fans are running and any equipment changes you have made.

After Any Equipment Change

Whenever you change fans, belts, inlets, pads, or controllers, remeasure the airflow. Equipment changes alter the airflow pattern. You need new data to confirm the system works correctly.

Also measure after significant maintenance. Cleaning the fans and pads changes airflow. Your readings before and after maintenance tell you how much capacity you recovered.

Seasonal Measurements

Airflow patterns change with the seasons. Outside temperature affects air density, which affects fan performance and air speed. Measure at least once per season to confirm the house performs well across conditions.

Recordkeeping Format

Use a simple spreadsheet or logbook. Include these columns:

• Date
• Time
• Bird age
• Outside temperature
• Outside humidity
• Ventilation mode
• Static pressure
• Number of fans running
• Average air speed
• Maximum air speed
• Minimum air speed
• Uniformity (max minus min)
• Equipment notes
• Observations

Review your records monthly. Look for trends. Is air speed declining over time? That may indicate fan wear or pad clogging. Is uniformity improving after your changes? That confirms your maintenance is working.

Using Data for Decisions

Your airflow records help you make better decisions about ventilation. If air speed is below target on hot days, you know you need to improve fan capacity or reduce obstructions before the next heat wave. If uniformity is poor, you know where to focus your maintenance efforts.

The data also helps you evaluate the impact of changes. If you install new fans, the before and after measurements tell you how much improvement you gained. This justifies the investment and guides future upgrades.

When to Call a Veterinarian or Extension Agent

Most airflow problems are mechanical and you can fix them yourself. But some situations require professional help.

Respiratory Distress

If birds show signs of respiratory distress such as gasping, open-mouth breathing, or excessive panting despite adequate air speed, call a veterinarian. These signs can indicate heat stress that your measurements are not capturing, or they can indicate a respiratory disease.

High air speed does not always solve heat stress. If humidity is very high, evaporative cooling is less effective. The birds may still be too hot even with 700 fpm of air movement. A veterinarian can help you assess the situation and adjust your management.

High Mortality

If you see a sudden increase in mortality, especially during hot weather, call a veterinarian immediately. Heat stress can kill birds quickly. But so can disease. A veterinarian can determine the cause and recommend treatment.

Your airflow records will help the veterinarian understand the situation. Bring your recent measurements, static pressure readings, and ventilation settings to the consultation.

Unexplained Poor Performance

If feed conversion is poor, growth is uneven, or birds are not gaining weight as expected, and your airflow measurements look normal, call an extension agent. They can help you evaluate other factors such as nutrition, water quality, stocking density, and disease.

Sometimes the problem is not the average air speed but the distribution. An extension agent with experience in airflow evaluation can identify issues you might miss.

House Design Problems

If you have done everything right and still cannot achieve adequate airflow, the problem may be in the house design. The fan capacity may be too low for the house size. The inlet area may be insufficient. The house may be too wide for the fan system.

An extension agent or agricultural engineer can evaluate your house and recommend design changes. This is a significant investment, but it may be necessary to achieve the airflow your birds need.

Disease Outbreaks

Certain diseases spread more easily in houses with poor ventilation. If you suspect a disease outbreak, call a veterinarian immediately. Do not wait for your next scheduled measurement.

The USDA APHIS and WOAH provide guidance on reportable poultry diseases. If you see signs of a reportable disease, contact your veterinarian or state animal health official right away.

Frequently Asked Questions

What is the best anemometer for a broiler house?

A handheld rotating vane anemometer is the best choice for most broiler growers. It is durable, accurate in the 100 to 5,000 fpm range, and easy to use. Look for a model with a telescoping wand so you can reach bird level without bending. A digital display with an averaging function is helpful. Budget $100 to $400 for a quality unit.

How often should I measure air speed in my broiler house?

Measure at least once a week during production. Take additional measurements after any equipment change, after major maintenance, and during extreme weather. Daily checks of static pressure are also important. Consistent measurement gives you a baseline and helps you spot problems early.

What air speed do broilers need in hot weather?

Market-age broilers need 400 to 700 fpm in hot weather. Some high-density houses run 800 fpm or more. The exact target depends on bird age, outside temperature, humidity, and house design. Young birds need much less air movement than market-age birds. Use the table in this guide as a starting point and adjust based on bird behavior.

Why is my air speed lower at bird level than at waist height?

Air near the floor is slowed by friction with the litter and by the birds themselves. This is normal. The difference between waist height and bird level can be 100 to 200 fpm in a tunnel house. What matters is the air speed at bird level, because that is what the birds feel.

How do I improve air speed in my broiler house?

Start by cleaning the fans, pads, and inlets. Dirty equipment can reduce airflow by 20 to 30 percent. Check static pressure and adjust inlet openings. Raise feed lines and water lines to reduce obstructions. Seal air leaks. If these steps do not help, you may need more fan capacity or a house design change. Consult an extension agent for a professional evaluation.

What is the difference between air speed and airflow?

Air speed is the velocity of air movement, measured in feet per minute. Airflow is the volume of air moving through the house, measured in cubic feet per minute. Airflow equals air speed multiplied by the cross-sectional area of the house. Both matter. Air speed determines wind chill effect on the birds. Airflow determines how quickly heat and moisture are removed.

How does static pressure affect air speed?

Static pressure is the resistance to airflow. If static pressure is too high, the fans cannot move enough air. This reduces air speed. High static pressure is usually caused by dirty pads, restricted inlets, or obstructions. Low static pressure usually means air is leaking into the house. Both conditions reduce the effectiveness of the ventilation system.

Can I measure air speed without an anemometer?

You can get a rough sense of air movement with your hand or with a thin ribbon or tissue. But these methods are not accurate enough for managing a commercial broiler house. An anemometer is a necessary investment. A basic rotating vane unit costs less than one batch of birds and pays for itself through better performance.

Related Farming Guides

This section will be populated with links to related poultry farming guides on this site. Check back for additional resources on broiler house ventilation, litter management, heat stress prevention, and poultry house environmental control.

Related Clinical & Scientific Guides

• Poultry Farm Fencing: Materials, Design, and Predator Exclusion
• Broiler House Heating Systems: Types and Efficiency
• Broiler House Tunnel Ventilation Design and Operation

References

• FAO Poultry Production: https://www.fao.org/poultry-production-products/en/
• USDA APHIS Poultry Health: https://www.aphis.usda.gov/livestock-poultry-disease/avian
• WOAH Avian Influenza: https://www.woah.org/en/disease/avian-influenza/
• FAO Animal Production and Health: https://www.fao.org/animal-production/en/
• WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/

This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.