The keys to kid barn ventilation

The key to a good kid barn ventilation audit is to evaluate the air quality in many different scenarios. Weather can change the kid’s environment quickly. Monitoring air quality should be part of your daily checklist. If problems persist, enlist a trusted consultant to assess your options.

Daily checks:  Look, listen, smell and feel

Look: How are the kids utilizing the space in the pen? They will lie where they are most comfortable. Kids should use the entire space available and not bunch in one spot. Drafts, poor bedding and fly pressure can lead to bunching. Look at the bedding.  Ideally, you should not see the bedding actively move at the kid level.

Listen: What is the environmental noise, especially any type of mechanical ventilation? You can often hear if barn fans are not functioning properly. Fans should not make surging noises unless the wind is strong. If you hear surging noises, it may indicate that your hood is not the right size. Fans – like all other equipment – need maintenance. They should be cleaned at least once a year, preferably in late summer or fall.

Smell: Is the air fresh and clean? Conduct this test where the kids lie down. Get down to the kid’s nose level and smell what it is smelling. A smelly spot could indicate a ventilation dead zone or simply a need for more bedding. Bedding plays a big role in air quality.

Feel: Spend some time in the pens with kids to evaluate the air movement at the kids’ level.  The goal is to keep kids cool and eliminate stagnant air at the kid level.  A good air speed is 60 feet per minute. Do you feel drafts? If you find areas with no air movement, find a way to address the problem.  Incorporating some sort of fan system, even just large floor fans, can be beneficial to the health of the kids.

Tools to help

Put some metrics to your senses. A few tools can help put numbers to your observations.

1. Wind meter and anemometer
A wind meter will help you identify areas of concern as it measures air speed and variability in a barn. Again, focus on areas where the kids lie down. You should also measure areas by ventilation tubes and fans. Sometimes a hotwire anemometer is more sensitive and provides better information than a wind meter. When using these tools, it is important to take measurements in various weather conditions and areas of the barn, including the walk area. The goal is to have consistent numbers throughout the facility. Work with a trusted consultant to evaluate the data you collect.

2. Bug fogger
Another option is to “smoke” the barn. We use mineral oil in a bug fogger to fill the barn with smoke.  Ideally, we would fill the barn with smoke through tube fans if installed. Not only does this show how air moves in the barn, but it also helps evaluate the tube ventilation system. In the tubes, we are looking for even distribution, air leaks at connection points, air surging from the holes, and where the air goes.

When smoking a barn, we determine the number of air changes (how often the air completely turns over) per hour.  In cold weather, air should change four to six times per hour.  In the summer, it should change 40 times per hour. To measure this, start a timer once the last puff of smoke enters the barn. When the air is clear, stop your timer.  Divide 60 minutes by the number of minutes it takes for the smoke to clear.  For example, if it takes 15 minutes for the smoke to clear, the barn has four air changes per hour (60 / 15 = 4).

Safety is of the utmost importance when smoking a barn. Work with a consultant who is experienced in the process and knows how to use the tools in a safe manner.

3. Ammonia strips
Ammonia strips can be used to measure ammonia concentration, which can affect health and growth, and evaluate bedding moisture. Tear off a 1-inch piece of ammonia strip and wet it with clean water. Wave the strip 1 foot above a bedded pack area for 20 to 30 seconds and then wait 15 seconds. Compare the strip color with the color chart on the package. The target is less than 5 ppm ammonia in kid facilities.