SPRING VENTILATION CHECKLIST FOR FINISHER BARNS
As we look at the piled snow and another cold snap, I know from prior experience that we will be seeing some 50 degree days soon. They probably will come with night temperatures still 30 to 40 degrees colder than that, so we will experience large temperature variations. As we hit that first day of 60 degrees, will we be ready?
Some action items to prepare:
- Soffits: Some units have most soffits closed for the winter. They need to be opened. What is the total square inches of your inlets? You need about 50% more area than that available into the attic, most likely through the soffits. If the soffit screen is damaged or dirty put that on your to-do list.
- Fans: Many are covered for the winter. It is time to pull off the covers and double check their condition and functionality. If you have fans set up as emergency fans on separate thermostats, check that the thermostats still work and were not compromised with the winter humidity levels.
- Bandwidths: Over the cold months I usually see BWs widened (maybe 2° to go from minimum to 100%) so you do not trip an additional fan too quickly in cold weather. Summer settings we generally tighten these (maybe 1°) so we can step in additional fan power fairly quickly.
- Curtains: Many are secured up, mostly north sides. You do not want your first 50° day with only the south side operational, these must be free to move. Unsecure them and check their functionality. Power Drop curtain drop should be verified. Watch your curtain movement….. see below.
- Curtain run times: Many problems evolve from too far or too quick curtain movement. The general rule of thumb is 1” downward movement or ‘run time’ (regardless of how many seconds that is on your controller) and a ‘read interval’ of 2 minutes. This slower runtime and longer read interval allow the probe to react to the fact the barn has cooled some from the last move, without dropping more.
- Bait boxes: They may have been under snow, so spring is a good time to reload them with fresh bait.
- Static Pressure: No matter what fans are running, you should have some static pressure. The entry door should pull shut behind you. No pull = no static pressure. Door slams = too much. Static pressure tells you the inlets are in balance with the fans delivering a proper incoming air speed.
That is a quick list of problem areas to check before the weather allows field work!