Why the first hot day isn’t so bad

With high temperatures predicted to be in the mid-70’s tomorrow in Southern Minnesota, many pork producers will be unprepared for change from winter to summer conditions. Fortunately, while the ventilation systems may not be fully prepped for their summer cycles, the physics of heat storage will keep pigs comfortable.

Concrete is a great heat ‘sink’. In the early 1980’s when there was a surge of interest in solar heating of farrowing houses and nursery rooms, used concrete slats were a preferred heat storage media. Their large thermal mass means they change temperature slowly.

With warm air temperatures predicted tomorrow, the large amounts of concrete in today’s production facilities means the facilities will remain relatively cool for the pigs. This is why production facilities respond differently to the same air temperatures in April and October.

In April, the concrete thermal mass is cool (some would say cold) coming out of the long winter so it moderates the temperature in the facilities, keeping conditions in the pig zone relatively cool even as air temperatures rise into zones that should cause heat stress.

In October, the concrete has had all summer to build up heat and as temperatures cool at night, conditions in the pig zone lag the fall in temperature due to the stored up heat in the concrete thermal mass.

Yes, it is time to prepare you summer cooling systems as they will be needed in the coming months. However, the large thermal mass of today’s facilities means an occasional day like tomorrow won’t impact performance as much as some may think.

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