Cooling pads (panel chłodzący) — evaporative cooling in the heat
A cooling pad (panel chłodzący) is a wall of cellulose media through which air enters the house already cooled by water evaporation. In summer it is often the only cheap way to shave off a few degrees and save the flock from heat stress. We explain how it works, how to size pads to tunnel ventilation and when it really pays off.
verifiedFrom the team that has organised work on poultry farms for years.
What a cooling pad is
A cooling pad (panel chłodzący) is part of the air inlet in a poultry house through which incoming air passes through a wet, porous medium — most often cellulose. Water runs down the pad and evaporates, and evaporation absorbs heat from the air, so it enters a few degrees cooler. This is evaporative cooling, that is, cooling based on water evaporation. It works best on dry, hot days — exactly when birds struggle most.
Where and why it is used
Pads are mounted in the inlet wall of the house, usually together with tunnel ventilation: fans on the opposite wall pull air out, so fresh air must pass through the wet pad wall. This way the entire airflow entering the building is cooled, not just one spot. We cover the medium itself and its types in the article on evaporative pads in the poultry house.
Why it matters in summer
Birds do not sweat and shed heat mainly through breathing. In the heat, when house temperature rises above the comfort zone, birds fall into heat stress: they eat less, grow worse, lay fewer eggs and in extreme cases die. A few degrees less is a real difference between a calm and a disastrous day. That is why in summer a cooling pad can matter as much as heating in winter.
Pads are part of a larger climate system
A pad alone does nothing without working ventilation and control. It works together with efficient fans, and is switched on and regulated by a climate computer that watches temperature and humidity. On cooler days an alternative or complement can be heat exchangers, which recover energy without raising humidity. House climate is always a set of several elements, not a single device.
Everything recorded in DlaFerm.pl
How birds cope with heat shows in flock results — gains, feed use and mortality. In DlaFerm.pl you keep a digital Flock Card, so after the season you can judge whether cooling worked, and you have flock records in IRZplus at hand. You can create a farm account for free and start recording from the first hot day.
Cooling pads — how evaporative cooling works
From the type of medium to integration with the controller — here are six things worth understanding before you fit a cooling pad in your house.
Types of pads — usually cellulose
The most common is the cellulose pad: a glued medium of corrugated, impregnated paper that holds water well and gives a large evaporation surface. There are also plastic media, but cellulose dominates in poultry houses. Types and thicknesses of the medium (e.g. 10 or 15 cm) are described in the guide on evaporative pads in the poultry house — a thicker medium cools more but resists airflow more.
How it works — evaporation lowers temperature
Water from the top trough runs down the medium and wets it evenly. When dry, hot air passes through the wet pad, part of the water evaporates and takes heat away — the air leaves cooler but more humid. It is a trade-off: you gain degrees, you give up a rise in humidity. That is why evaporative cooling works best when the outside air is dry.
Key parameters — surface, air speed, temperature drop
Three things decide effectiveness: pad surface (it must be large enough for the house), air speed through the medium (too fast — water has no time to evaporate and the pad splashes) and the temperature drop achieved. In practice a few degrees are realistically shaved off; the drier the air, the larger the drop. Sizing the surface to fan capacity is the foundation.
Where and when to use it
Pads are switched on only in heat and only with dry air — on a humid, muggy day they give little and raise humidity. They work best in a climate with hot, dry afternoons. Outside the warm season the medium stays dry and the inlet works like an ordinary opening. It is a seasonal tool, not a year-round one.
Installation and integration with tunnel ventilation
A cooling pad makes sense combined with tunnel ventilation: fans at the end of the house pull air out, creating negative pressure that draws fresh air through the wet pad wall. This cools the whole stream. Without strong, directional ventilation the pads will not work — it is a system, not a single wall.
Integration with the controller
The water pump and flow through the pads are run by a climate computer: it turns cooling on once the temperature threshold is passed and keeps humidity within a safe range. A well-set controller cools when needed and eases off when muggy. Without automation it is easy to overcool the morning or push humidity too high in the afternoon.
Sizing, costs and servicing of cooling pads
Pads can be cheap to buy but need working ventilation and regular servicing. Here are six things to think through before you decide on a cooling pad.
Sizing to ventilation capacity
A pad is only as good as the ventilation that pulls air through it. The medium surface is sized to fan capacity and air speed in the house — too little surface with strong fans means airflow too fast, splashing and poor cooling. First tunnel ventilation, then sizing the pads to it, not the other way round.
Costs — low medium, running water and power
The cellulose pad itself is relatively cheap and installation is simple compared with other climate systems. Running costs are water (part evaporates, part circulates), power for the pump and fans, and periodic replacement of worn medium. It is usually the cheapest way to cool a house — solutions without evaporation cost more. Calculate the costs for your climate and the length of summer.
Servicing — water, algae and scale
A wet medium is an environment for algae and deposits, and hard water leaves scale that clogs pores and lowers cooling. You need clean water, regular cleaning, periodic drying of the medium and checking of the water distribution troughs. A neglected pad cools worse, lasts shorter and can harbour bacteria. Servicing is not optional but a condition of effectiveness.
Risk of high humidity
Every degree gained from evaporation is a rise in humidity in the house. On a muggy day pads will raise humidity so much that birds find it harder to shed heat — the effect can be the opposite of intended. That is why the controller must watch humidity, and in a humid climate it is worth considering heat exchangers as a complement, since they do not add water to the air.
Common mistakes
The most common slips are: pads without strong enough ventilation (no negative pressure, so no cooling), no servicing (scale and algae), switching on during a muggy day (humidity rises, heat does not drop) and no automation — manual control cannot keep up with the weather. A climate computer alone removes most of these mistakes if it is well set.
When it pays off
A cooling pad pays off where summer is hot and rather dry and the house already has tunnel ventilation — then at low cost you save flock results in the heat. In a cool or very humid climate the gain is small and the humidity risk large. Judge it from the data: when the Flock Card shows drops in gains on hot days, the investment usually pays back.
Frequently asked questions about cooling pads
How does a cooling pad work?add
Air drawn into the house passes through a wet, porous medium — most often cellulose. Water runs down the pad and evaporates, and evaporation absorbs heat from the air, so it enters the house a few degrees cooler. This is evaporative cooling, based on water evaporation. A side effect is a rise in humidity, which is why pads work best when the outside air is dry.
How much do pads lower the house temperature?add
They realistically shave off a few degrees, and the exact drop depends on air humidity: the drier and hotter the outside air, the larger the cooling. On a muggy, humid day the gain is small. Sizing the pad surface to ventilation capacity and the air speed through the medium also matter — too fast a flow lowers effectiveness.
Does a cooling pad increase humidity?add
Yes — it is an inherent effect of evaporation. Every degree gained from evaporative cooling means more water vapour in the house air. In a dry climate this is an acceptable trade-off, but on a muggy day excess humidity makes it harder for birds to shed heat. That is why pad operation should be run by a climate computer that watches both temperature and humidity.
Which pads to choose — cellulose or other?add
Cellulose pads dominate in poultry houses: they give a large evaporation surface, hold water well and are relatively cheap. A thicker medium cools more but resists airflow more, so it must be sized to the ventilation. Types and thicknesses of the medium are described in a separate guide on evaporative pads — the choice depends on the climate and fan capacity.
How do I service cooling pads?add
The key is clean water and regular cleaning: a wet medium favours algae, and hard water leaves scale that clogs pores and lowers cooling. You need to dry the medium periodically, check the water distribution troughs and replace worn medium. A neglected pad cools worse, lasts shorter and can harbour bacteria.
Are pads enough without tunnel ventilation?add
No. A cooling pad works thanks to the negative pressure that fans create in the house — it draws air through the wet wall. Without strong, directional tunnel ventilation there is no flow, so no cooling. A cooling pad is part of the climate system, not a stand-alone device, which is why ventilation is designed first and the pads are sized to it.
Check whether cooling helps your flock
Want to know if cooling pads really save results in the heat? Keep a digital Flock Card in DlaFerm.pl and compare gains and mortality on hot days. Create a free farm account and start recording from the first heatwave.
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