Air dehumidification in an unit is a key element of effective air exchange in premises. In order to improve air quality inside buildings and to improve energy effectiveness of ventilation systems, a variety of technologies are used, from which one of the important ones is using heat exchangers.
In the context of units there are two main categories of exchangers: rotary and counterflow. Both of these types play a key role in the process of air dehumidification, allowing heat recovery and effective termination of moisture from air flow. This article entry will show you the importance of air dehumidification in an unit, focusing on the principles of rotary and counterflow heat exchangers and what role they play.
Air dehumidification process in the unit – How does rotary heat exchanger work?
In the case of rotary heat exchangers, the process of air dehumidification happens with the help of rotating around its axis heat exchangers or a single heat exchanger. Exchangers consist of thousands of lamellas in which air is moving. In one part of the exchanger fresh air from outside flows through and from the second one; ventilated air, it means dirty/ hot/ wet from inside of the building.
While the heat recovery system works, fresh air and ventilated air flow through separated canals, which are placed on two opposing sites of the exchanger, which rotates. Thanks to that, heat is transferred from one airstream to another, while keeping them separate, but also transferring moisture. This process takes place in such a way that warm and humid air from the house flows into the cooled lamella. This air is cooled in this place which leads to condensation of water.
In the case of rotary heat exchangers, humid air from inside the building is transferring its heat and moisture to fresh air from outside. In the result, fresh air is watered and at the same time warmed up thanks to retrieved heat and moisture. In turn, dirty air, after transferring its heat energy and moisture, from inside the building is discharged outside.
Rotary heat exchangers vs counterflow – Air dehumidification in heat recovery
In the case of counterflow heat exchangers, process of air dehumidification happens in a similar way to rotary heat exchanger, because, also as a result of cooling, the air ‘shrinks’ and leaves excess moisture on the lamella through which it flows and this flows by gravity to the drip tray in the unit. In the case of enthalpy, there is a membrane between the lamellas, allowing moisture to pass through, but blocking the path of odors and dirt from the air removed from the building. Heat also transfers from one air flow to another by transferring heat through material of exchanger.
In both cases, both in rotary heat exchangers and counterflow heat exchangers, the air dehumidification process happens in an effective way, enabling simultaneous heat recovery and reduction of moisture from ventilated air. It contributes to keeping a healthy and comfortable atmosphere inside the building.
As for the moisture itself, high humidity in indoor air can even lead to health problems. Scientific studies show the negative effects of an excessively humid environment on human health, which is similarly harmful to an excessively dry environment.
How does heat recovery handle problems of moisture in premises?
Excessive humidity inside buildings favors fungus and mold development, which can cause allergies, asthma and other health problems. Research conducted by the World Health Organization (WHO) and other scientific institutes indicate that exposure to fungus and mold can cause irritation of the respiratory system, allergy symptoms such as stuffy nose, cough, eye itching and exacerbate asthma symptoms in susceptible individuals.
Additionally, excessive humidity can contribute to development of mites and microorganisms, which are also factors of risk for health. Exposure to mites can cause allergy symptoms such as skin itching, rash, sneezing, and to people with asthma it can escalate its symptoms. On top of that, a humid environment favors the proliferation of bacteria, which can be dangerous to respiratory systems and general health conditions.
Excessively humid environment also favors condensation on walls and other surfaces. In turn this can cause building damages, such as discolouration, plaster decay, mold on surfaces and corrosion of metal components. Research results conducted by independent institutes and research centers confirm the negative effects of an excessively humid environment on the durability and stability of a building’s structure.
One study by a reputable scientific institute found that a damp environment can lead to a reduction in the strength of concrete and other building materials, which in turn can affect the structural integrity of a building. Other studies have confirmed that prolonged exposure to moisture can cause degradation of thermal insulation, leading to energy loss and increased running costs.
From this, it could be concluded that excessive humidity inside buildings has a negative impact on human health and the durability of structures. Exposure to mold, fungus, mites and bacteria involved with excessive moisture can lead to allergy symptoms, worsening of asthma and other health problems. In addition, condensation on walls and surfaces can lead to building damages. Research results confirm negative effects of an excessively humid environment to durability of construction and energy effectivity. That’s why effective heat recovery systems help with getting rid of moisture excess, preventing mold, fungus and other health problems from appearing and protecting building structure.
The use of a correctly executed heat recovery system, together with a properly sized unit, is key to regulating moisture and preventing it from accumulating excessively in the rooms, or simply drying them out.
