How and what we breathe at home

Often underestimated, the problem of environmental pollution is fundamental for determining the level of well-being inside homes. The rooms of our house are – as a matter of fact – places of proliferation of molds and bacteria, as well as rich in other substances harmful to our health. Coexistence with these phenomena must cause concern because they are harbingers of very serious consequences (especially for health); very often taken into consideration only when they have reached such a level of severity that they have already produced negative consequences and require heavy resolving interventions. The quality and control of the air we breathe at home, therefore, are essential, along with other factors that obviously contribute to the quality of the home climate such as temperatures and bad smells.

The origin and consequences of the problem

The phenomenon of the spread of mold in the home is mainly linked to the lack of indoor air exchange. Ventilating a room correctly and frequently prevents mold from forming. Other factors, however, such as excessive humidity and heat, can favor the formation of mold. The formation of humidity and mold in the home is a problem that can arise for various reasons, such as the presence of thermal bridges or excessive environmental humidity. It manifests itself with spots on the walls or damage to the plaster. The problem of humidity in homes is not only aesthetic, in fact humidity and mold are a potential danger to the health of those who live in the house.

In fact, science has shown that exposure to mold and humidity in the home is associated with the increased presence of respiratory symptoms, asthma and functional respiratory damage. The Italian Ministry of Health itself reports that the overall results of studies on 6-12 year olds confirmed the relationship between visible mold and children’s nocturnal and diurnal cough and, in more crowded families, the relationship with asthma and sensitization to inhalant allergens.

The pathologies attributable to the presence of mold and therefore of spores dispersed in the air are:
  • Respiratory allergies: the respiratory allergic reaction can manifest itself with rhinitis, cough, cold, conjunctivitis. 
  • Allergic rhinitis (allergic cold or hay fever): manifests itself as inflammation and congestion of the nasal passages, eye irritation, cough, fatigue and headache. 
  • Asthma: a potentially serious illness that manifests itself as intense breathing and a feeling of suffocation. 
  • Conjunctivitis: occurs with red and inflamed eyelids and profuse lacrimation. 
  • Physical fatigue: ie muscle aches and stiffness, joint pain, feeling of fatigue, tiredness and weakness. 
  • Dermatitis: dermatological problems such as peeling of the skin, rashes and itching. 
  • Difficulty concentrating: it is more difficult to concentrate, with possible negative effects on memory, dizziness and headaches.
About forced ventilation in a blind bathroom

We speak of forced ventilation especially for bathrooms with no window.
In the cases of construction or renovation of bathrooms, there are regulations created ad hoc that establish the rules for correct design and installation. Article 7 of the 1975 Ministry of Health Decree provides that “the bathroom must be equipped with an opening to the outside for air exchange or equipped with a mechanical suction system.”
The Building Regulations and the Hygiene Regulations complete the regulatory framework thanks to specific devices dedicated to building hygiene. In general, with the use of forced ventilation devices, a minimum air exchange coefficient of 6 volumes/hour must be ensured, if the device is always active, or 12 volumes/hour if in forced intermittent suction with automatic control suitably timed to ensure at least 3 air exchanges for each use of the room. It is possible to install a VMC system equipped with fans for forced ventilation that allow you to correctly manage the air exchange in the rooms.

The advantages of bivalent odor/vapor extraction

As an alternative to the ventilation fan directly connected to the VMC system, the ideal and innovative solution is to equip the bathroom with a bivalent extractor directly connected to the flushing pipe of the toilet flush cistern. In this way, it will be possible to obtain a more precise and direct extraction, both of the vapors generated with the use of domestic hot water, and of the odors generated in the bodily functions.


  • UNI EN 13141-8: 2014 Standard for Building Ventilation (Double flow)

It defines the laboratory test methods and test requirements for verifying the aerodynamic, thermal and acoustic performance, and the electrical power of a non-ducted mechanical intake and exhaust ventilation unit used in a single room. The purpose of this European Standard is not to assess the quality of ventilation, but to test the performance of the equipment.

  • UNI EN 13141-11: 2015 Standard for Building Ventilation (Single Flow)

Establishes the verification rules for single flow positive pressure ventilation systems. Specifies measurements of aerodynamic, acoustic and electrical power performance under test conditions for ducted / non ducted ventilation units, operating continuously in single rooms or in housing in residential ventilation. 

  • UNI EN 13142: 2013 Standard for Ventilation of Buildings

Specifies the performance characteristics of the components / products that may be necessary for the design and sizing of residential ventilation systems in order to ensure predetermined comfort conditions of temperature, air speed, humidity, hygiene and noise in the occupied area.

  • UNI 10339: 1995 Standard for Ventilation of Buildings (Double Flow)

It provides a classification of the plants, the definition of the minimum requirements and the values ​​of the reference quantities during operation. It applies to aeraulic systems intended for the well-being of people, however installed in closed buildings, with the exception of:
– systems for the winter climatization of buildings used for industrial or craft activities;
– plants intended for different purposes, for example those for the preservation of perishable products and / or for the creation of conditions suitable for particular industrial processes (process plants);
– winter heating only and summer cooling systems without mechanical introduction of external air.

  • ASHRAE 62.1 / 62.2: 2019 American Society of Heating, Refrigerating and Air-Conditioning Engineers

They are the recognized standards for ventilation system design and acceptable indoor air quality (IAQ). Expanded and revised for 2019, both standards specify minimum ventilation rates and other measures to minimize adverse effects on occupant health.


How VMC works

VMC Controlled Mechanical Ventilation, according to ASHRAE 62.1-2020 is defined as “the process of introducing and/or extracting air and/or towards a confined roomo with the aim of controlling the levels of pollutants, humidity or temperature” . For a residential building, the VMC system is that system dedicated to continuous air exchange that must provide new clean air. Here, in summary, how it works! A low-power consumption heat recovery fan constantly introduces new air into the house, taking it from the outside, filtering it, and removing pollen and pollutants. After passing the heat exchanger, the new clean air is channeled throughout the house through pipes or ducts and introduced into the rooms by means of the vents. The introduction of fresh air tends to be placed in rooms of the house where humans carry out activities such as staying and resting, therefore living areas and sleeping areas. In these rooms (living rooms and bedrooms) the main air pollutants are CO2 and water vapor in standard concentrations. The extraction of exhausted and unhealthy air is instead expected in the rooms where the activities carried out by people (cooking, washing, washing clothes) lead to a greater production of water vapor, CO2, and odors. Hence, mainly kitchens and bathrooms. The air extracted passing the heat exchanger releases its temperature before being expelled outside, in this way the new and healthy air that enters gains heat. This process of heat exchange and recovery contributes significantly to the containment of the costs of keeping the house heated. The VMC system is designed to provide balanced and continuous ventilation, reducing consumption through high energy recovery (estimated at 90%), avoiding the opening of windows or the use of small extraction devices.

Types of VMC systems

VMC systems can be divided into two categories, decentralized and centralized. For Bampi it is not important to evaluate which is the best system, but to promote knowledge and awareness on the topic of ventilation in domestic environments. Currently, in the Bampi MECHANICAL SYSTEMS catalog there are solutions that belong to centralized VMC systems with the adoption of the heat exchanger.

Characteristics of a centralized VMC system

A dual-flow VMC system involves invasive installation work, so it must be considered in the case of new buildings or in building renovation interventions that make it possible to create traces in floors and walls or in any case (in the case of curtain walls with plasterboard) to have volumes available for the transit of ducts and the installation of grilles and vents. The dual flow centralized VMC works with independent ducts: one line dedicated to the delivery of new air and the other intended for the recovery of exhausted and unhealthy air.

The advantages of centralized VMC
  • Continuous air exchange extended to the whole house
  • Constantly healthy climate in domestic environments
  • Uniformity and balancing (equivalence of inlet and outlet flow rates) avoiding putting areas of the house under pressure or depression
  • Achievement of the air flow rates necessary to meet the ideal temperature and humidity conditions
  • Only machine to be maintained
  • High energy yield
  • Reduced electricity consumption
  • Silence
  • Possibility of integration with air conditioning systems in conjunction with heat pumps
  • Improvement of the overall energy balance of the building alongside air conditioning machines for air handling with cooling / heating functions in heat pump
The fundamental role of the heat recovery unit

A dual flow VMC system finds its maximum efficiency when it is combined with a heat recovery unit, that is a machine that allows you to preheat the new incoming air by absorbing the heat from the outgoing air. We are talking about a cross flow heat exchanger; that is, the energy contained in the air extracted from the house is recovered and transferred to the air introduced from the outside. In this way it is possible to reduce the energy consumption of the building.


To regulate the level of indoor humidity and thus hinder the formation of mold and evacuate harmful substances from the rooms, as well as evacuate odors and vapors from the bathroom, it is necessary to exchange the indoor air effectively and continuously. For proper air exchange it would be necessary to open the windows at least once an hour. Unfortunately, this practice is difficult to prosecute due to a series of factors:

  • considerable commitment of the user
  • limitation of privacy
  • thermal dispersion
  • introduction of noises
  • entry of pollutants
  • entry of insects and pollen

The ideal solution is the installation of a Controlled Mechanical Ventilation system, capable of continuously exchanging the air in an indoor environment. Centralized VMC is that system with which you can manage the air change in an intelligent way, especially with the technologies currently available. A newly built house with a good level of energy and acoustic classification is airtight. For the purposes of energy saving and sound insulation, solutions are envisaged in the design and construction phase that eliminate all thermal and acoustic bridges. In such a condition, thermal gradients and natural drafts do not exist and therefore there is a real risk of experiencing an unhealthy environment with polluted air.

And for the extraction of odors and vapors from bathrooms?

Bampi proposes an innovative device capable of ensuring a timely and immediate expulsion of odors and vapors generated in the use of the sanitary ware in a bathroom. SNIF is an odor / vapor extractor directly connected to the toilet cistern. Its use guarantees rapid and effective extraction, avoiding the user opening the window to ventilate. This technical solution presents itself as an advantage because it reduces heat losses, favoring the correct and healthy functioning of a VMC system. Furthermore, SNIF appears very useful in the conditions of blind bathrooms, or in the absence of a window.

Components of the centralized dual flow VMC system

Let’s see briefly what are the main components of the VMC system proposed by Bampi, suggesting that you deepen the subject by consulting the technical data sheets and manuals in the download area of ​​this site.

Dual flow centralized heat recovery units

The heat recovery unit draws the air from the outside and filters it before introducing it into the home through the ducts. The same machine synchronously manages the expulsion of stale air from the indoor environment, disposing of water vapor and expelling carbon dioxide and volatile micropollutants. The size of the heat recovery units for VMC varies depending on the surface (and volume) of the house in which the air is exchanged. The machines have different characteristics and performances according to their intended use.

Rigid antibacterial soundproof duct for air ducting

The quality of the air transported and the efficiency of a VMC system are also determined by the type of pipes used for the distribution of the system. In addition, there is also a considerable aspect, linked to the acoustic impact that this system can have on living comfort. For these reasons, Bampi proposes the use of the POLO-KAL NG soundproof system for this application, capable of offering a range of diameters from 32 to 250 millimeters with a wide range of fittings. Moreover, in a completely exclusive way for the plumbing and heating market, ad hoc pieces can be made in the factory to ensure full compatibility of gradations and diameters, especially in particular construction site conditions. The POLO-KAL NG system for VMC allows installation in all conditions: anchored to the ceiling, embedded in the slab or within foundations.

Antibacterial soundproof flexible duct for air ducting

To complete the VMC range, a flexible duct made of polymer structured in double wall, corrugated external color BLUE POLO-KAL NG and internal smooth transparent, is proposed, suitable for being embedded in walls, floors and plasterboard structures. Obviously, the corrugated pipe is perfectly compatible with the rigid system of pipes and fittings POLO-KAL NG.


Among the plenums, Bampi offers three different solutions in the catalog, depending on the plant opportunities:

  • Delivery PLENUM in galvanized steel
  • Delivery PLENUM in modular and reversible galvanized steel
  • Delivery PLENUM in reinforced polypropylene soundproofed POLO-KAL NG series

Range of vents in paintable natural anodised extruded aluminum, which can be installed both on the wall and on the ceiling, including calibration damper and galvanized grille-holder plenum.


Intake grilles in paintable natural anodised extruded aluminum, which can be installed both on the wall and on the ceiling, including a Class G3 acrylic fiber filter and fixing / extraction frame.