Control of a passive ventilation system for a building, a passive ventilation system for a building, and a building with a passive ventilation system

Abstract

To provide a passive-ventilation system that maintains a thermally-comfortable internal environment and increases the energy efficiency of ventilation.SOLUTION: A method for controlling a passive ventilation system of a building includes the steps of: measuring an outdoor air temperature of air around the building; measuring an indoor air temperature of at least one zone within the building; calculating a temperature difference by subtracting the measured outdoor air temperature from the measured indoor air temperature; and, when the temperature difference is larger than zero, controlling a state of at least one passive-ventilation device of the passive ventilation system to be in any of a closed state, an open state, and one of one or more intermediate states between the closed and open states. Each state corresponds to one value of an open fraction value of at least one zone in the building, which varies between zero and 1. The opening fraction value is set to an upper fraction limit equal to 1, if the temperature difference is lower than or equal to a preset lower temperature difference limit, to a lower fraction limit greater than or equal to zero and less than 1, if the temperature difference is larger than or equal to a preset upper temperature difference limit, and otherwise, to a value of a passive-ventilation function of the temperature difference, which monotonically decreases with increase of the temperature difference.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to control of a passive ventilation system for a building, a passive ventilation system for a building, and a building with a passive ventilation system. [Background technology]

[0002] Controlling ventilation in buildings is an important field of research, particularly with regard to "passive" or "natural" ventilation in buildings. For example, U.S. Patent Publication No. 2009 / 0129999 proposes a method and system for controlling ventilation in an indoor area of ​​a building, in which the indoor area is ventilated by active mechanical ventilation and passive natural ventilation according to a ventilation mode selected from among a plurality of ventilation modes using a set of adjustable control parameters and measurements from at least one sensor. Each ventilation mode is associated with a set of adjustable control parameters, each having an adjustable value selected from a group of adjustable values ​​depending on the mode, and / or a set of fixed control parameters, each having a fixed value depending on the mode. Control of mechanical ventilation and natural ventilation is achieved by comparing measurements from the sensor with the corresponding values ​​of the control parameters for the ventilation mode, so as to obtain a desired indoor climate defined by the ventilation mode.

[0003] Another passive ventilation control system is disclosed in US Pat. No. 5,699,949, in which individual vents are provided in sets, with each set of vents aligned approximately vertically through multiple floors or the entire height of a building.

[0004] US Pat. No. 5,629,999 discloses another computer-controlled method for controlling internal climate comfort by natural ventilation in living areas of buildings occupied by human occupants.

[0005] Patent Document 4 proposes using a simple mechanical device that senses outdoor temperature and wind force to control ventilation duct outlets. This method automatically controls air exchange to eliminate cold air entering the building.

[0006] Further general background on natural or passive ventilation is provided in US Pat. No. 5,629,999 and US Pat. No. 5,629,999.

[0007] Non-Patent Document 1 investigated the impact of various window operations on the energy saving potential in mixed-mode office buildings. The window operations were based on the predetermined position of the window, resulting in electricity consumption savings of approximately 10% to 72% based on the climate and window opening. The energy saving potential of mixed-mode buildings has also been discussed in other studies, such as Non-Patent Document 2 and Non-Patent Document 3. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2013 / 107461 [Patent Document 2] US Patent Application Publication No. 2019 / 331355 [Patent Document 3] U.S. Patent No. 6,699,120 [Patent Document 4] U.S. Patent No. 4,182,487 [Patent Document 5] European Patent Application Publication No. 3578893 [Patent Document 6] Japanese Patent Application Laid-Open No. 2017-180960 [Non-patent literature]

[0009] [Non-Patent Document 1] H. Wang and Q. Chen, "A semi-empirical model for studying the impact of thermal mass and cost-return analysis on mixed-mode ventilation in office buildings," Energy and Buildings 67 (2013) 267-274 [Non-patent document 2] S. Ezzeldin and SJ Rees, "The potential for office buildings with mixed-mode ventilation and low energy cooling systems in aired climates," Energy and Buildings 65, (2013) 368-381 [Non-patent document 3] F. Babich et al., "A new methodological approach for estimated energy savings due to air movement in mixed-mode buildings," Proceedings of Buildings Simulation Applications, 2007: 3rd IBPSA-Italian Congress, Bolzano, 2017 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, in recent years, there has been growing interest in controlling natural or passive ventilation to achieve a thermally comfortable interior environment. Control of natural or passive ventilation is carried out by adjusting the opening of corresponding passive ventilation devices on the respective building facades. Such openable passive ventilation devices can be windows, dampers, grilles, vents, etc.

[0011] This leads to a technical problem, the objective of which is to solve: how to increase energy efficiency in the ventilation of buildings while maintaining a thermally comfortable internal environment. [Means for solving the problem]

[0012] The technical problem to which this is directed is solved by the subject matter of the independent claims. Advantageous embodiments are evident from the dependent claims, the description and the drawings.

[0013] One aspect relates to a method for controlling a passive ventilation system, also referred to as a natural ventilation system, of a building. The method includes the steps of measuring the outdoor air temperature of air in the building's surroundings and measuring the indoor air temperature of at least one zone, i.e., one or several zones, within the building. The zones may be referred to as thermal zones. A room, a hall, a corridor, or a staircase of a building may be considered an exemplary thermal zone. The respective temperatures may be determined by measuring temperature sensors in the passive ventilation system or by accessing a corresponding database, e.g., a building's surrounding temperature database, if accessible via the Internet. The outdoor air temperature and / or the indoor air temperature may be determined as an averaged air temperature. If the method is applied to multiple thermal zones within a building, the internal air temperature of each zone, in particular the average internal air temperature, may be used to control the passive ventilation devices of the respective zones. In the case of multiple thermal zones, the control of the states of the passive ventilation devices may be performed individually, i.e., the states of the passive ventilation devices may be controlled independently of each other.

[0014] A temperature difference is calculated by subtracting the measured outside air temperature from the measured indoor temperature. If the calculated temperature difference is greater than zero, preferably in combination with the outside air temperature being higher than a given ventilation setpoint, the state of at least one passive ventilation device of the passive ventilation system associated with one, some, or all of the at least one zone within the building is controlled to be either closed, open, or one of one or more intermediate states between the closed and open states, where each state corresponds to a percentage opening value of the respective at least one zone within the building, ranging from 0 to 1, with 0 corresponding to the closed state and 1 corresponding to the open state. The association of each passive ventilation device with each thermal zone means that the respective passive ventilation device is configured for fluid communication between the corresponding zone or zones within the building and the building's ambient environment. Thus, one or more passive ventilation devices may be associated with each passively ventilated zone. The intermediate states may be, for example, 25% open, 50% open, and 75% open to achieve a graduated opening control.

[0015] Next, the state of the corresponding at least passive ventilation device is controlled by setting an opening rate value, where the opening rate value is set to an upper rate of 1 if the calculated temperature difference ΔT is equal to or less than a preset lower limit temperature difference k, or to a lower rate l which is equal to or greater than 0 and less than 1 if the calculated temperature difference ΔT is equal to or greater than a preset upper limit temperature difference m, or to the value of a passive ventilation function f(ΔT) of the calculated temperature difference if k≦ΔT≦m. The passive ventilation function monotonically decreases as the calculated temperature difference increases.

[0016] If the calculated temperature difference is not greater than 0 (and / or a given ventilation set point), the state of the controlled passive ventilation device(s) may remain unchanged or may be set to an open or closed state.

[0017] This provides the advantage of controlled operation of the passive ventilation system resulting in a thermally comfortable interior environment for the occupants with less reliance on active mechanical systems, thus helping to reduce energy consumption. The use of predetermined states or positions of each passive ventilation device with calculated temperature differences provides a simple and dynamic control scheme, i.e., a simple and reliable way to control the opening of the passive ventilation devices at given indoor and outdoor environmental conditions. Measuring, specifically repeatedly measuring, i.e., dynamically, the indoor air temperature of the corresponding zone in the building allows the passive ventilation system to adapt to the situation at hand, resulting in the implementation of a simple feedback loop, thereby reducing energy use. When the outside air temperature reaches a given or pre-set ventilation setpoint lower limit (T LL,HSP ) ensures that there is a thermodynamic benefit to ventilation.

[0018] In an advantageous embodiment, the state of the at least one passive ventilation device is determined by measuring both the outdoor air temperature and the indoor air temperature below a lower set point, i.e., a heating set point T LL,HSP and the upper set point, i.e., the cooling set point T UL,CSP and the temperature is controlled via setting the opening percentage value as described above only if the temperature is within the range between 0.01 and 0.1, otherwise the temperature is set to the closed state. In particular, the heating set point and the cooling set point can be set as dynamic set points according to a formula depending on the comfort temperature, and the comfort temperature can be set according to a moving average outside temperature T, such as the 7th day moving average outside temperature, rm Additionally or alternatively, the heating and cooling set points may be set as dynamic set points according to any of the known standards such as ISO17772, EN16798, EN15251B, or ASAHRAE. This is exemplarily shown in the table below, where T UL,CSP represents the cooling set point, and T LL,HSP represents the heating set point, and T rm is the outdoor temperature measurement T intis expressed as the measured temperature of outdoor air. For example, according to the ASAHRAE standard, the comfort temperature is 0.31T rm Defined as +17.8°C.

[0019] [Table 1]

[0020] The outdoor moving average temperature is, for example, T rm =t ed-1 +0.8*t ed-2 +0.6*t ed-3 +0.5*t ed-4 +0.4*t ed-5 +0.3*t ed-6 +0.2*t ed-7 / 3.8 It can be defined by:

[0021] where t ed-1 represents the daily average outdoor temperature of the previous day, etc. The dynamic set point ideally varies daily and can therefore be optimized for all climates throughout the year.

[0022] This offers the advantage of a dynamic system that adapts to the climate around the building on a global scale and to indoor temperature measurements as feedback on a local scale, thus ensuring energy savings and thermal comfort in a simple way.

[0023] In particular, the state of at least one of a window (or a set of windows), a damper (or a set of dampers), a vent (or a set of vents), or a grille (or a set of grilles) can be controlled as a state of at least a passive ventilation device. In other words, a passive ventilation device can be or include at least one of a window (or a set of windows), a damper (or a set of dampers), a vent (or a set of vents), or a grille (or a set of grilles). Thus, the proposed method can be easily applied to known passive ventilation devices, since the corresponding state of a known passive ventilation device or set of passive ventilation devices can be defined as a closed state, an open state, or an intermediate state according to the definitions provided above.

[0024] The intermediate states of a set of passive ventilation devices may correspond to a combination of open and closed states of the devices in the set. For example, a set of two windows may be set to a 50% open state by opening one window and closing the other. This has the advantage that a simple control mode of the individual windows is sufficient to implement the described control scheme.

[0025] In a particularly advantageous embodiment, a determination is made as to whether at least one zone controlled by a passive ventilation device is occupied and / or is scheduled to be occupied at a given time in the future, and the state of the at least one passive ventilation device is controlled by setting a percentage open value only if the respective zone is occupied and / or is scheduled to be occupied at a given time within a preset elapsed time, and is set to a closed state otherwise. The preset elapsed time may be set to include several hours, such as two or one hour, or as little as 30 or 15 minutes. This provides the advantage of increased safety by preventing the opening of one or more respective passive ventilation devices when no one is present. Furthermore, when a zone is unoccupied or not scheduled to be occupied, ventilation has a relatively low priority, which is reflected in the control strategy.

[0026] In another advantageous embodiment, it is determined whether the outdoor air temperature around the building exceeds an upper outdoor temperature limit within a predetermined elapsed time, for example according to a forecast obtained from the Internet or another service. If so (and in particular only if so), the state of at least one passive ventilation device is set to a state corresponding to a percentage opening value higher than the percentage opening value of the state of the at least one passive ventilation device corresponding to the determined outdoor temperature for the current time, or lower than the percentage opening value of the state of the at least one passive ventilation device corresponding to the outdoor temperature for the current time. This has the advantage that zones within the building can be pre-cooled in the case of a higher percentage opening, or cold air can be trapped in the case of a lower percentage opening, thereby reducing the use time of the mechanical system. In particular, the state of at least one passive ventilation device can be set to a higher percentage opening value in a first time period and a lower percentage opening value in a second time period following the first time period. This combines the above advantages.

[0027] In another advantageous embodiment, the lower limit percentage l is set to a value greater than 0 if a preset criterion is met, and is set to 0 if said criterion is not met. The criterion preferably includes that at least one zone corresponding to the controlled passive ventilation device is occupied or is to be occupied according to a preset schedule. Thus, a minimum ventilation can be guaranteed when the zone is to be used or is to be used by a person.

[0028] In a particularly advantageous embodiment, the passive ventilation function f is a linear function of the calculated temperature difference ΔT, which offers the advantage of a particularly simple system that nevertheless solves the technical problem at hand very well.

[0029] In particular, the linear function is proportional to the difference obtained by subtracting the upper temperature difference limit m from the calculated temperature difference ΔT, preferably proportional to or equal to said difference divided by the difference obtained by subtracting the upper temperature difference limit m from the lower temperature difference limit k, i.e. f prop.(ΔT-m) / (km). This particular linear function is particularly advantageous.

[0030] In an alternative embodiment, the passive ventilation function f is a function proportional to the inverse square root of the product of a variable a1 and the calculated temperature difference ΔT, or proportional to the inverse square root of the sum of the product of another variable a0 and a first variable a1, which is the calculated temperature difference ΔT. Here, the passive ventilation function is limited to a maximum value of 1 or equivalent, i.e., the value of the passive ventilation function f is set to 1 when the respective equation would actually yield a value greater than 1. This takes advantage of taking into account further limitations or characteristics of the specific configuration, providing advantages like the linear function described above.

[0031] In particular, the variables a0 and a1 are determined by the desired total airflow m through at least one passive ventilation device. t In particular, the total air flow rate m t is m t 2 =m b 2 +m w 2 and m b is the air flow rate due to buoyancy, and m w is the air flow rate due to wind.

[0032] Referring to CIBSE guide B, heating, ventilation, air conditioning and fluctuations, London, UK, 2005, the total air flow rate required for a comfortable environment is: Q g =m t * C P * (T int -T UL,CSP ) The total internal heat gain Q can be given as g can be calculated based on the formula for

[0033] Q in the formula g is the total heat gain in watts, which is determined by the machinery operating in the ventilated space, the number of people in the space, sunlight, etc. P is kJ / (kg * is the specific heat capacity of air in K, and T int is the internal temperature measurement in °C that can be averaged, and T UL,CSP is the cooling set point in °C. m b =C d * A w * [(2 * ΔT * h * g) / (T av +273)]^2, m w =0.05 * A w * V r , and m t 2 =m b 2 +m w 2 can provide a specific passive ventilation function, where airflow m is m 3 / sec, and A w is the effective area of ​​the window in square meters, h is the vertical distance in m between the centers of the openings of the different passive ventilation devices in each zone (this is 0 if there is only one passive ventilation device), and g is m / s 2 is the acceleration due to gravity in units of T av is the average of the measured outdoor and indoor temperatures in °C, and V r is the wind speed around the building in m / s.

[0034] Therefore, the effective area of ​​the window A w teeth, Aw =m t / {0.05 2* V r 2 +C d 2* [2 * ΔT * h * g / (T av +273℃)] 1 / 2 (Formula A) It can be calculated as:

[0035] Here, Q g and / or C d can be predetermined or calculated according to specific knowledge or assumptions for each zone. d is a dimensionless number used to account for the constriction of the streamlines after the flow path through the opening, i.e., through the thermal zone being ventilated. The discharge coefficient is therefore a function of the opening shape of each passive ventilation device. The largest ratio of cross-sectional area to perimeter occurs for circular openings, and therefore the discharge coefficient decreases as the opening shape becomes less circular. The discharge coefficient C for a standard circular sharp-edged opening is d is often given as 0.61. See Jones et al., "A review of ventilation opening area terminology," Energy and Buildings 118 (2016) 249-258. For single-way ventilation, a typical value found in the literature is 0.25, and for two-way ventilation, C d ranges from 0.26 to 0.9. See Awbi HB, "Ventilation of buildings", 2nd edition, 2003, or CIBSE Application Manual, 2005: "Natural ventilation in non-domestic buildings" and CIBSE Guide A: "Environmental design", 2015. 0.5 to 0.6 m 2It has been shown that for window areas of 100 mm, the discharge coefficient can vary from 0.6 to 0.8, while for smaller window areas, the discharge coefficient tends to be higher, between 0.8 and 1.0. For dampers, the discharge coefficient typically ranges from 0.4 to 0.6, depending on the geometric characteristics of the metal louvers, such as their shape and angle. For a typical rainproof louver with a 45° angle, the discharge coefficient can range from 0.3 to 0.5. See Heiselberg P and Sandberg M, "Evaluation of Discharge Coefficients for Window Openings and Wind-Driven Natural Ventilation," in International Journal of Ventilation: ISSN 5(1), 2006, 1473-3315.

[0036] Accordingly, the passive ventilation opening percentage value (and therefore the state of the passive ventilation device that best achieves the ideal effective area) is determined by the predetermined maximum openable geometric area A of each at least one passive ventilation device of the passive ventilation system. m The opening percentage value is given by (equation A) divided by A. w The value of A max If smaller than A m A divided by w and A w A max If it is greater than or equal to 1, it is 1.

[0037] This has the advantage that the passive ventilation system is not only controlled based on temperature differentials, but also takes into account the difference in air density between inside and outside and the specific setup of the facility to optimize the total flow rate through the ventilated space.

[0038] Preferably, the wind speed V r can be measured by wind sensors in passive ventilation systems, and / or the thermal gain Q gis set or calculated depending on whether at least one zone is occupied and / or is scheduled to be occupied at a given time in the future, particularly by how many people. This may be determined by a corresponding occupancy sensor in the at least one zone or by an occupancy schedule. This further contributes to the above-mentioned benefits, i.e., energy savings, while providing a comfortably ventilated space in the building.

[0039] According to the proposed method, natural ventilation within a building can be achieved by selecting the (effective) opening area, i.e., state, of each passive ventilation device of a passive ventilation system based on a specific setpoint temperature and given environmental conditions, such as outdoor and indoor air temperatures. However, wind, outdoor and indoor relative humidity, pollen levels, etc., can also be taken into consideration. For example, whether natural ventilation is appropriate for improving indoor comfort can be checked by checking the respective criteria, such as wind, outdoor and indoor relative humidity, and pollen levels. For example, at an initial stage, it can be checked whether the pollen level in the environment is below a given threshold for a good condition, and / or whether the wind level in the environment is below a given threshold for a good condition within the building, and / or whether the outdoor and / or indoor relative humidity is within a predetermined acceptable range. The proposed method can then be adapted so that passive ventilation is enabled only if passive ventilation contributes to a good condition within the building, i.e., if the criteria are below the respective thresholds and / or within the respective acceptable ranges. Regarding humidity levels, the acceptable range can be established as 30% to 70% relative humidity (Berglund, G. (1998) "Comfort and Humidity", ASHRAE Transactions, pp. 35-41; Arens, E.A., Xu, T., Bauman, F., and Oguro, M.). (1999) "An investigation of thermal comfort at high humidity", ASHRAE Transactions, 105(2), pp. 94-103; see ASHRAE Standard 55 (2013) Thermal Environmental Conditions for human occupancy, Atlanta, USA).

[0040] The control algorithm may utilize historical weather data to calculate dynamic setpoints for natural ventilation, and may use analytical equations, which may be linear, to calculate optimal locations for passive ventilation devices based on outdoor and indoor air temperatures, as well as pressure differentials between inside and outside, particularly as reflected in buoyancy and / or wind-driven airflow. It may also include predictive data for a range of optional parameters, such as weather, occupancy, and preferred temperature settings, to allow for improved specificity in the proper configuration and control of passive ventilation devices.

[0041] The control method can be implemented in any existing building management system. In addition to sensors providing information about the status and possibly the mode of operation of each passive ventilation device, e.g., whether the building is cooled by passive natural ventilation mode or active mechanical mode, sensors of outdoor and indoor environmental conditions can and should also be used to provide the necessary inputs to the controller of the passive ventilation system. When mechanical mode is activated, the controller of the passive ventilation system is in passive / paused state and may let the established system control the heating and / or cooling.

[0042] Another aspect relates to a passive ventilation system comprising a control device configured to perform the method or any embodiment described above. A further aspect relates to a building comprising such a passive ventilation system.

[0043] The advantages and advantageous embodiments of the passive ventilation system and building correspond to the advantages and advantageous embodiments of the described method.

[0044] The features and combinations of features described above, including the general part of the description, and features and combinations of features disclosed in the description of the drawings or only in the drawings, may be used alone or in the combinations described, as well as with other features or without some of the disclosed features, without departing from the scope of the present invention. Consequently, embodiments not explicitly shown and described by the drawings, but which may be created by individually combining individual features disclosed in the drawings, are also part of this disclosure. Thus, embodiments and combinations of features that do not include all features of the independent claims originally formulated shall be considered disclosed. Furthermore, embodiments and combinations of features that differ from or deviate from the combinations of features described by the dependent relationships of the claims shall be considered disclosed.

[0045] Exemplary embodiments are further explained below by means of schematic diagrams, in which Figure 1 shows an exemplary flow chart of one embodiment of a method for controlling a passive ventilation system of a building. [Brief explanation of the drawings]

[0046] [Figure 1] 1 shows an exemplary flow chart of an embodiment of a method for controlling a passive ventilation system of a building.

[0047] In this embodiment, the indoor air temperature T 1 , which may be an average temperature, is determined as follows: int and the outdoor air temperature T, which may be the averaged temperature out Both are set at the heating set point T LL,HSP This is achieved by checking whether the indoor air temperature T is higher than the temperature T (in this case, plus some preset dead band temperature DB). intand outdoor air temperature T out Both are at the heating set point T LL,HSP If the indoor air temperature is not higher than the dead band temperature DB (plus the dead band temperature DB), i.e., if the indoor air temperature is low and heating is required, then in step S11 the indoor air temperature is set to the heating set point T LL,HSP It is checked whether the indoor air temperature is lower than the heating set point T LL,HSP If the temperature is lower than the dead band temperature DB, the window is closed and conventional mechanical heating is switched on in step S12. If the result of step S11 is "no", the window is closed in step Sx and heating / cooling is not switched on.

[0048] If the result of step S1 is "yes", i.e., mechanical heating is not required, then in step S2, the indoor air temperature T int and the outside air temperature T out Both are at the cooling set point T UL,CSP If the result of step S2 is "no", that is, if cooling is possibly required, the indoor air temperature T int is the cooling set point T UL,CSP It is checked whether the temperature T exceeds the dead band temperature DB. int is the cooling set point T UL,CSP If the temperature does not exceed the dead band temperature DB, the process proceeds to step Sx. int is the cooling set point T UL,CSP If the temperature exceeds the dead band temperature DB (plus the dead band temperature DB), the window is closed in step S22 and conventional mechanical cooling is started.

[0049] If the result of step S2 is "yes", i.e., mechanical cooling is not required, then in step S3 it is checked whether a passive ventilation device, such as a window, is open. If the result of step S3 is "yes", the passive ventilation device or devices are kept in their current state in this embodiment in step Sy, and the process starts again.

[0050] If the result of step S3 is "no," then in step S4, the state of at least one passive ventilation device of the passive ventilation system is controlled via setting a percentage open value OF, where the percentage open value OF varies between 0 and 1 and corresponds to a respective state of a corresponding passive ventilation device of at least one zone in the ventilated building. The state can be either a closed state, an open state, or one of one or more intermediate states between the closed and open states. A percentage open value of 0 corresponds to the closed state, a percentage open value of 1 corresponds to the open state, and an opening percentage value between 0 and 1 is associated with one or more intermediate states.

[0051] Calculated temperature difference ΔT=T int -T out is less than or equal to a preset lower limit temperature difference k, the opening percentage value is set to 1. If the calculated temperature difference ΔT is greater than or equal to a preset upper limit temperature difference m, the opening percentage value is set to a lower limit percentage l that is greater than or equal to 0 and less than 1, in this example, greater than 0. In all other cases, that is, if the calculated temperature difference is less than the preset upper limit temperature difference m and greater than the preset lower limit temperature difference k, the opening percentage value is the value of the passive ventilation function of the calculated temperature difference ΔT. This passive ventilation function monotonically decreases as the calculated temperature difference ΔT increases, and in this embodiment is a linear function f(ΔT) = (ΔT - m) / (km).

[0052] The presented control strategy achieves energy-efficient and thermally comfortable building ventilation.

Claims

1. 1. A method for controlling a passive ventilation system of a building, comprising: - the outdoor air temperature around the building (T ｏｕｔ ) measuring the - the indoor air temperature (T ｉｎｔ ) measuring the - the outdoor air temperature (T ｏｕｔ ) is calculated by dividing the measured value of the indoor air temperature (T ｉｎｔ calculating a temperature difference (ΔT) by subtracting the temperature difference (ΔT) from the temperature measurement; - if the calculated temperature difference (ΔT) is greater than 0, controlling the state of at least one passive ventilation device of the passive ventilation system to be in one of the following states: closed, open, or one or more intermediate states between closed and open, each of said states corresponds to a value of an Opening Fraction (OF) of said at least one zone within said building, said Opening Fraction (OF) ranging between 0 and 1; 0 corresponds to the closed state, 1 corresponds to the open state, a controlling step, wherein each passive ventilation device is configured for fluid communication between a respective at least one of the at least one zone in the building and an ambient environment of the building; The state of the at least one passive ventilation device is controlled via setting the open fraction value (OF), the open fraction value (OF) being: If the calculated temperature difference (ΔT) is less than or equal to a preset lower temperature difference limit (k), then an upper percentage equal to 1, - If the calculated temperature difference (ΔT) is equal to or greater than a preset upper limit temperature difference (m), a lower limit ratio (l) is set to a value greater than or equal to 0 and less than 1. otherwise, a passive ventilation function value for said calculated temperature difference (ΔT), said passive ventilation function being set to a passive ventilation function value that monotonically decreases with increasing calculated temperature difference (ΔT); determining, according to a prediction, whether the outdoor air temperature (T out ) of the air in the surrounding environment of the building will exceed an upper outdoor temperature limit within a predetermined elapsed time; If the outdoor air temperature (T out ) is greater than the upper outdoor temperature limit, the state of the at least one passive ventilation device is set to a state corresponding to an opening percentage value (OF) that is higher than that of the state of the at least one passive ventilation device corresponding to the outdoor air temperature measured for the current time, or lower than that of the state of the at least one passive ventilation device corresponding to the outdoor air temperature measured for the current time.

2. The state of the at least one passive ventilation device is determined by the outdoor air temperature (T ｏｕｔ ) and the measured indoor air temperature (T ｉｎｔ ) measurements are taken at the lower set point, i.e., the heating set point (T ＬＬ，ＨＳＰ ) and the upper or cooling set point (T ＵＬ，ＣＳＰ ) and is set to a closed state otherwise, and in particular, the heating set point and the cooling set point (T ＬＬ，ＨＳＰ , T ＵＬ，ＣＳＰ 2. The method of claim 1, wherein the temperature can be set as a dynamic setpoint according to a formula depending on a comfort temperature, and the comfort temperature can be set according to another formula depending on a moving average outside temperature, such as a 7-day moving average outside temperature.

3. 3. The method of claim 1 or 2, wherein the state of at least one of a window, a damper, and a vent is controlled as the state of the at least one passive ventilation device.

4. 4. The method according to claim 1, wherein it is determined whether the at least one zone is occupied and / or is to be occupied at a given time in the future, and the state of the at least one passive ventilation device is controlled via setting the open fraction value (OF) only if the respective zone is occupied and / or is to be occupied at a given time within a preset elapsed time, and is set to a closed state otherwise.

5. 5. The method of claim 1, wherein the lower limit percentage (l) is set to a value greater than 0 if a predetermined criterion is met, and is set to 0 if the criterion is not met, the criterion including that the at least one zone is occupied.

6. The method according to any one of claims 1 to 5, wherein the passive ventilation function is a linear function of the calculated temperature difference (ΔT).

7. 7. The method of claim 6, wherein the linear function is proportional to [ΔT−m], where ΔT is the calculated temperature difference (ΔT), m is an upper temperature difference limit (m), and is proportional to or equal to [ΔT−m] / [k−m], where k is a lower temperature difference limit (k).

8. The passive ventilation function is {1 / sqrt[a1 ＊ ΔT]} or {1 / sqrt[a0 + a1 ＊ 8. The method of claim 1, wherein the passive ventilation function is a function proportional to {ΔT}, a0 and a1 are variables, and the passive ventilation function is limited to a maximum value of 1 or equivalent.

9. The variables a0 and a1 are the desired total airflow m through the at least one passive ventilation device. ｔ (m ｔ ) and in particular the total air flow m ｔ is m ｔ ２ = m ｂ ２ +m ｗ ２ is given by m ｂ is the air flow rate due to buoyancy (m ｂ ) and m ｗ is the air flow rate due to wind (m ｗ 9. The method of claim 8, wherein

10. The passive ventilation function is [Q ｇ / {C Ｐ ＊ [T ｉｎｔ -T ＵＬ，ＣＳＰ ] ＊ sqrt[0.05 ２＊ V ｒ ２ +C ｄ ２＊ {[2 ＊ ΔT ＊ h ＊ g] / [T ａｖ +273℃]}]} / A ｍ ], and Q ｇ is the preset total heat gain, C Ｐ is the specific heat capacity of air, T ｉｎｔ is the measured value of the indoor temperature, T ＵＬ，ＣＳＰ is the cooling set point, V ｒ is the wind speed in the surrounding environment of the building, C ｄ is a preset emission factor, h is the predetermined vertical distance between the centers of the openings of different passive ventilation devices; g is the acceleration due to gravity; T ａｖ is the indoor air temperature and the outdoor air temperature (T ｉｎｔ , T ｏｕｔ ) is the average value of the measured values ​​of A ｍ is the preset maximum openable geometric area of ​​the at least one passive ventilation device of the passive ventilation system.

11. The wind speed V ｒ is measured by a wind sensor in the passive ventilation system, and / or the total heat gain Q ｇ is set or calculated depending on whether the at least one zone is occupied and / or whether it is to be occupied at a given time in the future, in particular by how many people.

12. A passive ventilation system comprising a control device configured to perform the method according to any one of claims 1 to 11.

13. A building equipped with a passive ventilation system according to claim 12.

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