WO2008039149A1

WO2008039149A1 - Device to protect a space from damage caused by damp or moisture

Info

Publication number: WO2008039149A1
Application number: PCT/SE2007/050686
Authority: WO
Inventors: Rikard Bergsten
Original assignee: Lindenstone Innovation Ab
Priority date: 2006-09-29
Filing date: 2007-09-28
Publication date: 2008-04-03
Also published as: SE0602058L

Abstract

The invention relates to a device to protect spaces from damage caused by damp or moisture, i.e., moisture-related damage, based on controlled heating or controlled heating in combination with controlled ventilation. The heating is controlled on the basis of a comparison of the climate in the space - temperature, air humidity and how these vary over time - and the risk of moisture-related damage in the current climate; if it is necessary to prevent moisture-related damage, the space is heated. The ventilation is controlled on the basis of a comparison of the climate in the supply-air space and in the protected space, so that if the vapour concentration is lower in the supply-air space, the space is ventilated and otherwise not.

Description

DEVICE TO PROTECT A SPACE FROM DAMAGE CAUSED BY DAMP OR MOISTURE

The present invention relates to a method and a device to protect a building space from damage caused by damp or moisture, i.e., moisture-related damage.

Moisture-related damage depending on too a high relative humid- ity is today usually occurring in heated as well as unheated spaces. Usual types of moisture-related damage comprise mildew and rot fungus attacks, nasty-smelling bacteria, deformed material or materials losing strength. Moisture-related damage occurs in new as well as in older buildings. The emergence of a moisture-related damage depends on a time aspect as well as on sufficiently high relative humidity and often temperature. In order for swelling damage to arise, the relative humidity has to have been high for the time needed for capillary condensation into the material to occur, most often several weeks. For mildew and damage caused by putrefaction should arise, it is not only required that the air humidity is favourable but also that the temperature is the same, and that the air humidity as well as the temperature have been favourable during the entire growing process, which normally goes on for days to months de- pending on the climate. At moderate temperatures between approx. +5 ⁰C and above room temperature, the risk of mildew fouling is the governing parameter that, based on a given tem^¬ perature and the climate history, indicates the highest allow^¬ able relative humidity. At lower temperatures, either rot fungi or deformation may be decisive for the highest allowable rela^¬ tive humidity. Below, there are shown two examples of scien^¬ tific literature having studied the ability of noxious fungi to grow depending on time, temperature and relative humidity.

Illustration from Vntanen, 2001, which describes the risk of mildew at different relative humidity levels, temperatures and time horizons, on wood material.

(RH%)

Temperatur (⁰C)

2 veckor 12 veckor 4 veckor 16 veckor 8 veckor 24 veckor Illustration from Lehtmen, Harderup, 1997, which describes the risk of mildew fouling at different relative humidity levels, temperatures and time intervals, on building materials found in the Nordic countries. Existing methods to protect spaces from moisture-related damage have either high energy consumption or weak effect at low temperatures. So-called sorption dehumidifiers lose a great part of the capacity thereof at low temperatures, condensation dehu- midifiers lose the greater part of the capacity thereof already at moderately low temperatures, and a heating system controlled only by the relative humidity - which has existed - may involve very high energy consumption. Furthermore, the heating systems have the shortcoming that it is difficult to properly adjust the passive ventilation. All other methods found on the market today only control based on the relative humidity, without considering the time aspect or the temperature.

In many spaces, and that is particularly true for roof spaces, the changes of temperature are great and hygroscopic materials store and empty themselves of moisture as the temperature and air humidity change. Current dehumidification systems utilize these natural changes poorly.

By the present invention, a device has came about that by controlling the supply of heat - or another dehumidification method - inside the protected space, based on known information about growing time and growing conditions for occurring mildew and rot fungi and absorption of moisture in occurring materials, secures a climate where moisture-related damage cannot arise, having low energy consumption. The device may also be combined with controlled ventilation so that the space is ventilated when the vapour concentration indoors is higher than outdoors. The ventilation can also be activated when the temperature in the space is affected in an unfavourable direction in respect of growth of mildew fungi, rot fungi and bacteria. Thus, the ventilation dries out the space and/or alters the temperature in an unfavourable direction.

The supplied heat lowers the relative humidity in the space and thereby decreases the amount of moisture supplied to the hygroscopic materials in the space; the heat also increases the capacity of the air to carry moisture and therefore enables a drying out of the hygroscopic materials in the space. Furthermore, the space may sealed so that no or only a little uncon- trolled ventilation is present. Furthermore, the space may be provided with non-return valves so that wind cannot urge venti^¬ lation on the system when it is undesired.

The invention is not limited to shown and described embodiments but may be varied in several ways within the scope of subsequent claims. Different trigger levels for the heating are of course feasible depending on occurring materials and fungi, as well as different ways to supplement and control, respectively, the ventilation for the space. Neither is it necessary for the function to seal the space or to provide it with non-return valves; said measures only contribute to decreasing the energy consumption where it is possible. It is also possible to achieve reasonably good results by combining the heating system with ventilation controlled only by the temperature difference between the space and the surroundings, so that it only ventilates when the temperature in the surroundings is lower or much lower than in the space (under the assumption that the amount of moisture in such a case most often is lower in the ambient air than in the space) . Furthermore, controlled ventilation in the combination with controlled heating may be replaced by or be supplemented with some other method for dehumidification, e.g., condensation dehumidification or sorption dehumidification. (Condensation dehumidification is carried out by a cool- ing radiator through which the air to be dehumidified is circulated, moisture condensing and being discharged or collected. Sorption dehumidification is carried out with a moisture absorbent that first is dried with hot air that is discharged, after which the air to be dehumidified is brought through the moisture absorbent) .

In the following paragraph, reference is made to Drawing 1.

By a sensor (J) , the control, measuring and regulating system (F) measures the temperature as well as the relative humidity or vapour concentration or moisture ratio in the space (A) and, by a sensor (I), the temperature and/or relative humidity or vapour concentration outside the space in (B) . If the vapour concentration in (B) is lower than in (A) , or if the vapour concentration is equal and the temperature in (B) is lower than in (A), the control system (F) activates the ventilation by a fan (C) and/or by a controlled valve (D) . The control system (F) activates a heating device (G) if the temperature and rela- tive humidity or moisture ratio in (A) are such, in the moment of measuring as well as earlier, that there may be risk of growth of mildew fungi, rot fungi or nasty-smelling bacteria or there is otherwise a risk of deformation or weakening of the material in (A) . A valve (H) allows throughput of air through the space. A possible non-return valve (E) blocks wind from forcing up an undesired ventilation of the space (A) through (H) .

Previously known Invention A

Since previously, a device is known to prevent moisture-related problems in a building space, characterized by a sensor outside the space that measures the temperature and relative humidity or vapour concentration, a sensor inside the space that measures the temperature and relative humidity or vapour concentra^¬ tion, and a controlled ventilation that is opened and/or forced when the air outside the space contains less moisture than the air in the space.

Claims

L122 P2PCT UH/ASLCLAIMS

1. Device to prevent moisture-related problems in a building space, characterized by a sensor placed in the space that measures the temperature and relative humidity or vapour concentration or moisture ratio and a heating assembly and a control system that activates the heating assembly only when, for occurring noxious fungi and building materi- als in the geographic region, there is risk of damage caused by damp or moisture, i.e., moisture-related damage in view of current and possibly historical temperature as well as current and possibly historical relative humidity, or indi^¬ cation, based on vapour concentration or moisture ratio, of current and possibly historical relative humidity and temperature, respectively.

2. Device according to claim 1, characterized in that a sensor that measures the temperature and relative hu- midity or vapour concentration is placed in the supply-air space and a fan placed between the supply-air space and the protected space and possibly one or more controlled valves between the protected space and the supply-air space, and a control system that maximizes the rotational speed of the fan and opens possible controlled valves when the vapour concentration of the supply air is lower than the vapour concentration in the space and otherwise turns off the fan and closes possible controlled valves.

3. Device according to claim 1, characterized in that a sensor is placed in the space that measures the tem^¬ perature and relative humidity or vapour concentration or moisture ratio and a control system that activates a dehu- midification assembly of sorption or condensation type that dehumidifies the air in the space when, for occurring noxious fungi and building materials, there is risk of moisture-related damage in view of current and possible histori- cal temperature as current and possibly historical relative humidity, or indication, based on vapour concentration or moisture ratio, of current and historical relative humidity and temperature, respectively.

4. Device according to claim 1, characterized in that an air dehumidifier of condensation type or sorption type is included in the system and is activated when there is risk of moisture-related damage in view of current and possibly historical temperature as well as current and pos- sibly historical relative humidity, or indication, based on vapour concentration or moisture ratio, of current and historical relative humidity and temperature, respectively, and when it is so warm that an air dehumidifier of condensation type or sorption type is more energy-efficient than heating with the heating assembly.