By Roland Graf
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The program was developed with the OS 5.1 and tested with iPhone and iPad.
Measuring instrument for temperature and humidity
Note a measuring instrument is necessary for the use of this program. The instrument should measure the temperature and the humidity in and outside of the building. Ideal is a device connected via a wireless outdoor sensor, which is itself protected from the rain in the shadow.
The program calculates the absolute humidity from the relative humidity within the temperature range from 14 to 95 °F (-10 to 35 °C). That should cover the needs of the most users. When entering a value outside of thid rsnge it is displayed.
The program calculates approximately the expected effect of dehumidification or humidification. This program always stores the last parameters with date and time. So you can switch to other applications without problems. The program calculates in degrees celsius (german) and in degrees fahrenheit (english).
Since version 2.0 this program calculates the dew point for inside and outside. At this temperature condensation occurs. The values are interpolated and may therefore differ about ± 0.2°F. The accuracy of the equipment does not allow a calculation with two decimal places. It is recommended to round up to integer temperature. Then you'll be on the safe side. It is recommended to perform painting works at least three (°C) or six (°F) degrees above the dew point.
Main application: historic building, churches etc.
The program has been used successfully during three years in summer and winter. The approach recommended here for clever ventilating has been very successfully in churches with thick walls and historic buildings. The room temperature in such buldings is relatively stable.The calculated theoretical dehumidification can be achieved to some degree.
Wooded houses have, however, a different pattern. They adapt to the ambient temperature much faster. Here it is important to make observations and experiences with the help of this program. Each bulding has its own characteristics and can store moisture and release it again depending on the furniture, the floors and the ceilings. Because of that, after ventilating the humidity may increase again.
Some useful notes
In case of large temperature difference in winter you should only ventilate briefly for energy-saving reasons. During the winter the humidity inside is rather low, it is rather to high in the summer. It should be in the range of 50 to maximum 70% relative humidity. It is not always possible to keep the humidity in the desired range. In well-heated rooms in winter the relative humidity is often lower than 50%. So you should work with a humidifier. Conversely, it is necessary for longer periods of rain in the summer to use a dehumidifier, not to get over 70% relative humidity. If you ventilate clever, you often reach in large buildings with 30 minutes intensive ventilating a greater effect than by hours of operation with a dehumidifier!
With and above 70% humidity you can get moldy. Most harmful are those situations in which warm air causes condensation on cold walls. This is the case when the temperature of the wall is at or below the dew point temperature. The program informs you about some hazards.
What's New in Version 2.1
For english users the calculation is now also in °C possible. Some Bugs fixed.
Unique, clever app
If you want to ventilate your home or business to reduce humidity using outside air, this is the app. This app turns some complex calculations into a simple task. All you need to know is the temperature and humidity inside and outside. One improvement would be to have the user's choice of units (e.g, Centagrade/ Fahrenheit) stick once set by the user.