Method and device for controlling a controlled mechanical ventilation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Insulated walls in buildings are prone to condensation, leading to degradation of insulating materials and energy losses due to the permeability of water vapor, which existing technologies have not effectively addressed.
Innovation Solution
A method for controlled mechanical ventilation that monitors temperature and water vapor pressure across insulated walls, increasing ventilation speed when condensation is detected, and adjusting humidity and temperature setpoints to prevent condensation formation, using a control device that determines effective temperatures and vapor pressures at insulation junctions and adjusts the ventilation system and heating accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the building uses insulated walls with water vapor permeable materials, then thermal insulation performance is improved, but condensation forms in the wall core leading to material degradation
Solution Approach 1:
The control device performs preliminary calculations of temperature and water vapor pressure profiles through the wall layers before condensation occurs. By computing effective temperatures and saturated water vapor pressures at each layer interface in advance, the system can predict condensation risk and take preventive action by adjusting ventilation speed before actual condensation forms.
Solution Approach 2:
The system continuously monitors environmental conditions (indoor/outdoor temperature and humidity) and uses this feedback to dynamically adjust the mechanical ventilation speed. The control device compares calculated effective water vapor pressures with saturated water vapor pressures at wall junctions, and when condensation is detected or predicted, it increases ventilation to remove excess moisture from the building envelope.
2Reliability
If mechanical ventilation speed is increased to remove moisture, then condensation formation is reduced, but energy consumption increases
Solution Approach 1:
The mechanical ventilation speed is made dynamic rather than static. The control device continuously adjusts the ventilation speed based on real-time environmental conditions and calculated condensation risk. When condensation risk is low, ventilation operates at lower speeds to conserve energy; when condensation is detected or predicted, the system dynamically increases ventilation speed to prevent material degradation.
Solution Approach 2:
The system changes the operational parameters of the ventilation system based on calculated water vapor pressure and temperature profiles. By monitoring effective water vapor pressures at different wall layers and comparing them with saturated pressures, the system adjusts ventilation parameters (speed, flow rate) to maintain conditions that prevent condensation while minimizing energy consumption during low-risk periods.
3Loss of energy
If the building uses tight insulation layers, then thermal performance is improved, but water vapor diffusion resistance increases leading to condensation risk
Solution Approach 1:
The control device performs preliminary calculations of water vapor diffusion through each insulation layer by computing resistance to water vapor diffusion (RD) for each material layer. By calculating temperature and vapor pressure profiles across the wall assembly in advance, the system identifies junctions where condensation may occur and takes preventive action before moisture accumulates in the insulation.
Solution Approach 2:
The system uses feedback from environmental sensors and calculated vapor pressure profiles to monitor the actual water vapor conditions within the wall structure. When the calculated effective water vapor pressure approaches or exceeds the saturated water vapor pressure at any insulation junction, the system increases ventilation to reduce indoor humidity and prevent condensation in the tight insulation layers.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively limits or avoids condensation at insulation layers, preserving the integrity of insulating materials and reducing energy losses by dynamically managing ventilation and temperature settings based on real-time moisture and temperature data.
Implementation Method 1
determining, from information representative of the temperature measurements, effective temperatures at respective insulation junctions in said insulated wall
Implementation Method 2
determining, from the determined temperatures at the insulation junctions in said insulated wall, saturated water vapor pressures at the respective insulation junctions in said insulated wall
Implementation Method 3
determining, from the information representative of the water vapor pressure measurements, effective water vapor pressures at the respective insulation junctions in said insulated wall
Implementation Method 4
the control device increases the ventilation speed of the controlled mechanical ventilation when the comparison shows condensation forming
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A control device obtains (401) information representative of temperature and water vapor pressure measurements on either side of insulated walls of a building. For each insulated wall, the control device: determines (403), from the information representative of the temperature measurements, the effective temperatures at the respective insulation junctions; determines (404), from the determined temperatures, saturated water vapor pressures at the respective insulation junctions; determines (405), from the information representative of the water vapor pressure measurements, the effective water vapor pressures at the respective insulation junctions; and performs (406) a comparison of the respective effective and saturated water vapor pressures. The control device increases the ventilation speed when the comparison shows condensation forming at at least one insulation junction in at least one insulated wall.