Evaluation of different thermal models in EnergyPlus for calculating moisture effects on building energy consumption in different climate conditions

Building energy simulation is essential for most architectural design projects. Many models have been developed to predict the indoor air temperature and relative humidity as well as the building’s heating and cooling loads. However, in most building energy analysis the calculation of heat conduction through walls usually neglects the transport and storage of moisture in porous building materials, and the interaction between hygrothermal transfer and airflow inside the building.

Models for residential indoor pollution loads due to material emissions under dynamic temperature and humidity conditions

The IEA EBC Annex 68 project on “Indoor Air Quality Design and Control in Low Energy Residential Buildings” has been recently completed. The project considered indoor air pollution loads in dwellings, particularly how such pollutants are emitted in dependency of the hygrothermal conditions: temperature, moisture and air flows. Thus, a proper understanding of the mutual interactions between hygrothermal conditions and pollutants was needed to obtain optimal paradigms for demand-controlled ventilation.

Moisture in indoor air: findings of 40 years

This extended summary is a part of a more extensive summary (technote to be published) that compiles a number of AIVC publications that deal with ventilation and health in relation to moisture in air, and the development over time.

Big humidity data from smart ventilation systems

A smart ventilation system is generally equipped with a range of sensors. The data – or data derived from it - collected by these sensors can be used by both building owners, occupants and managers. A new generation of IoT  enabled residential ventilation systems allows collecting and analysing this data at scale to get a better view on typical IAQ conditions in dwellings. In this paper, the results from such an analysis on the first 900 installed devices of a new model with respect to moisture in relatively new Belgian dwellings is presented. 

Detailed numerical modelling of moist air flow through a complex airtightness defect

Mastering building airtightness is essential to meet the requirements of current and future building codes, not only for saving energy but also for ensuring moisture safety. Perfect airtightness is difficult to achieve: failures are often observed, due to bad design or poor workmanship. Some published investigations proved that leaking air mostly flows through porous material and thin air channels, due to material imperfections and construction tolerances.

Carbon Dioxide Concentrations and Humidity Levels Measured in Belgian Standard and Low Energy Dwellings with Common Ventilation Strategies

One of the most commonly used strategies to reduce the heating demand in low energy buildings is reducing the leakage level of the building envelope. Dedicated ventilation systems are then installed to compensate for the reduced air change rate in an energy efficient way. Most occupants, however, operate their ventilation system at very low flow rates. Together with the emission of bio-effluents, linked to the presence of the occupants, moisture production related to household activities is one of the most important sources of indoor air pollution in dwellings.

The powerdomus environment for simulating HVAC systems

In this paper, the new capabilities of PowerDomus to simulate central HVAC systems combined to its whole-building hygrothermal model is presented. First, models for the primary (chiller, cooling tower, primary pumps and condensation pumps) and secondary (cooling and dehumidifying coil, humidifier, fan and mixing box) systems are presented. Those mathematical models have been integrated into the whole-building PowerDomus program.

Moisture and Condensation in Residential Buildings in a Relatively Dry Region

It is not unusual to face moisture problems in buildings in cold climates and wet regions. It is, however, unusual to have the same problem in a relatively dry region such as Jordon, which has moderate weather conditions and mild winters. Nevertheless, a significant proportion of houses and residential apartments in Jordan are affected. The monitoring of inside air conditions, wall surface temperatures, ventilation and living style has shown that a high relative humidity (RH >75%) occurs at walls resulting in possible condensation.