English

HVAC systems in newly built or extensively renovated dwellings were all developed with the aim for energy saving with equal or better comfort. However, these systems (floor heating and DCV systems) have certain characteristics which increase the emissions of Volatile Organic Compounds (VOCs) and give VOCs the chance to accumulate to higher concentrations. This interaction is investigated based on dynamic simulations using a temperature and humidity dependent VOC emission model. 

Duct routing often poses a great challenge when planning the installation of a mechanical ventilation system with heat recovery. This is particularly true for retrofits, where the necessary space for supply and exhaust ducts was originally not accounted for. This extended summary presents an alternative approach for duct routing avoiding ducts in the dwelling, while allowing the installation of a centralized MVHR unit and the implementation of a cascading airflow through the dwelling.

Humidity-based DCV systems have been widely used in France for 35 years and are considered as a reference system, including for low-energy residential buildings. Indeed, most of the new residential buildings, which must be low-energy buildings to comply with the RT 2012 energy performance regulation, are equipped with such systems. Feedbacks from two long-term studies show the durability of the humidity sensitive components and show the robustness of this system to bad maintenance or use by occupants.

The present paper aims at illustrating the practical use of the Annex68 IAQ Dashboard. To this end, numerical simulations have been performed to provide useable data about the Indoor Air Quality (IAQ) of a low-energy detached house. The dashboard has been used to compare three possible solutions of ventilation systems commonly found in French residential buildings i.e. natural ventilation using vertical ducts for extraction, self-regulated exhaust and balanced mechanical ventilation.

This presentation will cover the key lessons learned from post-occupancy evaluation of the ventilation strategies in several new-build dwellings in the UK. Two ventilation strategies often used for new dwellings in the UK are mechanical extract ventilation (MEV) and whole-house balanced mechanical ventilation with heat recovery (MVHR). Few examples of the design and operation of these systems will be presented identifying the best practice and improvement opportunities for mechanical ventilation systems that are increasingly used in airtight low-energy dwellings. 

This report reviews the activities of the AIVC during its first twenty years of operation. It identifies key projects and addresses them in the context of research activities and associated issues of the time. Early issues included the need for energy conservation and reducing air infiltration loss. Much work concentrated on assessing the performance of numerical models and acquiring input and validation measurement data. Towards the end of the period attention focused towards energy efficient ventilation systems for good indoor air quality and comfort.

The modelling of air flows to investigate indoor air quality and energy issues has been a topic at the AIVC for all of its 40 years. Models have been developed that range in complexity from single-zone algebraic expressions that can be calculated by hand to complex multi-zone approaches that integrate contaminant transport and other functions.

The purpose of this summary is to review Air Infiltration and Ventilation Centre activities, as reflected in its publications, related to indoor carbon dioxide over the 40 years that have transpired since its creation. These activities, like most applications of indoor CO2 to the fields of ventilation and indoor air quality, have focused on the following: control of outdoor ventilation rates, i.e., demand control ventilation; use as a tracer gas to measure outdoor air change rates; providing an indicator or metric of IAQ; and, directly impacting human health, comfort and performance.

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.

Japan is characterized by high humidity in summer and low humidity in winter. Therefore, summer is in a climatic condition where mold is easy to grow, and in fact, mold damage is occurring. Due to improvement of the thermal insulation and airtightness of houses, the temperature in the room is maintained high even in winter, and mold damage occurs. We will introduce the research we have conducted regarding humidity environment and health problems, and discuss future subjects. The outline is as follows.