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In this article we compare to ventilation strategies to heat a “passive house” office building using only the ventilation system. Two ventilation strategies with supply air temperature above and below the current room temperature were compared through a cross over experiment. A questionnaire was used to measure the perceived health and well being. Both strategies documented very good indoor climate with highly positive scores on the questionnaire.

Increasing airtightness and isolation of residential buildings in today’s climates cause challenging situations for the summer indoor climate. In combination with ventilation for fresh air, it calls for intelligent control of passive cooling when available, and active cooling when needed.

The combination of heat recovery ventilation and an air-to-air heat pump cooling system is a solution to these challenging situations. With the exhaust air heat pump cooling system, heat is transferred from the supply air (which is getting colder) to the exhaust air (which is getting warmer).

Is Demand-controlled ventilation a relevant answer to face the new challenges of the Building sector, which requires everyday higher energy efficiency and better indoor air quality? Can Demand-controlled ventilation be considered as an alternative to heat recovery ventilation, through an affordable and low maintenance solution? Since the take off of the DCV in the early 80’s, these questions have been considered many times.

The “VIA-Qualité” project (2013-2016) focuses on low energy, single-family dwellings. It proposes the development of quality management approaches (ISO 9001) which aim to increase both on-site ventilation and indoor air quality. One of the main benefits of those approaches is the improvement of ventilation system performance, especially thanks to a rigorous follow-up from design to installation. Efficient ventilation system performance is rewarded in the French EP-calculation, through a primary energy consumption estimation.

For the coming energy-efficient buildings, the guarantee of energy performance becomes a major challenge. It is therefore crucial to implement accurate and reliable measurements, in order to ensure this performance. The in-force French EP-regulation RT2012 already imposes compulsory justification of envelope airtightness. Moreover, the Effinergie+ label requires ventilation systems control and ductwork airleakage performance. These requirements, ventilation controls for IAQ concern and regulatory compulsory controls of buildings need reliable diagnostic protocols.

The effect of a cooling jet from ceiling on thermal comfort, perception and subjective performance in warm office environment (29.5 °C) was studied. Altogether, 29 participants (13 male and 16 female) participated. All participants were tested in both thermal conditions and the order of the thermal conditions was counterbalanced between the participants. During the experiment, participants filled questionnaires and performed computerised tasks. Using the cooling jet significantly improved the whole body and local thermal comfort.

Central ventilation systems with heat recovery have shown their limits especially within the context of building energy retrofit. The difficulties to install these systems in existing buildings, to find available space for devices, air ducts, silencers and fire dampers and to independently control the air flow in each room according to the real ventilation needs have led to an increasing market for decentralized ventilation devices.

The indoor climate in residential buildings is affected by the people that live in the house and their activities. One of the goals of a ventilation system is to prevent excess humidity in the house by removing part of the moisture. The moisture balance can however be distorted in winter with a low humidity in the house as a result.

Measurements were performed in a test room at SINTEF building and infrastructure, Oslo. The test room is 16 m2 and built according to NS-EN 442-2.  Measurements of various air flow rates (9 l/s, 18 l/s, 34 l/s and 50 l/s) and different supply air temperatures (2, 4, 6 and 10 degrees over room temperature) were performed. Tracer gas (SF6) measurements were performed to evaluate ventilation effectiveness and age of air in occupied zone.

An office building of the Fraunhofer Institute for Solar Energy systems (Fraunhofer ISE) in Freiburg was retrofitted in 2012 with an innovative concept based on technology integration in the façade. Prefabricated window modules integrating air inlets and outlets, façade integrated air ducts and a heat and moisture recovery ventilation device were implemented. A long term monitoring was set up including energy, temperature, CO2 and humidity measurements.