Rethinking Occupancy-Based Ventilation Controls

Traditionally, occupancy-based ventilation controls have only ventilated when occupants are present – usually based on measurements of CO2 and/or humidity.  These indictors may be fine for pollutants released directly by occupants, such as bioeffluents, or by their activities, such as cooking and cleaning. However, they do not account for pollutants not associated with occupancy, such as formaldehyde from building materials and furnishings.

A review of performance-based approaches to residential smart ventilation

In order to better address energy and indoor air quality issues, ventilation needs to become smarter. A key smart ventilation concept is to use controls to ventilate more at times it provides either an energy or IAQ advantage (or both) and less when it provides a disadvantage. This would be done in a manner that provides improved home energy and IAQ performance, relative to a “dumb” base case. This paper highlights that a favourable context exists in many countries, with regulations and standards proposing “performance-based approaches”.

Ventilation tool for improving the usability of ventilation levels related to Spanish regulations

Choosing the right baseline level of ventilation has a big impact in the calculated energy needs of buildings.

Numerical evaluation of the impact of hemp lime concrete moisture-buffering capacity on the behaviour of relative humidity sensitive ventilation system

Hemp Lime concrete (HLC) is a bio-based material, which knows currently a growing development. HLC is a low embodied energy material. It has an excellent moisture buffer performance and is considered as good indoor climate regulators. Recent field study has confirmed the ability of HLC to maintain hygrothermal conditions at winter and summer comfort levels.  

Experimental characterization of the efficiency and energy consumption of various central ventilation air cleaning systems

The present study aimed at assessing six commercially-available in-duct air cleaning devices which are designed to be mounted in the central ventilation system of offices or commercial buildings. The selected devices use different air cleaning technologies: mechanical filtration, electrostatic precipitation, gas filtration, ionisation / cold plasma, photocatalytic oxidation (PCO) and catalysis under UV light.

Performance Testing of a Residential Motorless Air Exchanger System

A heat recovery ventilator (HRV) is used to create a balanced ventilation system in residential buildings and as an energy-saving measure. HRVs bring in outside air which is tempered with outgoing stale air, with only the small energy penalty of the blower power to overcome the pressure drop in the HRV. HRVs have been used in cold climates and have often performed poorly due to frosting failure.

Measured moisture buffering and latent heat capacities in CLT test houses

This research investigates the significance of the moisture buffering and latent heat capacities in exposed cross-laminated timber (CLT) walls with the respect to indoor climate and energy consumption. Hygroscopic materials have the ability to accumulate and release moisture due to change in the surrounding humidity. The moisture buffer capacity is regarded as this ability to moderate, or buffer, the indoor humidity variations. Latent heat refers to the heat of sorption due to the phase change from vapour to bound water in the material and the other way around.

Demand controlled ventilation in renovated buildings with reuse of existing ductwork

Most existing non-residential buildings have Constant Air Volume (CAV) ventilation leading to over-ventilation in periods with low or no occupancy. Demand controlled ventilation (DCV) can considerably reduce the ventilation airflow rate and energy use for fans, heating and cooling compared to constant air volume (CAV) ventilation. There is a potentially enormous upcoming marked for converting from CAV to efficient DCV in existing commercial buildings.

Thermal efficiency of the window shade

The purpose of this paper is to find the efficiency of window shades regarding building energy performance and explore the possibility of developing a model that enables users to find proper shades for their specific conditions. The paper investigates different options of shades and their related variables and finds the efficiency of the shades regarding energy load. Each variable was investigated for its effect on the heat loads. Results were used as input variables for neural network prediction model.  A prediction model was developed and trained based on the previous simulation results.