Abstract: A macro-enabled workbook (in Norwegian) to aid balancing ventilation duct systems using the proportional method.

Abstract: MiniBalance is a tiny (hence its name) yet smart multilingual spreadsheet to assist balancing of air flows in mechanical ventilation systems, i.e. adjusting dampers and air terminal devices. It is a timesaving tool for HVAC/TABS contractors, using a smartphone, tablet or laptop. MiniBalance applies the accurate proportional method of balancing, in combination with other fluid dynamics theory.

Abstract: Macro-enabled workbook for processing monthly .dat files of minute-data downloaded from the Baseline Surface Radiation Network (BSRN). It conducts multiple quality-checks, fills gaps in data by interpolation, and calculates hour-averages.

Abstract: An Excel Workbook tool (in Norwegian) to accurately calculate pressure drop ventilation ductwork. Includes a small library of pressure loss coefficients (zeta-values) for duct fittings.

Abstract: Natural materials like wood absorb and release moisture, thus wood can buffer indoor climate. When used wisely, this buffer potential can be used to counteract the outer climate influence on the building. The mass of moisture used in the buffer is defined as the potential hygrothermal mass, which can be an energy storage in a building, equivalent to thermal mass. Hygrothermal mass works like a natural heat pump, where the moisture is active in damping the diurnal changes. In Norway, the ability of wood as a material used for climate buffering is tested in several buildings with extensive use of wood, including Supermarkets. \tThis paper defines the potential of hygrothermal mass in a Supermarket building. This includes the chosen ventilation strategy, and how the climate impact of the building is reduced. The ventilation control in Valnesfjord includes the weather forecast and historical data. That is, a five-day forecast and a two-day history. This is to prevent adjustments to smaller weather changes. The ventilation control has three zones. During summer, the moisture is retained to dampen for solar radiation through drying. In the winter time, moist air let into the shopping area to contribute to the heating. When letting the temperature down during the night the moisture absorbed in the wood slow down the cooling. The ventilation system is shut down during closing hours of the supermarket in this period. During the autumn and spring, a regime of either storing the moisture or drying out to according to the weather prognoses is defined. To ensure indoor climate quality, measurements of CO₂ and VOC overrule the low energy control if needed. For 2017 the presented ventilation control started in the end of September at the Supermarket in Valnesfjord. Six Supermarkets are compared to see if there are any measured differences in the energy consumption according to an improved degree-day method. The difference is not significant at this stage. However, there are some potential let to be exploited both regarding control and design in future projects. Future knowledge on hygrothermal mass potential in materials is promising. When including the time dependent buffer capacity of materials, building operators can achieve optimal efficiency of their ventilation systems. The use of wood as a climate regulating material, through its potential hygrothermal mass and connected to weather prognoses, may provide up to 25 % energy savings related to heating, cooling and ventilation of a building.

Abstract: Use of Demand Controlled ventilation (DCV) can potentially save more than 50% of energy use for ventilation purposes compared to constant air volume (CAV) ventilation. Correct and updated calculation of preset minimum (Vmin) and maximum (Vmax) airflow rates are important to maximize energy saving and to ensure good indoor quality. Furthermore, earlier studies have shown that controlling units’ ability to actually handle V min is lacking and causes instability in the DCV systems. State of the art study of leading Norwegian consulting firms documented that use of advanced Spreadsheet-sheets is the common approach for calculation ventilation rates, where the main focus is on Vmax. This even if use of BIM (Building Information Modeling) is common in this kind of firms. Based on this knowledge, we have developed a BIM-integrated Design tool for calculation of ventilation rates. This tool defines a method for using specific data for each space within the model as basis for the calculations. By running different scripts, recommended ventilation rates are easily calculated. The tool can save hours of work and ensure correct values in line with changes done during the design phase. The tool has a built-in check of the VAV-dampers ability to control air flow rates from Vmix to Vmax. This will increase the focus on Vmin, and implemented recommendations are new research-based values. The tool also includes first recommendations on ventilation rates based on CO₂ calculations. These calculations will be further developed.

Abstract: Demand-Controlled Ventilation (DCV) are often underperforming regarding energy saving potential and indoor climate. This is caused by reasons like design, components, specifications, handover documentation, or communication errors. We developed guidelines and commissioning procedure to improve the performance of DCV-systems in 2013. In this paper we present the first experiences from a cost and time-efficient spot checking procedure for functional control of DCV-systems. The purpose of the procedure is to reveal if the systems have any hidden shortcomings, errors or defects after the hand-over procedure is accomplished. The control procedure was taken into use summer 2016 and has so far been performed in 22 school buildings in Oslo. 11 schools passed the control. The main experience is that DCV-systems can roughly be divided into two groups, “well-functioning VAV” and “malfunctioning VAV”. Well-functioning VAV seems to be designed and assembled with a top-down awareness on competence and quality. They are close to faultless and well fitted for the operation phase. Malfunctioning VAV might have almost countless errors or defects, easy to reveal in a simplified control procedure. We also see that the newest schools have an overall better VAV-performance, indicating that the control procedure has increased the DCV quality.

Abstract: The aim of our study is to investigate whether it is necessary to adjust the ventilation requirements according to different user groups. This study is focusing especially on teenagers, who might have a higher odour load than children due to increased hormone and sweat production during puberty. The odour intensity (OI) and the perceived air quality (PAQ) were evaluated in four classrooms in Oslo, Norway. Two control classrooms of 9–11 years olds (children) were compared with two case classrooms of 12–15 years olds (teenagers). A sensory panel of 18 untrained people visited the four classrooms three times during a three-hour period and were asked to evaluate PAQ and OI upon entering the classrooms. The classrooms were supplied with a constant ventilation rate of 7 l/s per person, with no additional ventilation for building materials. We found that the classroom with children had a significant better PAQ-score than both classrooms with teenagers. Furthermore, although the ventilation rate per person was reduced, the percentage of panellists dissatisfied with OI and PAQ was lower (<20%) than expected. Our results indicate that children and teenagers have different sensory pollution loads, and therefore might need differentiated ventilation rates if the ventilation rates were to be optimised. However, more research is needed.
Permalink: https://doi.org/10.1007/978-3-030-00662-4_73

Abstract: To assess how people are influenced by relative humidity (RH) in cold climates, a study was conducted in an open office landscape in Oslo, Norway. The study took place during three cold days in February 2017. Fourteen subjects were blindly exposed to different levels of RH in the order of low (14 ± 1%), high (38 ± 3%), and medium (24 ± 4%). The subjects received emails twice a day (at 12:00 and at 14:30) with a link to a webpage where they were asked to: (1) assess perceived air quality (PAQ), (2) respond to a questionnaire about indoor environment quality and symptoms. The subjects performed normal office activity in between the two sessions. We found no significant impact of the level of RH on PAQ. Nevertheless, there were significantly more complaints about dry air at low RH than at medium and high RH. Furthermore, the air was perceived to be significantly more stuffy and heavier at high RH than at medium RH. There were no significant differences in thermal comfort at different RH, yet more people complained that it was cold on the day with low RH and warm on the day with high RH. Generally, there were few complaints related to symptoms at different RH. There were however significantly more complaints of itching and burning in the eyes at low RH than at medium and high RH.
Permalink: https://doi.org/10.1007/978-3-030-00662-4_76

Abstract: This study was conducted to assess how different filter types in the ventilation system affect the indoor NO₂ concentrations. Measurements were carried out in two classrooms and air intakes in a primary school located in Oslo, Norway. A regular F7 particle filter and an F7 combination filter with activated charcoal lining were compared. NO₂ concentrations were measured for five weeks during winter 2017 in a cross-over study design to compare: (1) NO₂-levels in classrooms with regular filter (RF) versus combination filter (CF); (2) indoor/outdoor ratio with regular filter versus combination filter. One-hour average concentrations are reported during operating time of the ventilation system (6:00–23:00) and during hours with high (>40 µg/m3) outdoor NO₂ concentrations. The measured average NO₂ concentrations in both classrooms with an RF were significantly higher than with a CF. The median CF/RF ratios for the two classrooms were 0.50 and 0.81 during hours with high NO₂ concentrations, and 0.48 and 1.00 during the period the ventilation system was operational. During hours with high NO₂ concentrations, the median indoor/outdoor ratios for the two classrooms with an RF were above 1.00, while the corresponding ratios with a CF were 0.78 and 0.75. Our results demonstrate that a combination filter is more efficient than a regular filter in reducing NO₂ concentrations in classrooms during hours with high outdoor concentrations.
Permalink: https://doi.org/10.1007/978-3-030-00662-4_77

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Abstract not available