Application of open-source CFD software to the indoor airflow simulation

The use of open-source CFD has been growing in both industry and academia. Open-source CFD saves users a considerable license cost and provides users with full transparency of implementation and maximum freedom of customization. However, it is often necessary to assess the performance of an open-source code before applying it to the practical use. This study applies one of the most popular open-source CFD codes – OpenFOAM to the indoor airflow and heat transfer prediction. The performance of OpenFOAM is evaluated and validated against a well-documented benchmark test.

Building and ductwork airtightness requirements in Europe – Comparison of 10 European countries

Mandatory building airtightness testing has come gradually into force in the UK, France, Ireland and Denmark. It is considered in many other European countries because of the increasing weight of the energy impact of building leakage on the overall energy performance of low-energy buildings.
This study analyses recent developments in 10 Europeans countries on the following aspects:
- requirements regarding building airtightness in EP- regulation
- requirements in specific energy programmes
- airtightness testers schemes

Microorganism contaminants removal in a liquid desiccant dehumidification system

The main focus of this research is to estimate the ability of a liquid desiccant (LD) system operation to remove microorganism particles. The dehumidification performance of the LD systems generated by using a lithium chloride (LiCl) solution as the liquid desiccant material. To verify the removal performance of microorganism particles, the experimental method was divided into cases where the process air passed or bypassed the LD unit.

Energy performance prediction of thermoelectric ceiling radiant panels with a dedicated outdoor air system

This paper proposes a dedicated outdoor air system (DOAS) with thermoelectric module radiant cooling panels (TEM-RCP). The DOAS involves the concept of a decoupled system with a parallel sensible cooling unit. This concept implies decoupling of ventilation and air-conditioning functions. The DOAS treats latent loads from outside air intake as a 100 % OA ventilation system. Additionally, a parallel sensible cooling unit, such as ceiling radiant cooling panel (CRCP), generally removes sensible loads.

Evaluation of thermal comfort in an office building served by a liquid desiccant-assisted evaporative cooling air conditioning system

Recent studies examined a liquid desiccant indirect and direct evaporative cooling assisted 100% outdoor air system (LD-IDECOAS) as an energy conserving alternative to conventional air conditioning systems. An IDECOAS was introduced as an environmental-friendly air conditioning system that uses latent heat of water evaporation to cool the process air. Recently, studies suggested the integration of a liquid desiccant(LD) system with an IDECOAS to overcome a cooling reduction in evaporative cooling performance in a hot and humid climate.

Preventing condensation and frosting in an energy recovery ventilator using a preheat coil

One of the problems presented by energy recovery ventilators (ERV) is the condensation/frosting problem that occurs during winter time. In order to prevent this problem, preheating outdoor air is the most common method used nowadays. The aim of this research is to evaluate preheat coil capacities according to different indoor/outdoor inlet air conditions (temperatures and humidities) and sensible/latent effectiveness of ERV (εS, εL).

Evaluating natural ventilation cooling potentials during early building designs

Natural ventilation (NV) is an efficient way of cooling buildings, and its energy saving potentials however depend on many parameters including local hourly weather and climate conditions, types of ventilations, indoor cooling loads (or heat gains), operating schedules, window types, and opening-wall ratios etc. Determination of the NV flow rate is thus challenging, although there are many empirical equations for different NV strategies, e.g. single-sided and cross-ventilation, considering different driving forces, e.g. wind, buoyancy and a mix of both.

Assessment of airflow measurement uncertainty at terminal devices

Existing protocols for the inspection of mechanical residential systems poorly address both the assessment of uncertainties and recommendations or specifications for measurement methods and devices to be used to guarantee low measurement uncertainties. This paper gives the major elements of a new protocol developed within the Promevent project to overcome this problem. We have analyzed results from 180 airflow measurements performed in laboratory conditions in accordance with this protocol.

Thermal performance of ventilated solar collector with energy storage containing phase change material

This paper presents a ventilated solar collector with energy storage of fins containing Phase Change Material (PCM) in the air cavity and investigates its thermal performance. The idea is to use PCM in combination with ventilation as a thermal controller of indoor environment and to consequently decrease the building energy consumption both in summer and winter time. The main parts of the solar collector are plate fins with small thickness containing PCM fitted into the ventilation cavity, which is a good way to compensate the low thermal conductivity of PCM.

Impact of ductwork airtightness on fan energy use: calculation model and test case

This paper proposes a methodology to assess fan energy use savings when improving ductwork airtightness. This methodology is based on new standard FprEN 16798-5-1:2016. Unlike the classical "cube law", it considers pressure drops at air terminal devices separately from the pressure drops in the rest of the system.

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