control strategy

This paper investigates the dynamic cooling performance of a novel system combining natural ventilation with diffuse ceiling inlet and thermally activated building systems (TABS). This system is tested in the lab under three climatic conditions representing typical seasons in Denmark, including a typical winter day, a typical day in the transitional season and a typical summer day. The corresponding dynamic control strategies have been designed for these three cases in the measurements.

Nearly all retail locations use mechanical cooling systems to ensure indoor comfort temperatures and mechanical ventilation to ensure adequate air exchange, primarily for hygienic reasons. Because of the big volumes involved and the lack of knowledge in natural ventilation design, shopping centres designers have been relying on basic HVAC equipment, without considering the potential of ventilative cooling to reduce cooling needs and to maintain an acceptable indoor environmental quality.

The most representative typology of residential buildings of Catalonia has been simulated in TRNSYS to evaluate the impact of both infiltration and natural ventilation. The typology is a block of apartments constructed during 1950-1980. 

The decrease of heat demand in low energy build-ings, very sensitive to solar and internal gains, and the development of new HVAC systems call for a reexam-ination of the usual modeling approaches in building simulation. A focus is brought on an air-to-water heat pump plugged to a radiant heating floor (RHF) by a hydraulic loop installed in a typical low energy dwelling. Using a RADTEST evaluated Modelica slab model, several floor thermal masses under four differ-ent control strategies are compared to determine their impact on HVAC system performances.

An earth-to-air pipe type heat exchanger (EAHE) is a simple and effective ventilation system component, used for preconditioning of the fresh air supplied to a building. This paper presents two sets of results of operational parameters long-term measurements and energy analysis of EAHEs, located under two different retail buildings of floor area over 1000 square meters each.  

The control strategy for mechanical ventilation systems has significant impact on the performance of the system, in terms of energy consumption and correct air distribution. This paper presents a static pressure reset control system employing a new type of flow damper with lower pressure loss for use in low pressure ventilation systems. The flow damper has a droplet shape that minimizes turbulence generation and the resulting pressure loss. The performance of the damper was examined by making measurements of pressure loss and airflow.

This paper presents an investigation into solutions for the system design of a centralized DCV system in multi-family dwellings. The design focused on simple and inexpensive solutions. A cost benefit estimate showed that the initial cost of implementing DCV in a system with an efficient heat exchanger should not exceed 3400 DKK per dwelling in regions with weather conditions similar to the Danish climate. A design expected to fulfil this requirement was investigated in detail with regard to its electricity consumption by evaluation of different control strategies.

Results are presented from a study of the performance of fuzzy, rule-based algorithms for thecontrol of indoor air quality through combined control of natural and forced ventilationstrategies, whilst simultaneously meeting thermal and visual comfort requirements as part of aglobal control strategy aimed at optimizing the indoor environment with minimum energyconsumption.