nighttime ventilation

The nighttime ventilation strategy uses the outdoor cold air during the night to cool the building mass. The cooled building mass then is used as a heat sink during the next hot day. Mechanical nighttime ventilation requires a fan for the outside air ventilation. The energy use by the fan reduces the potential cooling energy savings. Higher nighttime ventilation flow rate and its duration decrease required cooling energy during next hot day in the building, also they increase fan energy consumption.

The purpose of this study is to evaluate the use of mechanically driven night ventilation in a small bakery shop by looking at the indoor temperature reduction and energy savings produced by the reduction of the cooling load of air conditioning systems. The results from simulations using a validated model based on the TRNSYS simulation environment demonstrate that night time ventilation can reduce peak daytime temperatures in shops without air conditioning. Where a shop has air conditioning, ventilation at night can reduce the cooling load of the air conditioning system.

Describes studies undertaken at an office development. The first study aimed to outline a calculation method to estimate the allowance to be made for heat gains from the building fabric, especially the slab to the supply air in the design of an underfloor air conditioning system. Quantifications had not previously been made of the allowances necessary in the initial calculations as a result of the heat gains. Also gives an overview of the principle of integrating overnight ventilation using fresh air with underfloor air conditioning for so-called 'free' cooling.

A bioclimatic house for Tamare, Venezuela, designed to provide psychological, physical and social well being through improved comfort and less energy consumption is explained. Digital and analog models were built to analyze sunlight and shadow behavior and computer simulations to predict thermal performance. Assuming a maximum comfort temperature of 30° C we achieve<! 95% of satisfaction when we ventilated at night and closed the building during daytime.

Hokkaido is distinguished from the other island of Japan by having colder winters and cooler summers. The average monthly minimum is about -10 °C and summer daily average maximum around 25°C, so that efficient space heating becomes the dominant aspect But on hot days the temperature may reach 35°C, though for short period of time. There are few houses constructed to prevent overheating ID summer. I have designed and built a house for my family ID Sapporo which has cavity walls of concrete blocks insulated with urethane 100mm thick and deeply recessed, but operable widows.