Volume 71, March 2014, Pages 28–37 Stuck in a stack—Temperature measurements of the microclimate around split type condensing units in a high rise building in Singaporea b c d Received 7 June 2013, Revised 24 October 2013, Accepted 12 November 2013, Available online 23 November 2013•First field experiments on stack effect induced by split type air-conditioners.•Temperature rise of 10–13 °C over 20 storeys due to stack effect.•Temperature rise of 9 °C due to “stuck effect”, caused by recirculating hot air.•Measured on-coil temperatures of 50 °C for upper storeys.•Significant performance reduction, COP reduced by 18% (stack only) 32% (combined).The use of air-conditioning, the largest energy demand for buildings in the tropics, is increasing as regional population and affluence grow. The majority of installed systems are split type air-conditioners. While the performance of new equipment is much better, the influence of the microclimate where the condensing units are installed is often overlooked.

Several studies have used CFD simulations to analyse the stack effect, a buoyancy-driven airflow induced by heat rejected from condensing units. This leads to higher on-coil temperatures, deteriorating the performance of the air-conditioners. We present the first field measurements from a 24-storey building in Singapore. A network of wireless temperature sensors measured the temperature around the stack of condensing units. We found that the temperatures in the void space increased continuously along the height of the building by 10–13 °C, showing a significant stack effect from the rejected heat from condensing units. We also found that hot air gets stuck behind louvres, built as aesthetic barriers, which increases the temperature another 9 °C. Temperatures of around 50 °C at the inlet of the condensing units for floors 10 and above are the combined result, reducing the unit efficiency by 32% compared to the undisturbed design case. This significant effect is completely neglected in building design and performance evaluation, and only with an integrated design process can truly efficient solutions be realised.

Graphical abstractKeywords; ; ; ; ; ; ; ; 1. Introduction and backgroundWhile we researchers strive to increase energy efficiency and reduce greenhouse gas emissions from building operation, society continues to increases its expectation of the built environment. Just as European societies moved away from fireplaces and ovens as central heating technology became available, now developing countries expect more and more air conditioning. This is especially true in the rapidly growing market for individual split type or window type air-conditioning units, which ever more people are gaining access to in the developing world and large population centres in the tropics. If we are to address conglomerate growth of energy demand we must address the large-scale design and installation of these small system. The unchecked installation of split units has had a dramatic effect on façade aesthetic and form in places like Singapore, and the heat rejected by these systems is also largely unaddressed.

We present for the first time experimental findings on the impact on local temperatures of the heat rejected from split units installed throughout a 24 story building in Singapore. free standing ac unit reviewOur results uncover a major influence on the temperatures adjacent to the building that will affect both comfort and the expected performance of the system, significantly lowering the efficiency of the air-conditioning equipment and degrading the comfort.air conditioning units for hot water heat homesThis reduced performance erodes away successes in increased efficiency in buildings, which must be broadly addressed because the energy used to create, operate and deconstruct buildings is a major anthropogenic contributor to greenhouse gas emissions and thus climate change. central air conditioner ratings 2011

76% of the total electricity consumption in the US is used for buildings [1]. Due to their static nature and much untapped improvement potentials, buildings also represent a major opportunity for the reduction of further emissions. In the hot-humid tropics of Singapore, roughly 50% of the energy consumption in buildings is used for air-conditioning [2]. In 2007, 75% of all households were (partly) air-conditioned, a number that has certainly increased since [3]. Similar developments are expected in surrounding countries with increasing population and wealth.By proxy there is evidence of the rise in the simple air conditioning solutions in the production of R-22, a refrigerant commonly used in small air-conditioners. It has been shown to be rapidly rising in developing countries [4]. This is a dangerous indicator for the further development of climate change, primarily in regard to the high global warming potential of R-22, but also as a significant indicator for the expanding installation of these types of small units.

They are often sold as DIY units with a lack of professional installation that may address issues of proper spacing, setbacks from walls, and adequate air supply, all of which degrade an already limited performance. Even without the proxy data of R-22, it only takes a quick look around any of the rapidly growing cities in the tropics to realise the prevalence of these systems as shown clearly in Fig. 1.Your Vivint Smart Thermostat will save money and energy when you make the most of its scheduling options and remote access via your smartphone or tablet. Set Heating & Cooling Schedules Enable the Auto-Fan Off Feature Change the Temperature Display Unit Turn the Touch Tone On/Off Lock your Vivint Smart Thermostat Set the Swing Temperature Adjusting your Thermostat HVAC Settings Thermostat Not Visible On App/Online Heat Pump Not Functioning Properly What do I do if the temperature on my thermostat is reading Celsius when it should be reading Fahrenheit (or vice versa)?