Low-temperature systems can improve energy efficiency and hence reduce fuel consumption and CO2 emissions. There is growing interest in low-temperature hydronic central heating systems, ie those where water is used as the medium to distribute heat around the building, and in which the water leaving the heat generator is limited to a lower temperature than in normal system design. This BRE Trust Report is aimed as a guide for those who wish to install low-temperature heating systems in dwellings, and concentrates on the calculations and other conditions necessary to ensure that low-temperature operation can be achieved. It became apparent during the preparation of this guide that there is no generally well-established and understood design method for low-temperature domestic heating systems. Instead of simply gathering information on current practice, the authors found it necessary to engage in extensive debate about many of the technical parameters governing system sizing, configuration and selection of components. Some of these have not been fully resolved. In particular, leading designers should give more attention to:-selection of a representative external temperature for heat loss calculations-allowance for building exposure-suitable heat loss calculators, conforming to stated rules-refined intermittency factors, perhaps using the advanced method set out in BS EN 12831:2003-evaluation of emitter responsiveness, especially for emitters with fans-temperature-limiting controls, and modulation by reference to an upper temperature limit.The last item (controls) is especially important, as it is the water temperature at the heat generator that is the principal determinant of efficiency when low-temperature system designs are contemplated. Further development of standard design and operating practices (especially for controls) for low-temperature systems will be necessary before low-temperature systems can be recognised as a mature option capable of providing energy savings in all cases. ContentsExecutive summaryPart 1: The benefits and technical aspects of low-temperature heating1.1 Introduction1.2 What is low-temperature heating?1.3 Efficiency improvement potential1.4 Comparison of performance with conventional heating systemsPart 2: Design procedure for designer and installer2.1 Importance of correct heating system design2.2 Calculation of the heat loss from each room2.3 System parameters affecting emitter size2.4 Determining emitter sizes2.5 Selection of suitable heat emitters2.6 Oversize factor for radiators and convectors2.7 Controls to achieve low-temperature conditions2.8 Installation, commissioning and labelling2.9 Completion certificate2.10 ReferencesPart 3: AppendicesA Design, installation and commissioning checklistB Example design, installation and commissioning compliance certificateA4, 28pp, 13 line drawings, 3 photos
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In cases of epileptic encephalopathy besides IS, epilepsy severity does not necessarily impact neurobehavioral outcomes. STXBP1-related encephalopathy is one example. STXBP1 encodes syntaxin-binding protein 1, which helps regulate synaptic vesicle release [81]. Defects in this gene result in an epileptic encephalopathy [82] accompanied by ID, motor abnormalities (hypotonia, ataxia, tremor, spasticity, dyskinesia, dystonia), and ASD features [43]. Stamberger et al. [43] analyzed the relationship between cognitive outcomes and epilepsy severity in 147 patients with STXBP1 encephalopathy, 95% of whom had epilepsy (including 21% who presented with OS, 9.5% who presented with West syndrome (WS), and 53% who presented as early-onset epilepsy and encephalopathy). The authors did not find a statistically significant relationship between level of cognitive impairment and either age at seizure onset or length of time from seizure onset to seizure freedom (ASD severity was not a reported outcome), though they did acknowledge that the study was underpowered. Furthermore, in this analysis, as noted above, about half the cases were early-onset epilepsy and encephalopathy, which is a different entity from epileptic encephalopathy [43]. 2ff7e9595c
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