Saving natural gas through smart water heating

Water heating in Pakistan and its neighboring countries predominantly relies on inefficient, natural gas-wasting water heaters whose mechanical design has remained largely unmodified since their inception in the 1960s. The inefficiency of these water heaters has added much to the woes of depleting gas reserves of the region, leading to a widening demand-supply gap. Pakistan is facing its worst ever natural gas crisis due to a COVID-19 hit economy that cannot carry the burden of expensive imports, especially during the Russo-Ukrainian conflict that has sent the gas prices soaring in the international market. We respond to this challenge with a sense of urgency by proposing a solution that minimizes the wastage of natural gas in water heating, which consumes about half the gas supplied to residential consumers in the country. Our solution replaces the mechanical control of the water heater with an IoT-inspired, electrical retrofit design combining hardware and software for smart control through user-defined schedules or machine learning, while solving several challenges that arise from replacing a mechanical control system with an electrical one. Empirical results demonstrate 70% reduction in consumption. © 2022 ACM.

Environmental Benefits and Energy Savings from Gas Radiant Heaters’ Flue-Gas Heat Recovery

This paper demonstrates the need and potential for using waste heat recovery (WHR) systems from infrared gas radiant heaters, which are typical heat sources in large halls, due to the increasing energy-saving requirements for buildings in the EU and the powerful and wide-spread development of the e-commerce market. The types of gas radiant heaters are discussed and the classification of WHR systems from these devices is performed. The article also presents for the first time our innovative solution, not yet available on the market, for the recovery of heat from the exhaust gases of ceramic infrared heaters. The energy analysis for an industrial hall shows that this solution allows for environmental benefits at different levels, depending on the gas infrared heater efficiency, by reducing the amount of fuel and emissions for domestic hot water (DHW) preparation (36.8%, 15.4% and 5.4%, respectively, in the case of low-, standard- and high-efficiency infrared heaters). These reductions, considering both DHW preparation and hall heating, are 16.1%, 7.6% and 3.0%, respectively. The key conclusion is that the innovative solution can spectacularly improve the environmental effect and achieve the highest level of fuel savings in existing buildings that are heated with radiant heaters with the lowest radiant efficiency.

Design Development of Portable (Mini) Multi-function Incinerator for Dry Medical Waste Handling

Medical waste contains biohazard, such as dry medical waste from the Centre of Public Health Services (PUSKESMAS) should be burning out, especially in the pandemic of covid 19. One of the possible solution is burning the waste by using incinerator. Basic concept of incinerator is controlled high temperature combustion, thus it should be perfect condition to burnt out the hazardous waste. Heat energy that exposed while incinerator operated should having high potency to be used for other purposes such as water heater and carbonization process. This research aims to develop an incinerator which can be used not only as high temperature burner (as incinerator’s main function), but also for water heater system and carbonization process, in the same time. The incinerator designed as mini portable incinerator since it will be used in a center of public health services (PUSKESMAS). Both of hot water and charcoal produced while incinerator operation can be used for sanitation purposes in the PUSKESMAS itself. Combustion process temperatures, smoke quality, safety factor, and energy utilities are the parameters which were determined as incinerator performance. Some design improvement has been done to the original design by Pradipta and Agustina [1] in order to improve the incinerator performance. The latest design performance is showing that combustion temperature successfully increased up to 980 °C for combustion rate of 9 kg waste/hour. Utilization of heat energy produced by combustion process inside the chamber has been successfully produce 2-2,5 kg of good quality coconut shell charcoal and hot water of 83 °C at 6 lt/minute flow rate.

Practitioners' perspective on the prevalent water quality management practices for Legionella control in large buildings in the United States

Managing building water systems is complicated by the need to maintain hot water temperatures high enough to control the growth of Legionella spp. while minimizing the risk of scalding. This study assessed water quality management practices in large buildings in the United States. Surveys conducted with building water quality managers found that more than 85% of buildings have hot water temperatures that are consistent with scald risk mitigation guidelines (i.e., < 122..F/50..C). However, nearly two thirds and three quarters of buildings do not comply with the common temperature guidance for opportunistic pathogen control, i.e., water heater setpoint > 140..F (60..C) and recirculation loop > 122..F (50..C), respectively;median values for both setpoint and recirculation loop temperatures are 10..F (6..C) or more below temperatures recommended for opportunistic pathogen control. These observations suggest that many buildings are prone to Legionella spp. risk. The study also found that 27% of buildings do not comply with guidelines for time to equilibrium hot water temperature, over 33% fail to monitor temperature in the recirculation loop, more than 70% fail to replace or disinfect showerheads, more than 40% lack a written management plan, and only a minority conduct any monitoring of residual disinfectant levels or microbiological quality. Given the rise in Legionellosis infections in recent years, coupled with highlighted water quality concerns because of prolonged water stagnation in plumbing, such as in buildings closed due to COVID-19, current management practices, which appear to be focused on scald risk, may need to be broadened to include greater attention to control of opportunistic pathogens. To accomplish this, there is a need for formal training and resources for facility managers.

Disposable DNA Amplification Chips with Integrated Low-Cost Heaters.

Fast point-of-use detection of, for example, early-stage zoonoses, e.g., Q-fever, bovine tuberculosis, or the Covid-19 coronavirus, is beneficial for both humans and animal husbandry as it can save lives and livestock. The latter prevents farmers from going bankrupt after a zoonoses outbreak. This paper describes the development of a fabrication process and the proof-of-principle of a disposable DNA amplification chip with an integrated heater. Based on the analysis of the milling process, metal adhesion studies, and COMSOL MultiPhysics heat transfer simulations, the first batch of chips has been fabricated and successful multiple displacement amplification reactions are performed inside these chips. This research is the first step towards the development of an early-stage zoonoses detection device. Tests with real zoonoses and DNA specific amplification reactions still need to be done.