Evaluation of ground source heat pump systems for residential buildings in warm Mediterranean regions: the example of Cyprus

This paper presents a feasibility analysis for the installation of ground source heat pump systems in Cyprus. Two reference buildings, a single- and a multi-family one, are designed and analyzed using the EnergyPlus software, in order to calculate their energy needs for heating and cooling for the climate conditions of Cyprus, one of the warmest areas in Southern Europe. These energy needs are assumed to be covered by the conventional heating and cooling systems that are most widely used in Cyprus or alternatively by a ground source heat pump system, which consists of a vertical ground heat exchanger and water-to-water heat pumps and is analyzed using an in-house developed and validated code. Primary energy consumption and the resulting CO2 emissions for both the conventional and the alternative systems are calculated and compared. Results show that the installation of the ground source heat pump system achieves in most cases substantial reductions in primary energy use for both types of buildings. As regards carbon emissions, the findings are less clear: Emissions of the geothermal system are higher than those of the conventional system for the single-family building but considerably lower for the multi-family one. From an economic perspective, the geothermal system compares favorably with the conventional systems in many cases, particularly for the multi-family building

Ground source heat pump systems for residential buildings in warm climates: Energy, environmental and economic considerations

In this paper the heating and cooling energy consumption of a typical single-family house is calculated for five selected locations in Cyprus. Hourly calculations are performed using the EnergyPlus software. The results are translated in oil or LPG and electricity consumption, assuming that the typical building in Cyprus is equipped with an oil-fired or LPG-fired boiler for heating and local air-to-air split-type heat pumps for cooling. The same energy needs are assumed to be covered by an alternative system, i.e. a vertical closed loop ground heat exchanger combined with a water-to-water heat pump system for heating and cooling. The ground source heat pump system is dimensioned with the aid of the EED 3.0 software, analyzed using an in-house developed and validated simulation code, and as a result the electricity consumption of the system is calculated. Based on the resulting fuel consumption of the alternative system, the primary energy consumption and the corresponding emissions are determined, while a financial analysis is also performed. The results prove that significant energy, environmental and economic benefits can be achieved

Ground source heat pump systems for residential buildings in warm climates: Energy, environmental and economic considerations

In this paper the heating and cooling energy consumption of a typical single-family house is calculated for five selected locations in Cyprus. Hourly calculations are performed using the EnergyPlus software. The results are translated in oil or LPG and electricity consumption, assuming that the typical building in Cyprus is equipped with an oil-fired or LPG-fired boiler for heating and local air-to-air split-type heat pumps for cooling. The same energy needs are assumed to be covered by an alternative system, i.e. a vertical closed loop ground heat exchanger combined with a water-to-water heat pump system for heating and cooling. The ground source heat pump system is dimensioned with the aid of the EED 3.0 software, analyzed using an in-house developed and validated simulation code, and as a result the electricity consumption of the system is calculated. Based on the resulting fuel consumption of the alternative system, the primary energy consumption and the corresponding emissions are determined, while a financial analysis is also performed. The results prove that significant energy, environmental and economic benefits can be achieved

Implementation of green roof technology in residential buildings and neighborhoods of Cyprus

Green roofs are considered as an appropriate nature-based measure to increase the environmental resilience of cities. This paper examines this technological solution applied to typical urban residential buildings in the Mediterranean island of Cyprus, with respect to energy, environmental, and economic aspects. The analysis shows a clearly positive energy and environmental contribution of green roofs. Although such an investment does not seem to be cost-effective in residential buildings, sensitivity analysis demonstrates that green roofs become financially favorable compared to flat roof constructions with only modest reductions in their current installation cost. Moreover, green roofs offer environmental benefits that are currently difficult to monetize, which can clearly improve urban resilience to climate change. In order to quantify the impact of green roof installations on the surrounding environment, the analysis was expanded from the individual building perspective to neighborhood scale implementation, using appropriate simulation software to evaluate the contribution of green roofs to urban heat island mitigation. Focusing on the ambient air temperature at the pedestrian level, a noticeable decrease was estimated

Mesenchymal Stem Cell Protection of Neurons against Glutamate Excitotoxicity Involves Reduction of NMDA-Triggered Calcium Responses and Surface GluR1, and Is Partly Mediated by TNF

Mesenchymal stem cells (MSC) provide therapeutic effects in experimental CNS disease models and show promise as cell-based therapies for humans, but their modes of action are not well understood. We previously show that MSC protect rodent neurons against glutamate excitotoxicity in vitro, and in vivo in an epilepsy model. Neuroprotection is associated with reduced NMDA glutamate receptor (NMDAR) subunit expression and neuronal glutamate-induced calcium (Ca2+) responses, and increased expression of stem cell-associated genes. Here, to investigate whether MSC-secreted factors modulate neuronal AMPA glutamate receptors (AMPAR) and gene expression, we performed longitudinal studies of enriched mouse cortical neurons treated with MSC conditioned medium (CM). MSC CM did not alter total levels of GluR1 AMPAR subunit in neurons, but its distribution, reducing cell surface levels compared to non-treated neurons. Proportions of NeuN-positive neurons, and of GFAP- and NG2-positive glia, were equal in untreated and MSC CM-treated cultures over time suggesting that neurons, rather than differentially-expanded glia, account for the immature gene profile previously reported in MSC CM-treated cultures. Lastly, MSC CM contained measurable amounts of tumor necrosis factor (TNF) bioactivity and pre-treatment of MSC CM with the TNF inhibitor etanercept reduced its ability to protect neurons. Together these results indicate that MSC-mediated neuroprotection against glutamate excitotoxicity involves reduced NMDAR and GluR1-containing AMPAR function, and TNF-mediated neuroprotection

The association between cardiac autonomic neuropathy with metabolic and other factors in subjects with type 1 and type 2 diabetes

Background: Cardiac autonomic neuropathy (CAN) is a common diabetes complication associated with poor prognosis. This cross-sectional study aimed to examine for associations between CAN and metabolic and other parameters in patients with either type 1 (T1DM) or type 2 (T2DM) diabetes. Patients and Methods: A total of 600 patients (T1DM, n=200; T2DM, n=400) were recruited. Participants with overt nephropathy, macrovascular complications, and treated hypertension were excluded. CAN was diagnosed when two of the four classical autonomic function tests were abnormal. Results: CAN was diagnosed in 42.0% and in 44.3% of the participants with T1DM and T2DM, respectively. Multivariate logistic regression analysis demonstrated that, in T1DM, the odds [OR (95% confidence intervals)] of CAN increased with higher waist circumference [1.36 (1.01-2.02)], systolic blood pressure [1.16 (1.03-1.31)], hypertension [1.19 (1.03-2.67)], smoking [1.10 (1.12-1.40], fasting glucose [1.01 (1.00-1.01)], HbA(1c) [1.69 (1.07-2.76)], pubertal diabetes onset [1.08 (1.03-1.24)], LDL cholesterol [1.01(1.00-1.02)], triglycerides [1.58 (1.24-1.48)], retinopathy [1.13 (1.04-1.41)], peripheral neuropathy [2.53 (1.07-2.99)], glomerular filtration rate [0.93 (0.87-0.99)], and microalbuminuria [1.24 (1.12-1.36)]. The same analysis in T2DM demonstrated that the odds of CAN increased with higher waist circumference [1.08 (1.00-1.39)], systolic blood pressure [1.06 (1.02-1.12)], hypertension [1.50 (1.24-2.03)], smoking [1.22 (1.14-1.49)], diabetes duration [1.20 (1.09-1.34)], fasting glucose [1.21 (1.12-1.31)], HbA(1c) [1.25 (1.08-1.45)], LDL cholesterol [1.35 (1.04-1.75)], triglycerides [1.30 (1.00-1.68)], retinopathy [1.24 (1.16-1.35)], peripheral neuropathy [1.79 (1.07-2.01)], glomerular filtration rate [0.96 (0.95-0.97)], and microalbuminuria [1.20 (1.14-1.36)]. Conclusions: CAN is common in diabetes and is associated with modifiable factors including central fat distribution, hypertension, dyslipidemia, worse diabetes control, and smoking, and with the other microvascular complications of diabetes. Our findings emphasize the need for a multifactorial intervention for the prevention of CAN. (C) 2011 Elsevier Inc. All rights reserved

Cardiovascular Magnetic Resonance Detects Inflammatory Cardiomyopathy in Symptomatic Patients with Inflammatory Joint Diseases and a Normal Routine Workup

Background. Patients with inflammatory joint diseases (IJD) are more likely to develop cardiovascular disease compared with the general population. We hypothesized that cardiovascular magnetic resonance (CMR) could identify cardiac abnormalities in patients with IJD and atypical symptoms unexplained by routine clinical evaluation. Patients-Methods. A total of 51 consecutive patients with IJD (32 with rheumatoid arthritis, 10 with ankylosing spondylitis, and 9 with psoriatic arthritis) and normal clinical, electrocardiographic and echocardiographic workups, were referred for CMR evaluation due to atypical chest pain, shortness of breath, and/or palpitations. Their CMR findings were compared with those of 40 non-IJD controls who were referred for the same reason. All participants were examined using either a 1.5 T or 3.0 T CMR system. For T1/T2 mapping, comparisons were performed separately for each field strength. Results. Biventricular systolic function was similar between groups. In total, 25 (49%) patients with IJD vs. 0 (0%) controls had replacement-type myocardial fibrosis (p < 0.001). The T2 signal ratio, early/late gadolinium enhancement, and extracellular volume fraction were significantly higher in the IJD group. Native T1 mapping was significantly higher in patients with IJD independent of the MRI field strength (p < 0.001 for both). T2 mapping was significantly higher in patients with IJD compared with controls only in those examined using a 1.5 T MR system—52.0 (50.0, 55.0) vs. 37.0 (33.5, 39.5), p < 0.001. Conclusions. In patients with IJD and a mismatch between cardiac symptoms and routine non-invasive evaluation, CMR uniquely identified a significant proportion of patients with myocardial inflammation. A CMR examination should be considered in patients with IJD in similar clinical settings