Here, the epidemiologic evidence from the past decade of high ambient temperature and mortality is summarized, with a closer examination of.
Multi-city analyses are preferred, since bias from a single city analysis may result and the findings from multiple areas may be more generalizable. Thus, city or county-level estimates are usually combined into one overall estimate using meta-analytic techniques using a random effects model.
Much of the focus of epidemiologic studies has been identifying cause-specific outcomes and vulnerable subgroups of mortality from high ambient temperature (Table (Table3 3 ).
Forty-nine studies specifically addressing mortality due to heat waves or high ambient temperatures had been published in peer-reviewed and.
In evaluating studies of temperature and mortality, the following methodological issues should be considered: 1) assessment of exposure and outcome measures; 2) selection of an appropriate study design; and 3) use of statistical models to describe the temperature-mortality relation.
“Harvesting” refers to a brief temporal advancement of death among persons who are already ill or frail and at high risk of dying. Through examination of intermediate- and long-term effects, rather than only short-term effects, time domains are assessed in which the impact of harvesting is reduced ( 35, 36 ).
Lead Performer: Oak Ridge National Laboratory – Oak Ridge, TN Partners: Navigant Consulting, Inc. – Burlington, MA.
ORNL effort is part of a global initiative to avoid going through two consecutive transitions: from HCFC to HFC and then from HFC to low-GWP refrigerants. This work was primarily focused on high-ambient temperature environments similar to environments encountered in developing countries (Article 5 Countries according to the Montreal Protocol).
The results indicated that several of the available refrigerants could be used with soft optimization to match the performance of existing units. Performance evaluation of alternative low-GWP refrigerants at ORNL showed promising environmentally friendly solutions for R-22 and R-410A replacement.
DOE Technology Manager: Patrick Phelan Lead Performer: Omar Abdelaziz, Oak Ridge National Laboratory.
Lead Performer: Oak Ridge National Laboratory – Oak Ridge, TN Partners: Navigant Consulting, Inc. – Burlington, MA DOE Funding: $530,000 Project Term: March 2015 – March 2016.
Image: ORNL. Performance of alternative refrigerants compared with R-22 (mineral oil) at extreme test conditions (outdoor temperature 55°C and indoor temperature 29°C).
Forrestal Building 1000 Independence Avenue, SW Washington, DC 20585.
Performance of alternative refrigerants compared with R-410A at extreme test conditions (outdoor temperature 55°C and indoor temperature 29°C). Image: ORNL.
ORNL worked with an original equipment manufacturer who provided equipment designed for the high ambient environments and all the major refrigerant manufacturers to evaluate their candidate alternative in the baseline systems. The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for Low-GWP Refrigerants aims to develop an understanding of the performance of lower global warming potential (low-GWP) alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions.
Block and Tackle Series Volume 2 – Motor Derating Due To High Ambient Temperatures. Question: How do I calculate a motor's continuous.
This is most often done by graphically determining T r (40°C) at the desired RPM from the motor’s PC and using it in place of T c (40°C), in the above formula.
How do I calculate a motor’s continuous torque when it is operating in an environment above its rated temperature? Since the motor’s continuous torque (Tc) is rated in a 40°C ambient, how can I estimate the motor’s continuous torque during my worst-case ambient temperature of 55°C? Answer:
He can be reached at. You can also connect with this author at Google+. Hurley Gill is a 1978 Engineering Graduate of Virginia Tech who has been engaged in the motion control industry since 1980. Hurley is often called upon to deal with the toughest of applications for Kollmorgen.
where ΔTemp Rated = Temp(maximum winding) – Temp(rated ambient).
Torque required, T r (new) at a specific RPM, can also be estimated by graphically finding the maximum continuous capability with the specified ambient temperature at the desired RPM, from the motor’s performance curve (PC), if not available from the motor’s data sheet.
40°C ambient). First you will need to know the maximum winding temperature of the motor based on the published ratings data (e.g.
Assuming it is given to be 100°C, the maximum winding temperature = 140°C). If not directly given within the motor’s catalog data, it can be determined by adding the 40°C to the published delta (Δ) Temperature of the winding (assuming it is given; if not, you will need to contact the motor’s manufacturer.
The condenser fan cycles off in low ambient temperature conditions, thus NOTE: Low Ambient option MAY NOT be combined with High Ambient option, unless.
NOTE: Low Ambient option MAY NOT be combined with High Ambient option, unless pre-approved by engineering as a custom build unit.
Download PDF version: AC options – Ambient Packages Top.
Heat is applied inside the compressor, where it is needed, to protect it from damage or wear due to stalls and hard starts after long periods in the non-cooling state. The low ambient option consists of circuitry to protect the compressor in a low ambient temperature environment.
This works together with the pressure controlled condenser fan in all Thermal Edge air conditioners. This also reduces the current inrush by not starting the condenser fan when the compressor is turned on. The condenser fan cycles off in low ambient temperature conditions, thus allowing rapid warm up.
All information subject to change without notice.