Experimental investigation on hygrothermal behaviour and the surface condensation risk of a data centre

Condensation under the floor slabs of office rooms adjoining data centres is a serious concern because thermal comfort and information and communications technology equipment are both sensitive to high humidity levels. Surface condensation risk depends mainly on the surface energy balance and moisture content of ambient air. This paper describes an evaluation method for assessing condensation risk of indoor environment conditions and the effect of remedial measures and presents a strategy to solve the condensation risk problems using experimental measurements and numerical simulations. The condensation risks due to air temperature and humidity were calculated for two zones between information and communications technology server rooms and office areas. We analysed the structural insulation performance and space cooling conditions, supply air temperature of the information and communications technology server rooms. The change in indoor temperature of non-information and communications technology spaces was predicted to find the cause of the condensation state. The results show that application of floor slab insulation and high supply air temperature by the computer room air-conditioning unit can substantially increase the lowest temperature of the interior surfaces and the temperature factor and reduce indoor relative humidity, thus preventing surface condensation in the non-information and communications technology spaces adjacent to the information and communications technology server rooms.

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Energy-Efficiency Through the Integration of Information and Communications Technology Management and Facilities Controls

ASME 2009 InterPACK Conference, Volume 2 ◽

10.1115/interpack2009-89359 ◽

2009 ◽

Cited By ~ 3

Author(s):

Michael K. Patterson ◽

Michael Meakins ◽

Dennis Nasont ◽

Prasad Pusuluri ◽

William Tschudi ◽

...

Keyword(s):

Energy Efficiency ◽

Air Temperature ◽

Data Center ◽

Temperature Sensor ◽

Data Centers ◽

Cooling System ◽

Information And Communications Technology ◽

Demonstration Project ◽

Communications Technology ◽

Control Loop

Increasing energy-efficient performance built into today’s servers has created significant opportunities for expanded Information and Communications Technology (ICT) capabilities. Unfortunately the power densities of these systems now challenge the data center cooling systems and have outpaced the ability of many data centers to support them. One of the persistent problems yet to be overcome in the data center space has been the separate worlds of the ICT and Facilities design and operations. This paper covers the implementation of a demonstration project where the integration of these two management systems can be used to gain significant energy savings while improving the operations staff’s visibility to the full data center; both ICT and facilities. The majority of servers have a host of platform information available to the ICT management network. This demonstration project takes the front panel temperature sensor data from the servers and provides that information over to the facilities management system to control the cooling system in the data center. The majority of data centers still use the cooling system return air temperature as the primary control variable to adjust supply air temperature, significantly limiting energy efficiency. Current best practices use a cold aisle temperature sensor to drive the cooling system. But even in this case the sensor is still only a proxy for what really matters; the inlet temperature to the servers. The paper presents a novel control scheme in which the control of the cooling system is split into two control loops to maximize efficiency. The first control loop is the cooling fluid which is driven by the temperature from the physically lower server to ensure the correct supply air temperature. The second control loop is the airflow in the cooling system. A variable speed drive is controlled by a differential temperature from the lower server to the server at the top of the rack. Controlling to this differential temperature will minimize the amount of air moved (and energy to do so) while ensuring no recirculation from the hot aisle. Controlling both of these facilities parameters by the server’s data will allow optimization of the energy used in the cooling system. Challenges with the integration of the ICT management data with the facilities control system are discussed. It is expected that this will be the most fruitful area in improving data center efficiency over the next several years.

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Analysis of indoor environment and insulation performance of residential house with double envelope vacuum insulation panels

International Journal of Solar Thermal Vacuum Engineering ◽

10.37934/stve.3.1.1528 ◽

2021 ◽

Vol 3 (1) ◽

pp. 15-28

Author(s):

Takao Katsura ◽

Tomoya Ohara ◽

Taichi Kamada ◽

Katsunori Nagano ◽

Saim Memon

Keyword(s):

Air Temperature ◽

Indoor Environment ◽

Room Temperature ◽

Thermal Environment ◽

Ambient Air ◽

Vacuum Insulation ◽

Residential House ◽

Heating Load ◽

Insulation Performance ◽

Double Envelope

Double envelope vacuum insulation panels (VIPs) have a possibility to significantly increase the service lifetime. In this paper, double envelope VIPs were produced and installed in the residential house. The performance of installed VIPs was evaluated by using the measuring data of heat flux meter. In addition, the total energy, the heating load and the indoor thermal environment of this house were measured and analysed. The average heating load and the average temperature difference between room temperature and ambient air temperature on the representative day was 2.49 kW and 29.9 oC, respectively. The heat loss coefficient per floor area was estimated as 0.69 W/(m2K) and it was almost the same as the value calculated at the time of design. The result of indoor environment measurement showed that the room temperature was maintained at around 20 oC and PMV was -0.5 oC or higher although the outside air temperature fluctuated between -5 oC and -10 oC. The effective thermal conductivities of double envelop VIPs were all estimated as 0.01 W/(mK) or less. It is considered that the insulation performance of the vacuum insulation panels is maintained.

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Evaluation of Abaya Design Using Thermal Manikin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.834-836.1744 ◽

2013 ◽

Vol 834-836 ◽

pp. 1744-1748

Author(s):

Salwa Tashkandi ◽

Sinnappoo Kanesalingam ◽

Li Jing Wang

Keyword(s):

Relative Humidity ◽

Thermal Insulation ◽

Air Temperature ◽

Ambient Air ◽

Thermal Manikin ◽

Ambient Air Temperature ◽

The Mean ◽

Skin Temperatures ◽

Insulation Performance

The main objective of this research was to measure the thermal insulation using a thermal manikin dressed in various ensembles of clothing within the abaya. A range of clothing and abaya has been tested using a heated manikin. The thermal manikin experiments were conducted in dry condition. The ambient air temperature for the dry tests was set at 23oC and Relative Humidity at 50% and the mean skin temperatures averaged at 35oC. The results showed that the daily clothing and abaya affect the thermal insulation performance. It is uncomfortable to wear more layers of the daily wear clothing within the abaya. The abaya worn over the head thermally insulated slightly more than the abaya worn from the shoulder.

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