Sessions: DDC's next Generation 'Mind Boggling'
The ASHRAE Winter Meeting produced a number of excellent sessions. Following is a recap. Wireless technology, as presented in "State of the Art Issues for DDC Systems," is about to change the course of how control sensors are installed in a building, according to Kris Pister of Dust, Inc., Berkeley, Calif.
The ASHRAE Winter Meeting produced a number of excellent sessions. Following is a recap.
Wireless technology, as presented in "State of the Art Issues for DDC Systems," is about to change the course of how control sensors are installed in a building, according to Kris Pister of Dust, Inc., Berkeley, Calif., and Robert Poor, Ember Corp., Boston.
These two high-powered techies with affiliations at MIT and Cal-Berkeley, posited systems without wires and with sensors a tenth the size of a quarter that contain a battery, a computer, a sensor of any kind, a network card and memory. This device can be placed in each room of an office building and networked to a central computer, which will then summarize and analyze the data collected and control the operations.
One possible application of such technology is having all of a building's fluorescent bulbs and ballasts embedded with a device that can then collect performance information and pass it on to a computer for fault-detection diagnostics (FDD) and performance analysis. To date, both Pister and Poor have implemented actual applications, and more are being developed. The cost factor is about $10 compared to the $80 cost of currently available data loggers.
Data center debate
Discussion in the forum "Mission Critical Data Center Design and Applications: Real-World Problems," raised more questions than answers, but the following practices were recommended:
Improve the data upon which designers can base risk and the chances of a negative incident.
Explore ways to reduce HVAC electrical costs, given that loads will continue to increase.
Find a better way to distribute air and create air movement in a data center in order to get rid of hot pockets.
Explore ways to distribute air at 40°F while overcoming dew point problems.
Federal mold busters
Mold dominated discussion in the second part of the session "HVAC Excellence in Federal Buildings." According to Lew Harriman, director of research and consulting with Mason-Grant, Portsmouth, N.H., the General Services Administration and ASHRAE are working in partnership to make federal buildings less susceptible to mold. Among the steps suggested for designing mold-free buildings:
Use walls that drain moisture outwards rather than trapping it in.
Use overhangs and projections to keep rain off portions of the exterior walls.
Keep water from getting into foundations by sloping finishing grading away from the building and using crushed stone under the building.
Use a dedicated ventilation dehumidification system.
Dedicated ducts, said Harriman, increase the chances of ventilation air reaching the breathing zone and also reduce cooling-tonnage requirements in other systems. Plus, they offer insurance against rain leaks or construction shortcomings; reduce the risk of litigation; and if that's not enough, are required by the P-100 Facility Standards.