Let me just go right ahead and say it; I think ductwork looks neat. I do. I like brightly painted spiral duct with elbows and offsets. I like rectangular duct with flanges and cross-breaking. And, of course I like the appearance of diffusers and grilles installed on the sides and ends of ductwork. Unfortunately, not everyone has the same artistic eye as me. I suppose there are some wide open architecturally significant spaces that that might be better off without a bunch of “%^$#@ ductwork.”
One option to hiding ductwork is to serve the spaces from below. Ductwork under slab is not a new concept, but the problems associated with installing ductwork under the floor slab have caused it to be an option rarely selected. Water leaks, installation challenges, VOCs, deterioration and first costs associated with the current methodology are liabilities for contractors, architects and end users.
I’m here to tell you that it is now safe to go back underground. Blue Duct is an HDPE product that does not have VOCs, has thermal insulation properties, will not rust, installs faster than other options and is air and water tight. It meets building codes across North America.
Blue Duct is a problem solver. Now architects and engineers have a safe, robust and economical means of providing air conditioning and heat to a large volume of spaces without needing to clutter the space. Applications include: air displacement ventilation systems, spaces where overhead ductwork is not an option, natatoriums, auditoriums, churches, residential and most anywhere else.
R.L. Craig Company has already provided Blue Duct on several projects in Kentucky and Southern Indiana. Let me know when you are ready to go underground. firstname.lastname@example.org; www.blueduct.com.
We’re all familiar with small direct drive fans and “speed controllers”. These speed controllers are rheostats which consume, or waste, energy before it gets to the PSC fan motor, slowing the motor to a desired speed. They have been in place now for many decades in North America’s schools, offices, factories, commercial spaces, and homes. But, the consumption of energy before it even gets to the motor creates heat and is not very “green”. They are inefficient by the standards of the new technology that’s been finding its way into new HVAC systems throughout the States, Canada, and beyond.
Now that brushless DC motors, also called electronically commutated motors (ECM), are mass produced, their competitive pricing makes them the obvious choice over PSCs and rheostats.
The electronically commutated motor only uses the amount of energy necessary to obtain the desired air flow, unlike the PSCs and rheostats. They also can be adjusted from 0 rpm to 100% rpm, while the rheostats should only be adjust from 70% rpm to 100% rpm.
Furthermore, the ECMs allow for much greater flexibility in terms of speed control and operation of the fan. They can be manually adjusted with a dial on the side of the motor, manually adjusted with a remote mounted dial, or receive a 0-10 vdc control signal from the building management system. Small exhaust fans can automatically turn off or on or modulate as required.
Direct drive fans with ECMs use less electricity and are more likely to be controlled to meet the needs of the space, also saving energy dollars. Sounds like a revolution to me. For more information, click here.
Time and again, the technologies that comprise our HVAC industry have changed. New installation techniques, not to mention whole new concepts for ventilation, make their impact felt on a yearly basis. It can be difficult at times to keep pace with the fluidity inherent in our industry. Perhaps strangest of all, it is difficult – in fact quite impossible – to find a comprehensive textbook or reference book that compiles the “tribal knowledge” of HVAC industry into a single document. The fact that universities offer little in the way of HVAC programs hasn’t been helpful to our line of work either. Time and again, it has been up to individual HVAC engineers to take apprentice technicians “under their wing” to teach them the A-to-Z of all things HVAC.
Thanks to Gerry Price and Price Industries, that has changed. Price has developed an Engineer’s HVAC Handbook that takes an HVAC designer through all the ropes and rigors of air distribution and HVAC Fundamentals. Two years in the making, with over 50 team members compiling 20,000+ hours of HVAC facts and figures, they incorporated 60+ years of data and experience from venerable organizations and associations such as ASHRAE, AHRI, NVLAP, AMCA, and others.
Weighing in at 1,300 pages, with over 1,000 separate illustrations, and reviewed by 26 external reviewers in order to insure unbiased content, at last, our industry has a locus point for its knowledge. You could call it the Encyclopedia HVAC-ia (though we would not recommend it). 16,000 copies of the book have already been sent out. Let me know if you, your employees, or your students would be interested in the handbook.
Although the concept and application have been around since 1978 (first commonly used in Scandinavia), it’s only been fairly recently that displacement ventilation has come to North American shores. It’s somewhat surprising that it’s taken this long, given that displacement ventilation now counts for the air conditioning of roughly 25% of the total corporate offices in Nordic countries, and has been incorporated into large construction jobs like Bangkok, Thailand’s Suvarnabhumi International Airport.
Displacement ventilation is a less costly and more environmentally-sound indoor cooling solution than traditional HVAC systems: it’s been proven to provide lower utility costs, as well as cleaner air, to the spaces where it’s been instituted. It manages this by the efficient means through which it distributes cool air: instead of the cool air coming from a single air handling unit in a room, the cool air gets distributed throughout the floor, then rises gradually upwards (in what are called “thermal plumes”) as it comes into contact with the heat of the room. Each thermal plume provides enough draft to convey the gradually heated air up to the ceiling of the room, whereupon it gets dispersed by way of exits.
As mentioned before, the technology is relatively new to the United States and Canada. Nevertheless, we at R.L. Craig anticipate a growing number of individuals and companies adopting displacement ventilation for their homes and businesses, on account of its cleanliness and cost-effectiveness. One of the recent American adapters of displacement ventilation was NASA’s own Jet Propulsion Center; it’s only a matter of time before other industries follow aerospace’s lead into this tried and proven means of providing clean, cool air.