A Motor for all Climates? Why Not?
Today Laguna Beach's arts community has earned such international renown that it is an increasingly popular place for snowbirds to retire, and that makes HVAC contractors like Randy Scholnick take notice.
"The average snowbird has a pretty basic modus operandi when it comes to figuring out a place to relocate - sunny and dry," said Scholnick, owner and president of Air Doctors, an HVAC contractor in Southern California. "But these new residents often don't realize the substantial diversity of the Southern California climate."
Ten years ago, that factoid would be rather ho-hum to contractors like Scholnick, who sold and installed single-stage HVAC equipment that satisfied the set point, then turned off until needed again. But just as technology profoundly changed our lives through the '90s, computers changed air conditioning as well. In 1999 Scholnick learned about the GE ECM 2.3 blower motor that would revolutionize the future of heating, cooling, and air cleaning.
Scholnick proclaims that the ECM is good news for comfort, convenience, healthfulness and efficiency, and he is on a crusade to advocate this good news. "I'm serious when I say that I got religion on this," said Scholnick. "I believe these variable-speed systems and the ECM are revolutionary equipment."
VARIABLE CLIMATE NEEDS A VARIABLE-SPEED SYSTEMWhile an average Californian might agree that the Golden State's climate is essentially sunny and dry, HVAC professionals like Scholnick know better. A typical Laguna Beach day can look likethis: The morning fog is picturesque but makes for clammy in-door air. Then the morning sun burns off the fog, raising both temperature and humidity by noontime, triggering ocean-borne air currents that stir allergen particulates from the luscious fauna that distinguishes the region. Afternoon and evening temperatures then take a steep drop especially over the ocean, generating cool fronts, which return humidity to the earth.
Now, having lived in this arid, humid, hot, chilly, foggy, allergen-laden, clammy (oh yeah - and sometimes sunny and dry) environment for much longer than the standard two-week vacation, the newly relocated snowbird will begin to sense that their existing system - most likely built on old single-stage technology - isn't quite doing the job. Laguna Beach has been such a nice place to visit for its snowbirds, but the weather brings to question if they could retire here and be comfortable as well.
THE BIG PART OF THE ECM'S BIG PICTUREThe reason that a customer's indoor climate seems indistinguishable from the outside is often due to the airflow limitations of a standard PSC motor. For example, through the morning and early day when sensible cooling demand is light, frequent cycling produces blow-off moisture from the coil, thereby reintroducing humidity to the home. This in turn sustains the clammy atmosphere, which defeats the whole purpose of turning on the air conditioning system in the first place.
To complicate matters, the sunny southern half of the house often can be 10 to 15° warmer than the northern half because of a one-zone duct system that cannot redirect the needed supply air.
Scholnick said the key to greater indoor comfort is the airflow con-trol afforded by the GE ECM 2.3. "It has turned the traditional PSC-driven system into a programmable, multiairflow system that runs with different settings called comfort profiles," he said. The profiles are stored in the onboard computer that can continually adjust airflow so that each room maintains the same humidity, temperature, and particulate levels.
Pre-Run profile in the morning, for example, starts the cooling mode and requires a much different airflow than heating mode. Pre-Run allows for a reduced airflow capacity at compressor startup. In humid climates, like Laguna Beach in the morning or Atlanta in August, a reduced percentage of the maximum cubic feet per minute (cfm) can be selected to allow more moisture to collect and drain from the coils.
But that was then; this is now. Only a few hours into the morning, Laguna Beach is becoming a different climate. The variable-speed ECM now kicks into Short-Run profile to achieve the preferred degree of dehumidification and to reduce re-evaporation. The Off-Delay profile can allow the blower to run for a period of time after the compressor shuts off, which is useful in arid and moderate climates to re-evaporate moisture into the air. In humid climates this time is programmed to zero in order to minimize re-evaporation of the evaporator coil and drain pan moisture back into the conditioned space.
These profiles enable consistent home comfort even while the climate outside changes. Through the evening and early morning hours, an absence of cloud cover coupled with an ocean breeze can initially create a humid and chilly night. Then as the humidity settles on the terrain, moisture collects on the ground, which can result in a dry and chilly night. The variable ECM can then switch to its heating profiles.
One possible profile for a gas or oil furnace is to have a short Pre-Run delay at a very low cfm until the heat exchanger is up to an adequate temperature. At the end of the heating cycle, an Off-Delay can improve system efficiency by continuing to move air across the exchanger until the residual heat is removed.
In the case of electric heat, a rapid On-Slew rate to full capacity prevents the coils from overheating. Likewise, a rapid Off-Slew rate will prevent blowing cool air into the home after the heating coils have shut off. If thermal relays are used to control the heating coils or if coils are staged, then the On-Slew, Pre-Run heating and the Off-Slew profiles can be set at different rates to match relay performance.
Unique requirements of heat pumps can also be accommodated by matching delays to individual system performance characteristics. An emergency or backup profile can also be created to match system response to a call for secondary heat in the heat pump application.
BOOMING OPPORTUNITY FOR HVAC PROFESSIONALSTo call Scholnick an evangelist for GE's ECM is hardly a stretch. "This is why I'm such a believer in the variable-speed systems," he explained. "A single-speed system just doesn't process the air like a variable speed can. With all these different air qualities in a single day, a system that just knows â€˜on/off' can't match a system that has multiple stages and can speed up or slow down according to the need of the moment."
Scholnick is also learning something very important regarding his bottom line: More snowbirds are coming. An estimated 76 million men and women will officially begin retiring in the year 2011 and this means a lot of people are now beginning to demand a lot of products and services from the health and comfort industries.
The baby boomers - babies born between the years of 1946 and 1964 - arrived after servicemen returned home from World War II in 1945 and started families. This generation caused a boom of school and church construction in the '50s, a boom of higher education demand in the '60s, a glut of underemployed laborers in the '70s, and an unprecedented economic boom in the '80s and '90s through its voracious appetite for innovative products and services.
In the words of one economist, the baby boomers' collective impact on our society has been like "watching a pig go through a python" and as this generation approaches its twilight years, HVAC professionals have an opportunity - a booming opportunity - to provide a standard of comfort, convenience, environmental efficiency, and healthfulness to an unprecedented swell of consumers with disposable income, coupled with a keen desire to live well.
But HVAC professionals have a lot of educational work cut out for them in order to realize this potential. "Most people don't know [the ECM 2.3 variable-speed motor coupled with a two-stage system] is even an option," Scholnick said. "They don't know how drastically the technology has changed over the past 10 years and what they can have if they only understand what is at stake a little more."
The snowbirds are coming, and HVAC professionals need to get prepared to convey just how comfortable and healthy their new perches can be.
Publication date: 04/10/2006