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Performance & Simplicity of Controls Spark Interest

June 1, 2006
Liza Mathew, manager of controls for Carrier Corporation, sees much improvement in the development of consumer-friendly HVAC controls.

New consumeroriented sales tools will be released by Carrier to help dealers demonstrate ease of use to customers. The Infinity System 'Tutor' consists of a demo Infinity Control with its own power supply, and a flip chart detailing all the consumer benefits.

Carrier's Infinity System.


Liza Mathew, manager of controls for Carrier Corporation, sees much improvement in the development of consumer-friendly HVAC controls.

"Every manufacturer on the cutting edge wants to make their thermostats consumer friendly," says Mathew. "The key is to make them so consumer friendly that the homeowners don't need an instruction manual."

According to Mathew, many homeowners express interest in state-of-the-art technology, but confess to feeling some trepidation over the learning process.

"Dealers and real estate agents are usually interested in selling up to programmable thermostats," says Mathew.

"If you explain the benefits to the consumer, they're also usually willing to spend the extra dollars for a programmable thermostat; but there's still some work to be done among consumers in making thermostats 100% consumer friendly, especially in areas related to programmability."

Unlike the homeowner's VCR that's never been programmed, Mathew cites cell phones as an example of "complicated" technology that's been refined to the point of ultimate ease of use for consumers; HVAC manufacturers face a similar challenge.

"You want the same kind of usability with a thermostat," Mathew says, "even if they don't use it every day. Homeowners are very interested the first time the thermostat is installed, but four months later, they get frustrated and put it on 'hold.' They spend the extra money for the high efficiency, programmable unit and then don't use it. They'll tell you it's 'too difficult to program.'"

Mathew cites Carrier's Infinity™ System user interface as an example of improved programmability. Its day-at-a-glance programming option lets consumers customize heating and cooling needs around their daily schedules without having to search for a homeowner's manual. Intuitive, on-screen prompts walk the consumer through the programming options, and lets them save changes or return to previous settings.

A Callback Just to Set a Thermostat
Mathew also emphasizes the importance of easy installation for contractors.

"If you have to go back to the jobsite to explain to the consumer how to use it; or if you have to return to the jobsite because it was installed incorrectly, you've lost your margin on that thermostat.

You have to get it right for the dealer, so you have to make it easy to install."

Typically, says Mathew, the complexity of some thermostats and other older model control products makes it difficult to write accompanying product literature.

More simplified, yet still advanced wiring is making that job easier.

"With Infinity, you don't have to worry about wiring to the right terminals depending on the type of equipment. At power up, the Infinity Control has built-in automatic start-up, eliminating the need to set dip switch settings and configure equipment.

"Every home thermostat has at least four wires, so we use the existing four wires, and connect it to a Carrier system. It has two wires for communication, and two wires for power that are color coded and alphabetized ('ABCD' wiring)."

Infinity identifies they type of system it's working with, and which type of heat is being used (gas or electric), and whether the system is using UV lights or a ventilator.

"The contractor answers 'YES or ' NO' to a series of questions, hits ' SAVE,' and the system operates according to all the system characteristics."

Infinity performs a static pressure check and duct assessment, adapts to different variables that are unique to different homes, and detects how much CFM is going into each zone. If one of the zone dampers doesn't open, the Infinity zoning control identifies which zone is wired incorrectly or which damper is stuck.

Bottom line: thermostats might be relatively inexpensive items when compared to an entire HVAC system, yet it's very true that the system will lose some of its luster if the thermostat becomes a source of frustration. "Contractors are dealing with furnaces and fan coils every day, and a thermostat can cost less than $100; but you won't have a successful product unless you make it easy for the dealers to install and consumers to use," says Mathew.

Only as Good as the Maintenance
Even a state-of-the-art system will fail without regular service. The key message for homeowners, says Mathew, is that filter changes and other annual maintenance ensure comfort system efficiency.

But just to be sure systems receive timely attention, some advanced controls now display maintenance alerts, routine maintenance reminders which help keep the systems clean and efficient.

Infinity's alerts are activated based on pressure readings, and there are other alerts that are based on time.

It's all about averting a high service bill.

"Dirty filters increase the pressure drop, and can eventually cause the coil to freeze up," warns Mathew, "when all you really needed to do was change the filter."

Opinions: dehumidification technology and controls
Tom Mooney, a systems analyst with CCAC Air Conditioning, Corpus Christi, TX, has gained a solid reputation as a dependable dehumidification expert.

Mooney sells as many as a dozen Thermastore whole house dehumidifiers each month in the humid climate of Southern Texas, as a successful antidote for dust mites, which he says are the world's number one indoor air quality problem.

Mooney helps customers understand that an air conditioning system alone cannot control humidity in a home year-round, because there are many days each year when it's not in use.

"We have nighttime, mornings, winter days, cloudy days, rainy days; so many days where the air conditioner isn't going to run unless you turn the thermostat down," says Mooney. "But cranking the thermostat down in my part of the country turns the house into an evaporator coil, and you create indoor air quality problems."

The overcooling by the homeowner because they are not comfortable with the high humidity level in the home brings the whole house temperature down below the dew point. This can cause interior wall spaces to sweat, and develop water and mold problems. Running the house that cold can also cause equipment, ductwork, and supply registers to sweat.

Once CCAC's customers have control of the humidity in their homes, they tend to turn their thermostats up to 76 or 78 degrees and feel much more comfortable than they did before at 68 to 70. The energy savings of turning the thermostat up, in most cases, more than pays for the energy used by the dehumidifiers.

Aaron York, Sr., president of Climate Engineering, Indianapolis, IN, is in his 55th year as an HVAC professional. He's seen a tremendous number of HVAC firsts, but can't wait for what's next.

"Years ago, heat pumps featured a timed defrost system. Today, we've advanced to 'demand defrost,' which says we will test before defrosting. If we don't need to, we won't waste the energy.

"That's what's happening with the controls we have today: we're determining need and making the equipment meet that need exactly."

Other Examples of Advanced HVAC

Controls Invensys Climate Controls' new series of Robertshaw® programmable thermostats combine humidification and dehumidification control into one unit that is easy to program and install. These thermostats adjust indoor humidity levels automatically when coupled to an optional outdoor sensor.

Bryant's Evolution™ System control features straightforward prompts, PerfectHumidity®, and controls for air quality, fan speed, and ventilation. Also features day-at-a-glance, 7-day programming and an optional Remote Access Kit.

The Lennox SignatureStat™ Home Comfort Control works with advanced heating and cooling systems to regulate moisture levels and temperature inside the home, and is designed to control the exclusive Humiditrol® whole-home dehumidifier system, shown at right.

The York® Total Comfort System from York — a Johnson Controls company — includes air-to-air exchangers which replace a portion of stale indoor air with fresh outdoor air at reduced energy cost. Ultraviolet air treatment systems prevent mold spore growth on air conditioning coils, and electronic and media air cleaners remove up to 94% of particles 0.5 microns or larger from the air that passes through the home comfort system.

Emerson Climate Technologies — a business of Emerson — has added a universal staging model to its White-Rodgers division's line of 90Series™ Blue™ touchscreen thermostats. The 1F95-1271 works on single-stage, multi-stage and heat-pump applications without the need for additional wiring.
About the Author

Terry McIver | Content Director - CB

A career publishing professional, Terence 'Terry' McIver has served three diverse industry publications in varying degrees of responsibility since 1987, and worked in marketing communications for a major U.S. corporation.He joined the staff of Contracting Business magazine in April 2005.

As director of content for Contracting Business, he produces daily content and feature articles for CB's 38,000 print subscribers and many more Internet visitors. He has written hundreds, if not two or three, pieces of news, features and contractor profile articles for CB's audience of quality HVACR contractors. He can also be found covering HVACR industry events or visiting with manufacturers and contractors. He also has significant experience in trade show planning.