Climate Control Over the Internet: Carrier Infinity System Access Module
Program your thermostats, control system with Web-based interface
By Charlie White
Infinity is the name Carrier gave to its highest-end heating, air conditioning and ventilation system that precisely controls temperature, humidity and fresh air ventilation throughout the house. All this climate control accuracy can be controlled via the Internet, too. Since we already had a four-zone Carrier Infinity heating, ventilation and air conditioning (HVAC) system installed here at our Midwest Test Facility, we were able to evaluate Carrier's optional Systems Access Module, allowing you to access the climate control system's functions via telephone or the Internet.
To install a complete Carrier Infinity HVAC system could cost between $10,000 and $15,000, but to install just the Systems Access Module, along with the special dampers and zoning control module it requires is about $3000 installed. This remote access system, first rolled out in early 2005, also requires Carrier's Infinity furnace and air conditioning system (pictured at left).
This type of remote climate control is popular with people who own vacation homes, letting them remotely program the temperatures in all the zones of their vacation homes from a computer, telephone, or cell phone. It's also convenient to be able to control the temperature in the house if, for example, you're required to work late at the office, and would like to save some energy by delaying the climate control system's temperature adjustments until you get home. The System Access Module will let you call your HVAC system on your cell phone and have it warmed up for you by the time you arrive.
|The System Access Module with its cover on and then off. Its antenna allows communications via the SkyTel pager network.|
Our test System Access Module (pictured above) contains a radio that connects to the SkyTel pager network, and from there, it communicates with the Internet. There's an annual fee of $100 to subscribe to the SkyTel pager network to enable this unit to work. The module took considerable skill and expertise to install, and uses a signal finder that didn't require it to be connected to the Systems Control Unit to indicate a signal had been acquired. Carrier technician Paul Scott was able to position the radio in just the right spot in our facility to dependably receive its radio signals.
Also part of the Carrier Infinity system is an aesthetically-pleasing four-wire two-way communicating thermostats designed by IDEO, the design firm that created the first Apple mouse. The units, especially the master thermostat, are simply the best-looking HVAC controls we've seen. The master unit is exceptionally easy to use and has a backlit LCD screen with a backlit display that can be set in an always-on low-intensity mode that can be easily seen at night, or shut off entirely in case the unit is used in a bedroom. The system uses at least one of these master thermostats on which you can program all the functions of the system, and other smaller, simplified thermostats that are distributed through the other zones in the house.
The Systems Access Module is also equipped with an RS-232 port that provides a gateway to home automation systems with its open ASCII communications protocol. Carrier told us its system is compatible with home control products from Crestron, and other home automation manufacturers such as HomeLogic and AMX are actively working on versions that will also be compatible.
The control of the scheduling and temperature parameters of the system can be done from the master thermostat, remotely from a Web-based interface, or over the telephone. Once the account is set up and you've paid the $100 annual subscription fee, the interface indicates that it has begun communicating with the Systems Access Module via the SkyTel network. Carrier says the reason its designers opted to control the system via this radio network was because it's easier for installers who aren't necessarily computer savvy to work with, and also because it didn't require a computer network to operate. Carrier told us it was working on Phase 2 version of the system with a WiFi and Ethernet-based System Access Module that would be released mid-2007.
|The Infinity thermostat is easy to use and lets you control up to eight zones from one location. Here Carrier technician Paul Scott is configuring the thermostat for the four zones of the Midwest Test Facility..|
So what's it like to use this remotely-accessible HVAC system? At first I was amused by the novelty of the system, enabling me to control the temperature of all four zones of the Midwest Test Facility from any location where I had an Internet connection. A system like this even has exceptional prank value. For instance, on a recent trip to New York, I played a trick on my assistant by raising the temperature in her office by 5° for one hour at a particular time of the day, much to her confusion and ultimate amusement.
It takes about three minutes to establish communication with the systems access module. That's the system's only drawback -- its slow communication between the Internet, the SkyTel pager network and the Systems Access Module can be frustrating. It became especially cumbersome when I wanted to retrieve the current settings from the system, which required a wait of three or four minutes. Carrier says its upcoming Ethernet-based System Access Module will eliminate that drawback, and will have instant response.
On the Internet interface, you're able to control everything you can set on the master thermostat unit except for the humidity parameters and the thermostat's backlighting. You're able to specify temperatures for heating and cooling for four different times of the day, and you can control that in up to eight zones. The interface smartly lets you use the same Web settings that you used before, not requiring you to wait that three or four minutes to retrieve your system's current settings. That's a nice touch, because rarely do you need to retrieve your current settings unless you've made changes to the master thermostat. But I've found that it's easier (and more fun) to control the system via the Web, turning that fancy thermostat and its three siblings into curiously interesting and well-designed backlit wall decorations.
|After logging in, this screen indicates the status of the system, and the satellite icon on the right with the red dots shows that it has initiated communication with teh SkyTel pager network.|
|This screen allows you to save time by selecting "Modify Last Web Schedule," avoiding that three-minute wait to retrieve the current schedule.|
|Here's where you remotely program your thermostat for each zone in your system, after which you send these commands to your home via the SkyTel network.|
You're also able to immediately control the current settings of the HVAC system, adjusting fan speeds for individual zones (from a whisper-quiet Low to powerful High) or setting each zone to hold a constant temperature. Once you've made an adjustment to your system, it notifies you via e-mail that changes have been made. Just like the computer HAL from the movie 2001: A Space Odyssey, the system is also able to notify you (and also your Carrier dealer, if you wish) if there is something wrong with the system, when the filter needs to be changed, or when it's time for service. It's even able to measure the air pressure of the various zones and your system overall, determining whether you need to change a filter.
|This graph shows how accurately the Infinity HVAC system can hit and hold temperatures. The thermostat for this zone was set at 69 degrees until 8pm, 70 degrees at 9pm, 68 degrees at 10pm and 64 degrees at 12:30am. The Energy Star-certified Midwest Test Facility is well-insulated, taking nearly six hours to fall five degrees when it was 10 degrees outside.|
Using the system in a daily routine proved that this is a remarkably accurate system for controlling temperature throughout the house (see zone graph above). This heating, air-conditioning and ventilation system is able to bring the temperature of the various zones to less than a half a degree of what we specified, and keeps the temperature there with surprising accuracy. It's also able to completely ventilate the house, changing the air eight times during each 24-hour period using a highly efficient energy recovery ventilator (ERV), which is able to bring in fresh air from the outside but heat it using the warmth from the air being exhausted out, and vice versa in the summertime.
Summing up, Carrier's System Control Module works exactly as advertised, and has responded perfectly to every command we've given it over the past couple of months. It dutifully makes changes and flawlessly sends its data from the Internet across the SkyTel network and to our HVAC system. Beyond that, the Carrier Infinity system is the quietest and most accurate climate control system we've ever seen, and incorporates the highest technology as well as exceptional control expandability. Highly recommended. 8.9 out of 10 stars.