Infinity Control

[perel]

As I've been looking at replacement (heat pump) HVAC systems, I keep coming back to the Infinity system with Infinity control. I know it's generally bad to pick equipment first, though, so I'd like to figure out what other systems would work well for me. What other systems out there are similar in terms of comfort, control, and zoning capability?

I would ultimately like to also have some integration (possibly just setpoint override) with a whole-house home automation system. My understanding is that it *is* possible to interface with the Infinity control, but the command set is undocumented. Anyone successfully done this sort of integration?

Also, I understand that the Evolution system is the same thing as the Infinity. Other than that, though, is there anything else I should be looking at?

[smadave]

I have installed quite a few infinity heat pumps this year and I will tell you that this stuff is incredible. I cant say enough good things about the infinity technology and it really shines with the heat pumps. The only thing I do not like about it is the marketing. Carrier will lead you to believe that you acheving 17 SEER but you will most likely be around 14 SEER. I havent interfaced with a home automation system yet but I know you can hook it up to your computer or phone where for a few dollars a month, you can access your system from remote locations. I can even troubleshoot your equipment from my house via my computer. Living in NJ, I use to cringe whenever someone wanted a heatpump, now I am excited.

Dave in NJ

[wyounger]

For heating comfort with a heat pump, other high-end systems can nearly match what the Infinity systems do. The important strategies in this realm are slowing down the blower speed when outdoor temperatures get very cold (to keep the output air warm enough that it doesn't feel drafty) and using multistage heat strips, controlled by a thermostat that stages the heat strips. Simpler systems tend to have fewer (or just one) stages to their heat strips, and they have to cycle the full power on and off to maintain a given temperature. The output air tends to feel hot-cold-hot-cold at that point. With multistage elements, you can run a low wattage for long periods and have a steady and moderate discharge air temperature. No drafty feel that way. I wish Carrier would start using demand defrost controls on their heat pumps, though, instead of the old time-temp system.

For cooling comfort in climates where humidity control is an issue, other systems can almost do everything Infinity systems can do. Again, the Infinity just has more flexibility in its control strategies. Competing systems may have a regular cooling mode and a cooling with extra-dehumidification mode; Infinity can move smoothly between those two priorities with no distinct step between them. Infinity, like Carrier's Thermidistat, considers room temperature and humidity together in working towards a comfortable indoor environment; other systems that pay attention to humidity tend to treat temperature and humidity as separate issues and ignore how humidity affects our perception of temperature.

Infinity systems can integrate control of system accessories (humidifier, air cleaners, UV lamps, etc.) about the same as other top-end control systems. The only thing they've really added is the ability to monitor actual filter restriction from the thermostat, without an extra (separate) box on the wall. So you can change the filter when it actually needs to be changed, instead of based on some pat assumption about how many days it will take before the filter gets too restricted.

Infinity zoning is a full generation ahead of anything else, though. To me, that's what would really push me to decide up-front. Owning an Infinity system, I can see that the other brands can match most of the other features with their competing top-end equipment, except for the way that the zoning works.

The major differences in the zoning are that
-the zone dampers (the flow gates that control where the zone system is sending air to) are variable position instead of open-or-closed
-the system measures the airflow capacity of the ductwork for each zone and coordinates its operation strategies for making each zone comfortable. If one zone can't handle the full airflow but really needs some conditioning, and another zone could benefit from some conditioning but doesn't really need it, the system will send all of the airflow it can to the first zone and the excess to the second. Other zoning systems can sometimes be set to do this ("dump zone") but they do so blindly, so you usually just set the system to dump any excess air into the basement and don't try to closely control the temperature down there. Infinity can choose one or more dump zones on the fly based on current conditions, without overconditioning any one zone.
-the system knows the temperature in every zone at all times (not just if the zone thermostat is calling for heating, cooling, or is satisfied), so it can coordinate the demands of the different zones. Instead of cooling one zone for 5 minutes (WHOOOOSH), shutting off, and then starting up 5 minutes later to provide 5 minutes of cooling to a different zone (WHOOOOSH), Infinity knows that both zones will need some cooling soon. When it starts up in cooling mode, it sends the right amount of cool air to each zone so that they will be satisfied at about the same time. Since the airflow is split between the zones, you're not trying to send full airflow to a single zone at once so much.
-you can stand at a single control panel but see the temp in all of the zones, and adjust the setpoints for each zone (or all zones at once) from that single control panel. You don't have to GO to a zone to check on it or adjust its settings.
-by understanding equipment staging, the amount of conditioning demanded in all of the zones (at all times), and keeping tabs on duct capacity, they can also do a better job of coordinating equipment staging (ie high or low heat/cool) with the needs of the structure

The actual user interface is pretty cool, too, though the industry is working fast to close that gap (the VisionPro thermostat is a good example). The ability of the indoor/outdoor/zoning equipment to send status and trouble code information directly to the thermostat display is really nice, too, even in the absence of home automation/remote diagnostics/etc. For example about a month ago I did actually have a board failure in my Infinity furnace. When I called my contractor to have them come out to fix it, I gave them the trouble code over the phone, and they felt confident enough about what that meant that they actually went and got a replacement board before coming. That saved us both the usual 5 pm "hmm, it must be the board, I don't have those on the truck, let me go get one and I'll be back with it in the morning" deal. They came and handled it in a single visit.

I know nothing about the home automation integration, except that Carrier is aware of the interest and has been working on it.

[Edited by wyounger on 12-09-2005 at 05:51 PM]

[hvac hero]

Wyounger, they oughta give you credit for about 5 posts for a post that long. LOL

[airworx]

just a remark about the carrier says 17 but only gets 14.
mostly they get 15 to 16, but thats the norm. every manufatures rates unit but most systems rated above 14 usually will nor or cannot achieve it. these systems are generally rated with a small unit size say 2 ton matched with a larger coil size say 5 ton.
saying this you really have to match the system and get the seer rating for that match.
looking at the eer is the more reliable source anyway.