Remember, I was telling you not to turn them on?
Well, now they've been caught in action - take a look (clickable):
So here cometh a fresh pair of thermostats (Honeywell RTH7500 and RiteTemp GPMG8085C), both equipped with default schedules taken from EnergyStar ® Program Requirements for Programmable Thermostats: Partner Commitments (look for Table 2: Acceptable Setpoint Times and Temperature Settings). It was summer, and the default settings were too cold for us, so we changed them.
But the defaults for the heating season were left in place.
Now that the heating season is here, and it is eventually getting quite cold outside, several interesting things are popping up.
First of all, let's take a look at default EPA compliant settings.
Wake: 6AM, 70°F.
Day: 8AM, 62°F.
Evening: 6PM, 70°F.
Sleep: 10PM, 62°F.
Then, let's go back and read the long rant about whether you should shut off your A/C or leave it running.
Then, let's take a look at the temperature spread for the schedule above. 8°F.
That's quite a lot.
The very reason I've started thinking about writing this article is that one of my units (Lennox split), being perfectly capable in cooling mode, seems to either hit the balance point, or otherwise severely degrade its performance, when the ambient temperature drops lower than about 45°F - and, as a result, it is unable to bring the zone it serves from 62°F to 70°F in two hours.
Even worse the temperature actually drops to about 65°F by 6AM, and it barely makes it to 68°F by 8AM - forget 62 to 70.
While this is definitely quite uncool, it also points out another fact that is not on the surface: the unit works at the top of its efficiency curve. It doesn't cycle, it spends initial 10-20 minutes approaching the design efficiency and stays there.
That was the positive, now, another negative - since it serves two rooms, one of which is about five times size the other - guess what, by the end of the two hour run the smaller room is HOT. Balancing the dampers manually will not help since it'll shoot the balance for other conditions - like, the evening, when the ambient temperature is significantly higher and the runtime of the unit is very short in comparison.
So, what's the point?
I've been pondering about this question for a long, long time - starting in about 2001 when the only way to control DZ available was a debug panel, and last time in an essay about SWMBO Compliance Certification (Squeezebox is still a good candidate), but it seems that there's been a new development that might if not put an end to the fruitless search, then significantly widen the options available.
I'm talking about Android.
It remains to be seen how viable the platform is and how many hardware manufactures will jump on the bandwagon. But for now - having worked on different Google APIs (Checkout and Calendar in particular) I can say that it's sure going to be a hell of a fun ride, and I'm about to get busy installing the Android SDK and tinkering with it to see how well can a user interface for a HVAC system work on a cell phone.
Now, who needs a thermostat on the wall, really?
Good judgment comes out of experience. Experience comes out of bad judgment.
It seems pretty obvious in hindsight, but somehow didn't come to my head that I might have problems running fish tape through a rigid plastic conduit with a few bends. Guess it is not usually a problem, otherwise it would be widely documented - or it may have been just my dumb luck, but...
Turned out that a wide and big 1" conduit run of 26ft with two 90° bends is not passable in either direction.
Took me a split second to realize why - the bell. The one that is at one end of each conduit component. The rest should be obvious.
Two conclusions:
Talk about outsmarting oneself.
The whole point of The Dual Nightmare article was to convince the reader that there's no way two HVAC units can serve the house as good as one zoning system. Alas, the subject didn't click together with what people were looking for. Let's see if this one is better.
Exactly where you put it, dummy.
Correction: I am the dummy.
So here I am, trying to figure out the way to configure the hysteresis and, at the same time, save myself a long walk to the shelf at the second floor where I *think* I put the plastic bag with the manual and spare parts. Also, it's middle of the night, it's dark, the light switch is out of the way, everyone in the house is asleep and I don't want to step on the cat strategically placed somewhere down my path.
So I'm thinking: it's 2007, let's google it up.
Yeah, right.
I guess my patience is thinned by previous encounters with HVAC machinery and service, unlike one of this gentleman.
Mind you, all configuration settings in this thermostat are not described by words. They are described by numbers. There's no way in hell I can remember numbers I have to use once in a few months, if not years. And the paper manual is nowhere to be found. And what other companies usually put up (a printable PDF document) is nowhere to be found, either.
Nice.
Another score for Rite Temp.
And don't lose your manual, otherwise you end up with a quite expensive brick on your wall.
Update: I've found the manual...
Who would've thought that this blog would be one of the most often referred to sources of information about GPMG8085C... All right, if that's what y'all want...
Ever heard of "The Golden Triangle"? "Good, Cheap, Fast - Pick Two". So, this thermostat may just as well be the closest approximation. $20 cheaper than the next guy (Honeywell RTH7500, I'll come back to it another time), does the same job, if not better.
Comparable quality and length of DIY installation.
Installation complexity: no-brainer (YMMV). A few advices, though:
Someone who's been through one major and one minor flood, heat pump compressor, four or five pool pump motors, couple of pool filter tanks, few dead refrigerators is not likely to treat warranty issues lightly. Thus, after being somewhat dissatisfied with service contractors taking a bit too long (up to three-four days) to show up, I decided to abandon my warranty company in favor of @#$%S, a big, domestically owned, reputable company. There is safety in numbers, I thought.
How naive of me.
Jumping ahead, I did go to extreme depths to explain to them that I have not one, not even two, but three units and did have to pay extra premium for the service.
Being diligent, I decided to use the service that's been advertised among other warranty clauses - preventive maintenance. So I call them up, they give me a window a couple of weeks later, it's still February, I'm thinking, what could go wrong...
Right.
Guys show up, take a look at the unit, say it's not on their record, spend half an hour on the phone with headquarters, say this unit is not on their records. I say fine, there's another one, which is on your records, go take care of that. They do, profusely apologize, and leave. I call up again and explain that the unit in question is not quite up to snuff and has to be looked up, they say sure, and schedule another appointment two weeks later.
No call, no show. With a window like 9 to 12 or 1 to 5, it's quite aggravating - half a day is wasted.
Another call, another two weeks. A crew arrives with gusto, steps up to the unit and says "Dude! This unit is not on our records!" as I stare at them in disbelief. So I make them write down the model and serial numbers of all HVAC equipment, upon completion of which task they notify me that I have not three, but five units, namely, one rooftop, two condensers and two air handlers. Fine, as long as the unit gets taken care of. They say they can't do anything now without headquarters approving, and leave.
Another hour on hold, another conversation, another two weeks. Another crew arrives. Guess what? The unit is still not on records.
Another hour on hold, another conversation, another two weeks. Another no call, no show.
I'm thinking, it's costing me too much aggravation already, the hell with it - if it breaks, they'll fix it. So I leave it alone.
So the summer comes. In June, one of my HVAC units goes dead (the one @#$%S "maintained"). I call @#$%S, they say it'll take them 9 (nine) days for them to dispatch the serviceman. I tell them this is unacceptable, keep biting their ankles every day - and 8 days later, the guy shows up. Replaces the fuse and is on his way. Not that I would believe that the fuse is the root cause, but there's nothing I can do with it - all in all, he's a professional...
Within two weeks, the unit is dead again, with the same symptoms. To make the long story short, it took them over a week to send someone over (mind you, we're talking about August in Phoenix), and the unit did get fixed. Ground short.
This is not a kind of service one pays premium for, so BBB complaint gets filed, processed, and somewhere in the middle of the winter a symbolic compensation comes. End of story.
Or so I thought.
What made me dig up this stinking corpse is that an appliance I bought a while ago, it turns out, has its warranty served by @#$%S. Damn, I say, let's hope it works this time.
Yeah, right.
Scheduled visit number one, 1 to 5 window. No call, no show. At 4:30 service center is called, and they are telling me that the contractor is actually parked in front of my house. Right. At 5:30 another call to service center, and they're told about the fact that contractor never made it in from the driveway, about pretty contemptible track record, of preexisting BBB complaint. They politely apologize and say they will have to call back reschedule.
A day passes. No call. Calling them. Another hold, another conversation, another 1 to 5 service window. Another no call, no show.
I wonder, are they brain dead? Okay, it may be fine to screw things up once. Not so okay, but happens twice in a row. But six??? And a complaint??? And, after that, two times in a row again?
Now, for those curious about the actual identity of the company... Pretty easy to figure out - I just want to leave myself some maneuvering space in case they ever get to read this and decide to send me a cease and desist. That would be fun to watch, though, and something tells me that I'm not the only one having this kind of experience. And have no doubts, another BBB complaint is on the way.
The most saddening thought? They're not alone. This winter, the unit I was trying to take care of in this story has finally died (pretty non-trivial failure, as it eventually turned out), and the contractor that was trying to fix it tried everything he could think of (took couple of weeks to order the parts, have them delivered, and another appointment scheduled), then just "recharged" the unit and said "Let's pray that it keeps working".
I guess he wasn't praying hard enough. But that's a different story for a different time.
Weighting the priorities is the most delicate task there is.
On one side, you have a bunch of unhappy people, some of them complaining of being hot, some of being cold.
On the other hand, you have The Other Decision Maker which notifies you in no ambiguous terms that those blue wires on that ivory wall (beautiful combination, if you ask me) won't be tolerated. At least no longer than a week. Or a month. Or a year. Or two.
Depending on how well and how fast you can silence the unhappy gang. You do it fast, you're forgiven.
Until the time when you're not home, but Someone Very Important feels a need to change the setpoint. Right there and then.
Which brings you to the point of explaining that you have to take that remote, press this button five times, that button three times, then... wait, you've just run out of their attention span - one of the kids fell into the pool.
So much for advanced user interfaces.
I'm still toying with the idea to use my Squeezebox, along with a SlimServer plugin, say, xAP for SlimDevices, but by now it is painfully clear that the only person who would be able to ever use that interface, and/or willing to use it, would be me. Though scratch that, I'd probably go directly to web interface. More about that later.
So apparently the Honeywell Round® is still the best thing since sliced bread. Granted, the mechanical one had a drawback that caused the worst kind of thermostat wars: one could swing it all the way up or down in one swift motion, and people on both extremities of the age span could have trouble applying controls in moderation - but it was cheap and simple.
And, no matter how badly does a digital thermostat in a round body freaks you out, there are decades of usability research behind it. It solves the task at hand perfectly.
Until you run into something as simple as a heating/cooling schedule. Which shatters your interaction model completely. Not even talking about zoning.
Now, you either have to add more buttons (left), or use soft keys (right). The former solution makes the design more expensive and less durable, the latter makes ergonomics more complicated (but at the same time, more flexible).
In other words, you probably can't get the best of both worlds (simplicity and flexibility) in one package, a compromise is required. Most sensible compromise seems to be in a form of arbitrarily complicated master panel that one has to spend a week programming, and a very few critical functions and overrides exposed to the end user.
To be continued...
Reading digg, stumbled upon set of Tricks to Keep Your House Cool this Summer. Immediately remembered a non-trivial observation I made in my old house: amount of heat produced by a stock ceiling fan, or a few desk fans, can easily overcome the subjective drop in temperature caused by increased air circulation (the temperature rise was actually measured, it is not a guess).
This is not necessarily always the case - the smaller the room, the more pronounced is the effect. Or, should I say, the easier it is to measure it...
Original observation is a part of the DZ article called Hot Summer of 2003.
Another argument worth repeating - any heat producing device in your house (fans included) makes your A/C work harder, so not only you're not improving situation, you're making it worse.
