About twenty years ago, my sister lived in apartment. Shared the
second floor of a rental house. The other tenant had the thermostat.
He'd turn it way down, and go to work. She and her boyfriend would
freeze butt all day.
Earl Proulx has done something similar. The "Yankee home handyman". He
has put a non functioning stat for the old folks to fiddle.
Begining to sound as like you all assume I'm not to swift. Let me give
you 1 of many reasons I don't care for the decision process of the
thermostat using it's default settings.
Had therm set overnight at 68. Next morning the outdoor temp was ~ 55.
Reset therm to 74. 2nd stage HP heat came on and was doing a reasonalbe job
bringing up the indoor temp. At some point therm decided to it was taking
too long and switched to gas heat. At that outdoor temp and with the gas
vs electric rates in my situation, the gas heat was ~ 5X as expensive as HP
heat. I've since disabled the time-out timer that mindlessly switched to
gas. Now the only time it will auto switch to gas is if the outdoor balance
point is reached or if I decide I'm willing to pay higher month cost to more
quickly reach the indoor set point.
I'm a professional engineer who understands this stuff. In my old system I
just put a toggle swich on W2, but there's no W2 (or W1, Y1, or Y2)on
these data-link systems so I need to learn this new (to me) config
Hope this helps understand where I'm coming from.
I now understand what it is you want to do and why. The only problem
is that you no longer have a simple relay logic control system. The
only thing to do is hack the system or discover the insider secrets
to programming your gear which may only be available to dealers and
company engineers. I wonder, does your system have any kind of remote
communication capability? When me and an electrical engineer friend
were installing HVAC control systems in some new schools some years
ago, the systems were tied together to a central point and accessed
remotely via a dial up modem. A system as modern as what you have
must surely have an Ethernet connection somewhere or at least a serial
Perhaps if you could rig a computer interface, you could write your
own control software. I have no idea what communication protocols
your system is using. Heck, it all used to be RS232, 422, 485 and
a few other serial types. Now there's some stuff I've never seen
and have no clue as to how it works. I think what you would really
like is a smart home interface with your HVAC system. I would be a
lot of fun to pull it up on the computer and control it in real time.
The 'auto discovery mode' on these new systems is like 'plug & play' on a
PC. While most installers are content to let the system set itself up, the
installer manual actually allows quite a few configuration parameters that
can be set in the 'installer mode'. For now I'm content to just figure out
what they all mean, which is what lead to the "Compressor Cycles Per Hour"
question. Choice is 2-6 (default is 3) Most likely it means what it says
but what is the 'intent' of the setting. It's a new term to me.
I haven't installed any systems like what you have because me and my
buddy don't have a customer base that can afford the latest super
duper with all the bells and whistles systems. The closest I come to
complicated controls is in the mini split systems. We have a friend
who is a Standard and Trane dealer and I'm sure he has sold brainy
systems like yours but he's not going to play with the parameters
unless he's on the phone with the factory tech support.
I'm going to make a SWAG that the CCPH will also affect compressor
run time in a way that the system will overshoot the cut off set
point more with the fewer number of compressor cycles. It's similar
to what I do on refrigeration mechanical control systems using
pressure switches. I'll set a wide differential for cut in and cut
out to keep the compressor from cycling too often. The existence of
product provides the needed hysteresis for the control cycle. It's
what I often describe to people as a thermal flywheel to help them
understand. Folks will turn the thermostat way up or down depending
on the season thinking it's going to change the temperature inside
their home faster. I tell them that the little lever is not like an
accelerator peddle in a car and the HVAC system only has one speed
(except for multi-stage) and it's not going to work any faster. I
know there are new systems for homes that have variable speed drives
for both compressor and air handling but those aren't the majority
of systems in existence. In the future the whole dang house will be
controlled by a computer but most of us will be gone by then and won't
have to worry about it. You could even program the house loud speakers
to blast out "YOU KIDS GET OFF MY LAWN!"
So your telling us that it wasn't set up correctly in the first place.
The *ONLY* times the furnace should light off is when the balance point is
reached, or the control is put into emergency heat mode. There is a
propriatary cable and propriatary software (its not free) to be able to
interigate and configure serial controled systems from a laptop.
FWIW, I don't even have it... At this time, its not worth it for me to buy
the software and cable.
If you toggle on the intellegent recovery function, the control will use the
most economical means of bringing the home from night time setback up to the
daytime setpoint. The control is constantly learning when to bring the
system on and in what mode to have your home at the desired setpoint at the
desired time. Its going to do a whole lot differently at 55F than it will at
25F, but its going to do it in the most economical means possible.
You can also toggle the setting for comfort or economical...this will help
Do the high end systems you sell have remote management capability? I
see it with a lot of other stuff I deal with but haven't worked with
any home HVAC systems that have it. Remote management has become so
inexpensive as of late that it's easy to add to just about anything.
Heck, I think there has been an Internet ready refrigerator around
for a while. I seem to recall seeing some IP addressable thermostats
available but I haven't played with any, yet.
I don't have the remote management capabilities with the system I install
(yet), but all of the systems I install either have the VP-8000 control, or
the IAQ control for dual fuel/hybrid systems. Even though the IAQ control
has "auto-discovery", I choose to do it manually, as well as to spend the
10 - 15 minutes to do the setup and programming when I install them, as
well as programming the customers comfort settings. But you gotta remember
that I do things differently than "Bubba" or "Billy-Joe-Jim-Bob".
I figure I must be doing something right, 15 years and I am *still* in
business(and making a profit), with a customer base of over 600(18% have
service agreements).... not too bad for a one man band in rural, small town
Congratulations on your success, I wish my health was better so I could
take care of more people. I'm glad to hear that you take the time to do
it right the first time. It's a shame more folks don't have the same
work ethic and just throw the equipment in. I'm sure you come across a
lot of situations that elicit a big WTF and the question of why on earth
did those guys do that? Keep up the good work! 8-)
Steve - I also would have expected that the *ONLY* times the furnace should
light off is when the balance point is reached but it's not so. There's a
theremostat parameter called Installer Setup Number (ISU) 0346. It's labled
"Dual Fuel Heat Pump Upstage to Furnace Timer". The installer manual
describes it as "System will switch to gas furnace to satisfy call for heat
if timer expires" Factory default is 60 minutes. Since I disabled it, it
stop switching over to gas.
I hope this helps clarify why it's in my best economic interest to better
understand and take some control of the beast.
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