Programmable Thermostat with Ramp

[Rick C]

I am using a programmable thermostat to turn off the heat and/or air conditioning during the peak usage times as set by the ToU billing with my utility. The problem I have is the heat pump not ramping up the temperature fast enough when it comes back on and the backup straight electric heat coming on. This uses maybe three times the amount of electricity during the time it takes to get up to temperature.

I don't know if this is caused by the thermostat or the heat pump itself. I'm wondering if anyone makes a programmable thermostat that deals with this issue. If the problem is caused by the thermostat not letting the heat pump run long enough that is easy to fix. If the problem is caused by the heat pump itself, then the way to deal with it is for the thermostat to run the heat pump in bursts short enough to keep the back up heat from running.

Anyone familiar with this? Consumer Reports doesn't mention this in a quick look at a few thermostats. The do list "Early recovery" which turns on the heat/cooling ahead of the set time so the home is at the right temperature when you arrive (rather pointless in my opinion since I can just set the time early if that is what I wanted.)

They are starting to address the ToU billing issue in EV charging. Any sign of this in home heating/cooling?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Winfield Hill]

Rick C wrote...
>
My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.


--
Thanks,
- Win

 

[Whoey Louie]

On Friday, January 10, 2020 at 10:54:48 PM UTC-5, Rick C wrote:

I am using a programmable thermostat to turn off the heat and/or air conditioning during the peak usage times as set by the ToU billing with my utility. The problem I have is the heat pump not ramping up the temperature fast enough when it comes back on and the backup straight electric heat coming on. This uses maybe three times the amount of electricity during the time it takes to get up to temperature.

I don't know if this is caused by the thermostat or the heat pump itself. I'm wondering if anyone makes a programmable thermostat that deals with this issue. If the problem is caused by the thermostat not letting the heat pump run long enough that is easy to fix. If the problem is caused by the heat pump itself, then the way to deal with it is for the thermostat to run the heat pump in bursts short enough to keep the back up heat from running.

Anyone familiar with this? Consumer Reports doesn't mention this in a quick look at a few thermostats. The do list "Early recovery" which turns on the heat/cooling ahead of the set time so the home is at the right temperature when you arrive (rather pointless in my opinion since I can just set the time early if that is what I wanted.)

They are starting to address the ToU billing issue in EV charging. Any sign of this in home heating/cooling?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

Honeywell VisionPro Series has adaptive recovery. You set the time and
temp for what you want it to actually be and for recovery after setback
it then figures out what time to fire it up to get it there. And it learns..
It works excellent with the gas furnace here and it supports heat pumps,
so I would expect it will work the same with those. IDK what algorithm
they use, but obviously it's based on how big the delta is that it has
to close and how fast the thermostat knows it takes to raise the temp one
degree. Besides that, I would think it may factor in how fast the temp
has dropped while in setback, to get some gauge as to how cold it is
outside, to further refine the calculation. It always makes it to the
desired temp by the desired time.

 

[Rick C]

On Saturday, January 11, 2020 at 8:49:50 AM UTC-5, Winfield Hill wrote:

Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

Yes, you have posted about the limitations of your heatpump before. How is that relevant?

I suspect if you check with someone who knows, your backup heat will also run under two other conditions. One is the system detects ice on the outside coils. With a 40 degree cut off, your system might not worry with deicing. The other condition is when the system runs long enough that it decides the heat pump is not doing the job and switches to backup heat. Opps, another condition is if the inside temperature drops too far bellow the set temperature.

The first heat pump I owned was very, very simple. It had a two bulb thermostat. Set the temperature and bulb 1 would control the heat to keep the temperature. But if the room (hallway as the case may be) temperature dropped too far the second bulb switch would close and the backup heat would come on.

That is the condition I am trying to avoid with a thermostat which ramps the temperature up slowly enough to not kick in the backup heat.

I don't know of any heat pump that isn't set to work that way. Ask your installer. With the last system I bought I found I could not even get info from the company who made it. They always referred me to the "installer", like I was not worthy of information.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Rick C]

On Saturday, January 11, 2020 at 11:12:33 AM UTC-5, Whoey Louie wrote:

On Friday, January 10, 2020 at 10:54:48 PM UTC-5, Rick C wrote:
I am using a programmable thermostat to turn off the heat and/or air conditioning during the peak usage times as set by the ToU billing with my utility. The problem I have is the heat pump not ramping up the temperature fast enough when it comes back on and the backup straight electric heat coming on. This uses maybe three times the amount of electricity during the time it takes to get up to temperature.

I don't know if this is caused by the thermostat or the heat pump itself. I'm wondering if anyone makes a programmable thermostat that deals with this issue. If the problem is caused by the thermostat not letting the heat pump run long enough that is easy to fix. If the problem is caused by the heat pump itself, then the way to deal with it is for the thermostat to run the heat pump in bursts short enough to keep the back up heat from running.

Anyone familiar with this? Consumer Reports doesn't mention this in a quick look at a few thermostats. The do list "Early recovery" which turns on the heat/cooling ahead of the set time so the home is at the right temperature when you arrive (rather pointless in my opinion since I can just set the time early if that is what I wanted.)

They are starting to address the ToU billing issue in EV charging. Any sign of this in home heating/cooling?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

Honeywell VisionPro Series has adaptive recovery. You set the time and
temp for what you want it to actually be and for recovery after setback
it then figures out what time to fire it up to get it there. And it learns.

That is exactly wrong for my situation. I mentioned that in my first post. Another company calls it "Early recovery".

It works excellent with the gas furnace here and it supports heat pumps,
so I would expect it will work the same with those. IDK what algorithm
they use, but obviously it's based on how big the delta is that it has
to close and how fast the thermostat knows it takes to raise the temp one
degree. Besides that, I would think it may factor in how fast the temp
has dropped while in setback, to get some gauge as to how cold it is
outside, to further refine the calculation. It always makes it to the
desired temp by the desired time.

Yeah, that sounds like it works well, but it's a great solution to the wrong problem.

--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209

 

[Whoey Louie]

On Saturday, January 11, 2020 at 12:07:33 PM UTC-5, Rick C wrote:

On Saturday, January 11, 2020 at 11:12:33 AM UTC-5, Whoey Louie wrote:
On Friday, January 10, 2020 at 10:54:48 PM UTC-5, Rick C wrote:
I am using a programmable thermostat to turn off the heat and/or air conditioning during the peak usage times as set by the ToU billing with my utility. The problem I have is the heat pump not ramping up the temperature fast enough when it comes back on and the backup straight electric heat coming on. This uses maybe three times the amount of electricity during the time it takes to get up to temperature.

I don't know if this is caused by the thermostat or the heat pump itself. I'm wondering if anyone makes a programmable thermostat that deals with this issue. If the problem is caused by the thermostat not letting the heat pump run long enough that is easy to fix. If the problem is caused by the heat pump itself, then the way to deal with it is for the thermostat to run the heat pump in bursts short enough to keep the back up heat from running.

Anyone familiar with this? Consumer Reports doesn't mention this in a quick look at a few thermostats. The do list "Early recovery" which turns on the heat/cooling ahead of the set time so the home is at the right temperature when you arrive (rather pointless in my opinion since I can just set the time early if that is what I wanted.)

They are starting to address the ToU billing issue in EV charging. Any sign of this in home heating/cooling?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

Honeywell VisionPro Series has adaptive recovery. You set the time and
temp for what you want it to actually be and for recovery after setback
it then figures out what time to fire it up to get it there. And it learns.

That is exactly wrong for my situation. I mentioned that in my first post. Another company calls it "Early recovery".


It works excellent with the gas furnace here and it supports heat pumps,
so I would expect it will work the same with those. IDK what algorithm
they use, but obviously it's based on how big the delta is that it has
to close and how fast the thermostat knows it takes to raise the temp one
degree. Besides that, I would think it may factor in how fast the temp
has dropped while in setback, to get some gauge as to how cold it is
outside, to further refine the calculation. It always makes it to the
desired temp by the desired time.

Yeah, that sounds like it works well, but it's a great solution to the wrong problem.

OK, you're right. But it's a similar problem, a very common problem
and I would think you would have that too.
How much does the temp drop during these high energy cost periods when
you have the system off? The temp also drops if you set it back at
night to save energy or maybe you just don't. But if you set it back,
when it has to resume at 6AM, the same thing happens. If the temp
delta is big enough, then it kicks on aux heat.

The VisionPros do have a programmable aux heat lockout
which you can set for between 40 to 60F outside temp. It obviously then
requires an outside temp sensor. If the outside temp is above the setting,
then it locks out the electric aux heat. So you could have it locked out
for above 40F. Do you need aux heat at all? If not, just disable it.

They should have more options, like an intelligent mode where
it only kicks in aux heat if it's going to take longer than X mins to
reach the new setting. That's the kind of setting it would have to
have or a more primitive one based on just the temp delta. AFAIK
the VisioPros just use the latter method and IDK if it can be programmed.

 

[Rick C]

On Saturday, January 11, 2020 at 2:22:08 PM UTC-5, Whoey Louie wrote:

On Saturday, January 11, 2020 at 12:07:33 PM UTC-5, Rick C wrote:
On Saturday, January 11, 2020 at 11:12:33 AM UTC-5, Whoey Louie wrote:
On Friday, January 10, 2020 at 10:54:48 PM UTC-5, Rick C wrote:
I am using a programmable thermostat to turn off the heat and/or air conditioning during the peak usage times as set by the ToU billing with my utility. The problem I have is the heat pump not ramping up the temperature fast enough when it comes back on and the backup straight electric heat coming on. This uses maybe three times the amount of electricity during the time it takes to get up to temperature.

I don't know if this is caused by the thermostat or the heat pump itself. I'm wondering if anyone makes a programmable thermostat that deals with this issue. If the problem is caused by the thermostat not letting the heat pump run long enough that is easy to fix. If the problem is caused by the heat pump itself, then the way to deal with it is for the thermostat to run the heat pump in bursts short enough to keep the back up heat from running.

Anyone familiar with this? Consumer Reports doesn't mention this in a quick look at a few thermostats. The do list "Early recovery" which turns on the heat/cooling ahead of the set time so the home is at the right temperature when you arrive (rather pointless in my opinion since I can just set the time early if that is what I wanted.)

They are starting to address the ToU billing issue in EV charging. Any sign of this in home heating/cooling?

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

Honeywell VisionPro Series has adaptive recovery. You set the time and
temp for what you want it to actually be and for recovery after setback
it then figures out what time to fire it up to get it there. And it learns.

That is exactly wrong for my situation. I mentioned that in my first post. Another company calls it "Early recovery".


It works excellent with the gas furnace here and it supports heat pumps,
so I would expect it will work the same with those. IDK what algorithm
they use, but obviously it's based on how big the delta is that it has
to close and how fast the thermostat knows it takes to raise the temp one
degree. Besides that, I would think it may factor in how fast the temp
has dropped while in setback, to get some gauge as to how cold it is
outside, to further refine the calculation. It always makes it to the
desired temp by the desired time.

Yeah, that sounds like it works well, but it's a great solution to the wrong problem.


OK, you're right. But it's a similar problem, a very common problem
and I would think you would have that too.

Not trying to be rude, but if you think I have both problems, then you don't understand the problem I am having.

I want the heat to be OFF during the peak times of my ToU rates. Not reduced, not cut back, OFF.

I can do that by programming the thermostat low enough that the heat never comes on. But when the peak time is over, the temperature setting is restored to the intended setting and the heat comes on. After some time the back up heat comes on and the electric meter spins like a top.

If the house temperature were ramped up one degree at a time over an hour say, it might not kick in the back up heat and not waste the money I'm trying to save.

How much does the temp drop during these high energy cost periods when
you have the system off?

Sometimes three or four degrees.

The temp also drops if you set it back at
night to save energy or maybe you just don't.

I don't have enough settings to do that. Peak time is 6 to 9 in the morning and 5 to 8 in the evening. That's four sets per day, my max.

Not so worried about the night setting. It's already rather low. The room I spend my time in has more than an even amount of heat flowing to it and its comfy with the rest of the house some 4 degrees lower. The normal thermostat setting is 62 degrees.

But if you set it back,
when it has to resume at 6AM, the same thing happens. If the temp
delta is big enough, then it kicks on aux heat.

Exactly, but that's the time I turn the heat off, so I don't want it starting at a low temperature.

The VisionPros do have a programmable aux heat lockout
which you can set for between 40 to 60F outside temp. It obviously then
requires an outside temp sensor. If the outside temp is above the setting,
then it locks out the electric aux heat. So you could have it locked out
for above 40F. Do you need aux heat at all? If not, just disable it.

That won't work. When the outside temps are in the teens (unusual, but not unheard of) the backup heat is required absolutely. In fact, I think the crossover point for my system is 26 degrees. I don't know if that is set by the furnace or the thermostat. I suspect it is the furnace since I don't think the thermostat knows the outside temperature, but not sure.

They should have more options, like an intelligent mode where
it only kicks in aux heat if it's going to take longer than X mins to
reach the new setting. That's the kind of setting it would have to
have or a more primitive one based on just the temp delta. AFAIK
the VisioPros just use the latter method and IDK if it can be programmed.

One of the heat pumps I bought the manufacturer would not allow access to these settings. You had to contact the installer. I forget the brand, but that system would be running the backup heat in the middle of the afternoon when it was 50°F outside. No one could ever explain why. They would just run down the list of reasons to run the backup heat as if it would be one of those.

I don't care how long it takes to reach the new setting. It takes how ever long it takes. I just don't want it running backup heat unless it is actually needed to keep the house warm.

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Winfield Hill]

Rick C wrote...

On Saturday, January 11, 2020, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

I suspect if you check with someone who knows, your backup
heat will also run under two other conditions. One is the
system detects ice on the outside coils. With a 40 degree
cut off, your system might not worry with deicing.

Good point, maybe. The instructions don't say anything
about limitations or features if I lower the threshold.
It may not have an ice-detection feature.

The other condition is when the system runs long enough that
it decides the heat pump is not doing the job and switches
to backup heat. Oops, another condition is if the inside
temperature drops too far bellow the set temperature.

It's possible I don't have the first mode. It will add
the aux heat, if inside temp drops below 45F. It does
run the system differently with the heatpump (which draws
5kW when running), than with the furnace. In the former
case it runs the forced-air blower much slower, and it
appears to start the morning temp rampup much earlier.

I haven't been able to observe the heatpump unable to
get the house up to temp on its own. Our heating/HVAC
system started as an oil furnace and air-conditioner,
but they upgraded the compressor to heat pump (modest
low cost). But the hybrid thermostat labels the heat
pump as primary, and the oil furnace as auxiliary.

The heat-pump compressor's 24-page manual mentions an
optional Secondary Outdoor Thermostat, which can turn
on a 3rd-stage of supplemental electric heaters, to
avoid ice buildup, I suppose. I doubt we have that.
So far I'm happy with the default 40-degree setting.
But, if our aux heat was electric baseboard, etc.,
of course that'd be another matter entirely.

If we ever decide to forgo using oil, as some suggest,
we'll upgrade to a proper geothermal heat pump system.
But that might trigger a complete HVAC makeover, and
could involve adding more roof solar panels as well.
Our installer, next town over, in Melrose, MA, has
such a system, and is a big fan of that approach.


--
Thanks,
- Win

 

[Winfield Hill]

Rick C wrote...

They should have more options ...

You know, it's time to fire up your Arduino
coding brain, and take back full control.


--
Thanks,
- Win

 

[Rick C]

On Saturday, January 11, 2020 at 2:46:13 PM UTC-5, Winfield Hill wrote:

Rick C wrote...

On Saturday, January 11, 2020, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

I suspect if you check with someone who knows, your backup
heat will also run under two other conditions. One is the
system detects ice on the outside coils. With a 40 degree
cut off, your system might not worry with deicing.

Good point, maybe. The instructions don't say anything
about limitations or features if I lower the threshold.
It may not have an ice-detection feature.

The other condition is when the system runs long enough that
it decides the heat pump is not doing the job and switches
to backup heat. Oops, another condition is if the inside
temperature drops too far bellow the set temperature.

It's possible I don't have the first mode. It will add
the aux heat, if inside temp drops below 45F. It does
run the system differently with the heatpump (which draws
5kW when running), than with the furnace. In the former
case it runs the forced-air blower much slower, and it
appears to start the morning temp rampup much earlier.

Mine runs the blower fast with both types of heat, but runs it slower after the compressor has shut off to capture the last residual heat without lowering the temperature of the air from the vents.

I haven't been able to observe the heatpump unable to
get the house up to temp on its own. Our heating/HVAC
system started as an oil furnace and air-conditioner,
but they upgraded the compressor to heat pump (modest
low cost). But the hybrid thermostat labels the heat
pump as primary, and the oil furnace as auxiliary.

Of course. Better to run the more economical heat source when you can.

The heat-pump compressor's 24-page manual mentions an
optional Secondary Outdoor Thermostat, which can turn
on a 3rd-stage of supplemental electric heaters, to
avoid ice buildup, I suppose. I doubt we have that.
So far I'm happy with the default 40-degree setting.
But, if our aux heat was electric baseboard, etc.,
of course that'd be another matter entirely.

If/when oil goes back up to $4 a gal you may rethink that.

If we ever decide to forgo using oil, as some suggest,
we'll upgrade to a proper geothermal heat pump system.
But that might trigger a complete HVAC makeover, and
could involve adding more roof solar panels as well.
Our installer, next town over, in Melrose, MA, has
such a system, and is a big fan of that approach.

Not sure why it might need more solar panels. If anything it would be less.. I suppose since it will run all the time including really cold nights, it will need to move more heat than your current heat pump, but with the constant temperature of the ground it would have a much easier time of it. The whole point of the geothermal is to *reduce* your heating bill. If you need more solar panels you are doing something wrong.

Consider the actual work required. Lifting 2 tons of goods by 15 feet or lifting 2 tons of good 5 feet. Which is more work?

The more I think about it the less I like the idea of the 40°F cutoff on the heat pump. It's barely doing anything for you. It's just doing the light duty work and less of it.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Rick C]

On Saturday, January 11, 2020 at 2:50:54 PM UTC-5, Winfield Hill wrote:

Rick C wrote...

They should have more options ...

You know, it's time to fire up your Arduino
coding brain, and take back full control.

I would if I had a full spec on the heat pump. I still don't know where the various decisions are made, thermostat vs. heat pump.

As I think I've mentioned, I've tried to get more info on another system before and the manufacturer won't talk to me as a customer. In fact, they would not even talk to me unless I gave them a serial number that I could only access by taking the thermostat partially apart. lol

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[whit3rd]

On Saturday, January 11, 2020 at 11:42:49 AM UTC-8, Rick C wrote:

On Saturday, January 11, 2020 at 2:22:08 PM UTC-5, Whoey Louie wrote:

... you don't understand the problem I am having.

I want the heat to be OFF during the peak times of my ToU rates. Not reduced, not cut back, OFF.

The issue here, is that no man can serve two masters, and no thermostat can be said
to be doing the 'keep temperature constant' task when it is imperative that the
heat be OFF.

You can always put a relay cutoff in series with the heat-element, timed for the
service rates. Or, maybe install an electric subpanel on a timed contactor. I've seen
dual-meter setups that did something comparable.

But informing the logic of a thermostat requires a level of control that can only be called
intelligence. It won't be a thermostat any more.

 

whit3rd <whit3rd@gmail.com> wrote in
news:9277545f-c197-4cec-a7f1-0fe0f56ffbcc@googlegroups.com:

On Saturday, January 11, 2020 at 11:42:49 AM UTC-8, Rick C wrote:
On Saturday, January 11, 2020 at 2:22:08 PM UTC-5, Whoey Louie
wrote:

... you don't understand the problem I am having.

I want the heat to be OFF during the peak times of my ToU rates.
Not reduced, not cut back, OFF.

The issue here, is that no man can serve two masters, and no
thermostat can be said to be doing the 'keep temperature constant'
task when it is imperative that the heat be OFF.

You can always put a relay cutoff in series with the heat-element,
timed for the service rates. Or, maybe install an electric
subpanel on a timed contactor. I've seen dual-meter setups that
did something comparable.

But informing the logic of a thermostat requires a level of
control that can only be called intelligence. It won't be a
thermostat any more.

I'll would be willing to bet that there is an iPad for your wall,
and an app for that. Should be able to be far more intelligant than
the normal fare.

 

[Rick C]

On Saturday, January 11, 2020 at 3:31:47 PM UTC-5, whit3rd wrote:

On Saturday, January 11, 2020 at 11:42:49 AM UTC-8, Rick C wrote:
On Saturday, January 11, 2020 at 2:22:08 PM UTC-5, Whoey Louie wrote:

... you don't understand the problem I am having.

I want the heat to be OFF during the peak times of my ToU rates. Not reduced, not cut back, OFF.

The issue here, is that no man can serve two masters, and no thermostat can be said
to be doing the 'keep temperature constant' task when it is imperative that the
heat be OFF.

So??? There are different demands at different times. That's not exactly unique in the world of machines. Your car isn't taking you anywhere when it is OFF. Your TV isn't showing you anything when it is OFF. Many objects are turned on and off automatically by timers, like dishwashers that come on late at night.

You can always put a relay cutoff in series with the heat-element, timed for the
service rates. Or, maybe install an electric subpanel on a timed contactor. I've seen
dual-meter setups that did something comparable.

But informing the logic of a thermostat requires a level of control that can only be called
intelligence. It won't be a thermostat any more.

Lol. Ok, call it intelligence. That doesn't change the task.

I'm not sure what you read. If you read my description of what I am asking for you might understand my present thermostat already turns the heat on and off as required. I'm looking for a way to do that so the backup heat doesn't turn on when ramping the temperature back up. A relay would very likely still kick in the backup heat.

--

Rick C.

--- Get 1,000 miles of free Supercharging
--- Tesla referral code - https://ts.la/richard11209

 

[Winfield Hill]

Rick C wrote...

... A relay would very likely still kick in the backup heat.

How about adding a high-current contactor, with timer,
to disable the backup heat when you want to do so.


--
Thanks,
- Win

 

[Rick C]

On Saturday, January 11, 2020 at 3:44:58 PM UTC-5, Winfield Hill wrote:

Rick C wrote...

... A relay would very likely still kick in the backup heat.

How about adding a high-current contactor, with timer,
to disable the backup heat when you want to do so.

I was thinking of something less intrusive, like a properly programmable thermostat.

I just thought someone here might have seen this before. I did a search of thermostats, but all the hype and BS gets in the way of seeing what many of them actually do. Even Consumer Reports doesn't seem to have considered this issue and they seem to reflect what the thermostat makers provide, so maybe it's not out there and I need to roll my own.

There is a fairly cost effective FPGA board with a large LCD display. That might be a good choice, but I'm not ready to start designing just yet.

--

Rick C.

--+ Get 1,000 miles of free Supercharging
--+ Tesla referral code - https://ts.la/richard11209

 

[John S]

On 1/11/2020 2:14 PM, Rick C wrote:

On Saturday, January 11, 2020 at 2:46:13 PM UTC-5, Winfield Hill wrote:
Rick C wrote...

On Saturday, January 11, 2020, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

I suspect if you check with someone who knows, your backup
heat will also run under two other conditions. One is the
system detects ice on the outside coils. With a 40 degree
cut off, your system might not worry with deicing.

Good point, maybe. The instructions don't say anything
about limitations or features if I lower the threshold.
It may not have an ice-detection feature.

The other condition is when the system runs long enough that
it decides the heat pump is not doing the job and switches
to backup heat. Oops, another condition is if the inside
temperature drops too far bellow the set temperature.

It's possible I don't have the first mode. It will add
the aux heat, if inside temp drops below 45F. It does
run the system differently with the heatpump (which draws
5kW when running), than with the furnace. In the former
case it runs the forced-air blower much slower, and it
appears to start the morning temp rampup much earlier.

Mine runs the blower fast with both types of heat, but runs it slower after the compressor has shut off to capture the last residual heat without lowering the temperature of the air from the vents.


I haven't been able to observe the heatpump unable to
get the house up to temp on its own. Our heating/HVAC
system started as an oil furnace and air-conditioner,
but they upgraded the compressor to heat pump (modest
low cost). But the hybrid thermostat labels the heat
pump as primary, and the oil furnace as auxiliary.

Of course. Better to run the more economical heat source when you can.


The heat-pump compressor's 24-page manual mentions an
optional Secondary Outdoor Thermostat, which can turn
on a 3rd-stage of supplemental electric heaters, to
avoid ice buildup, I suppose. I doubt we have that.
So far I'm happy with the default 40-degree setting.
But, if our aux heat was electric baseboard, etc.,
of course that'd be another matter entirely.

If/when oil goes back up to $4 a gal you may rethink that.


If we ever decide to forgo using oil, as some suggest,
we'll upgrade to a proper geothermal heat pump system.
But that might trigger a complete HVAC makeover, and
could involve adding more roof solar panels as well.
Our installer, next town over, in Melrose, MA, has
such a system, and is a big fan of that approach.


Not sure why it might need more solar panels. If anything it would be less. I suppose since it will run all the time including really cold nights, it will need to move more heat than your current heat pump, but with the constant temperature of the ground it would have a much easier time of it. The whole point of the geothermal is to *reduce* your heating bill. If you need more solar panels you are doing something wrong.

Consider the actual work required. Lifting 2 tons of goods by 15 feet or lifting 2 tons of good 5 feet. Which is more work?

The more I think about it the less I like the idea of the 40°F cutoff on the heat pump. It's barely doing anything for you. It's just doing the light duty work and less of it.

What is your quest? You need to save money, or what?

 

[Rick C]

On Saturday, January 11, 2020 at 4:38:06 PM UTC-5, John S wrote:

On 1/11/2020 2:14 PM, Rick C wrote:
On Saturday, January 11, 2020 at 2:46:13 PM UTC-5, Winfield Hill wrote:
Rick C wrote...

On Saturday, January 11, 2020, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

I suspect if you check with someone who knows, your backup
heat will also run under two other conditions. One is the
system detects ice on the outside coils. With a 40 degree
cut off, your system might not worry with deicing.

Good point, maybe. The instructions don't say anything
about limitations or features if I lower the threshold.
It may not have an ice-detection feature.

The other condition is when the system runs long enough that
it decides the heat pump is not doing the job and switches
to backup heat. Oops, another condition is if the inside
temperature drops too far bellow the set temperature.

It's possible I don't have the first mode. It will add
the aux heat, if inside temp drops below 45F. It does
run the system differently with the heatpump (which draws
5kW when running), than with the furnace. In the former
case it runs the forced-air blower much slower, and it
appears to start the morning temp rampup much earlier.

Mine runs the blower fast with both types of heat, but runs it slower after the compressor has shut off to capture the last residual heat without lowering the temperature of the air from the vents.


I haven't been able to observe the heatpump unable to
get the house up to temp on its own. Our heating/HVAC
system started as an oil furnace and air-conditioner,
but they upgraded the compressor to heat pump (modest
low cost). But the hybrid thermostat labels the heat
pump as primary, and the oil furnace as auxiliary.

Of course. Better to run the more economical heat source when you can.


The heat-pump compressor's 24-page manual mentions an
optional Secondary Outdoor Thermostat, which can turn
on a 3rd-stage of supplemental electric heaters, to
avoid ice buildup, I suppose. I doubt we have that.
So far I'm happy with the default 40-degree setting.
But, if our aux heat was electric baseboard, etc.,
of course that'd be another matter entirely.

If/when oil goes back up to $4 a gal you may rethink that.


If we ever decide to forgo using oil, as some suggest,
we'll upgrade to a proper geothermal heat pump system.
But that might trigger a complete HVAC makeover, and
could involve adding more roof solar panels as well.
Our installer, next town over, in Melrose, MA, has
such a system, and is a big fan of that approach.


Not sure why it might need more solar panels. If anything it would be less. I suppose since it will run all the time including really cold nights, it will need to move more heat than your current heat pump, but with the constant temperature of the ground it would have a much easier time of it. The whole point of the geothermal is to *reduce* your heating bill. If you need more solar panels you are doing something wrong.

Consider the actual work required. Lifting 2 tons of goods by 15 feet or lifting 2 tons of good 5 feet. Which is more work?

The more I think about it the less I like the idea of the 40°F cutoff on the heat pump. It's barely doing anything for you. It's just doing the light duty work and less of it.


What is your quest? You need to save money, or what?

Why does that matter? Are you going to analyze my justification for wanting this?

--

Rick C.

-+- Get 1,000 miles of free Supercharging
-+- Tesla referral code - https://ts.la/richard11209

 

[Whoey Louie]

On Saturday, January 11, 2020 at 3:17:14 PM UTC-5, Rick C wrote:

On Saturday, January 11, 2020 at 2:50:54 PM UTC-5, Winfield Hill wrote:
Rick C wrote...

They should have more options ...

You know, it's time to fire up your Arduino
coding brain, and take back full control.

I would if I had a full spec on the heat pump. I still don't know where the various decisions are made, thermostat vs. heat pump.

Not hard to figure out. RTFM. The thermostat almost certainly has a
wire that calls for heat and a wire that calls for aux heat. If it's
two stage, then it has two heat call wires.

As I think I've mentioned, I've tried to get more info on another system before and the manufacturer won't talk to me as a customer. In fact, they would not even talk to me unless I gave them a serial number that I could only access by taking the thermostat partially apart. lol

Well, I suppose if you buy a thermostat that made by the heat pump
manufacturer, that's locked to their equipment, etc, then you're at
their mercy. It's Trane and similar that want you to think they are
superior that generally do that and they soak you too. That's why
I have a Rheem.

If you really want to get creative, I suppose you could get a wifi thermostat
and then write a program that talks to it and raises the set temp one
or two deg at a time when you want it to recover, so that aux heat is not
triggered. It's funny, today we even have wifi thermostats, but apparently
most of them can't handle the obvious things, like giving you flexibility
and control over how aux heat is called for. Time to download the manuals
for the smart thermostats and see if they do. That is assuming you can
replace your thermostat, that it's not tied to the eqpt by the manufacturer..

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209

 

[John S]

On 1/11/2020 3:47 PM, Rick C wrote:

On Saturday, January 11, 2020 at 4:38:06 PM UTC-5, John S wrote:
On 1/11/2020 2:14 PM, Rick C wrote:
On Saturday, January 11, 2020 at 2:46:13 PM UTC-5, Winfield Hill wrote:
Rick C wrote...

On Saturday, January 11, 2020, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

I suspect if you check with someone who knows, your backup
heat will also run under two other conditions. One is the
system detects ice on the outside coils. With a 40 degree
cut off, your system might not worry with deicing.

Good point, maybe. The instructions don't say anything
about limitations or features if I lower the threshold.
It may not have an ice-detection feature.

The other condition is when the system runs long enough that
it decides the heat pump is not doing the job and switches
to backup heat. Oops, another condition is if the inside
temperature drops too far bellow the set temperature.

It's possible I don't have the first mode. It will add
the aux heat, if inside temp drops below 45F. It does
run the system differently with the heatpump (which draws
5kW when running), than with the furnace. In the former
case it runs the forced-air blower much slower, and it
appears to start the morning temp rampup much earlier.

Mine runs the blower fast with both types of heat, but runs it slower after the compressor has shut off to capture the last residual heat without lowering the temperature of the air from the vents.


I haven't been able to observe the heatpump unable to
get the house up to temp on its own. Our heating/HVAC
system started as an oil furnace and air-conditioner,
but they upgraded the compressor to heat pump (modest
low cost). But the hybrid thermostat labels the heat
pump as primary, and the oil furnace as auxiliary.

Of course. Better to run the more economical heat source when you can.


The heat-pump compressor's 24-page manual mentions an
optional Secondary Outdoor Thermostat, which can turn
on a 3rd-stage of supplemental electric heaters, to
avoid ice buildup, I suppose. I doubt we have that.
So far I'm happy with the default 40-degree setting.
But, if our aux heat was electric baseboard, etc.,
of course that'd be another matter entirely.

If/when oil goes back up to $4 a gal you may rethink that.


If we ever decide to forgo using oil, as some suggest,
we'll upgrade to a proper geothermal heat pump system.
But that might trigger a complete HVAC makeover, and
could involve adding more roof solar panels as well.
Our installer, next town over, in Melrose, MA, has
such a system, and is a big fan of that approach.


Not sure why it might need more solar panels. If anything it would be less. I suppose since it will run all the time including really cold nights, it will need to move more heat than your current heat pump, but with the constant temperature of the ground it would have a much easier time of it. The whole point of the geothermal is to *reduce* your heating bill. If you need more solar panels you are doing something wrong.

Consider the actual work required. Lifting 2 tons of goods by 15 feet or lifting 2 tons of good 5 feet. Which is more work?

The more I think about it the less I like the idea of the 40°F cutoff on the heat pump. It's barely doing anything for you. It's just doing the light duty work and less of it.


What is your quest? You need to save money, or what?

Why does that matter? Are you going to analyze my justification for wanting this?

Yes. Why else would I ask? Can you answer civilly? Or are you just being
a troll?