[kwlug-disc] (Off Topic) Furnaces and Heat Pumps

[Anton Avramov]

Hi, 

We went through this some time back when I felt the old furnace is end
of life and we also wanted to take advantage of the rebates. 

We eventually settled on Daikin Heat Pump from Able Air and it was sold
to us by the Rep by: 
- The only furnace that is actually made for cold climate where as
others are just a combination the heat pump outside, a furnace and
control boards sometimes from different brands and only with 2-3 modes
of operation. 
- The variable motor designed for continuous operation with a Daikin
controller that actually utilize the full 32 speeds of the motor (I
think it was 32 speeds). 

I've never actually verified those, but the Rep sounded convincing so
take those with a grain of salt. 

Yes, there is no direct API to the Thermostat but the cloud integration
for Home Assistant works and I had no problems with it. 

Now my specific unit did had some problems and they had to replace the
control boards of the Heat Pump outside a couple of times and even had
a representative of Daikin come and investigate what was the problem,
but eventually they figure it out. The support was good. 
The good thing was that when it detected it has a problem with the Heat
pump it just switched to gas and we are never left in the cold.

Now once or twice a year the thermostat detects there may be a problem
with the heat pump and I should contact support, but the last time just
restarting the units clear the error. 
They suggested it might be some surges on the power grid and I should
get a Surge Protection. Conveniently Able Air owner's brother had an
electrical service and they did send me a quote for that, but I ended
up using my own electrician and added a surge protection for the hole
house. 

He had also installed Heat Pump recently and said the installer
provided the purge protection as part of the installation, so you might
check with your installer about that in advance. They might throw it
for free. 

I'm not sure what more can I say. 
I don't actually control the heat pump with home assistant because I
use it's build in schedule. In my Daikin thermostat you can have 4
diffident schedules for each day of the week.
Since we believe it's better to sleep in a little lower temperature I
set the temp to 19C in 23h and then gradually increase it to 20.5 in 4h
21.5 in 5 and 22 in 6h. 
I do this because the heat pump works much slower that the furnace and
it takes time to build the temperature back up. If the temp diff is too
big and the thermostat detects it can bring the temperature back up
quick enough it would automatically use the gas furnace as needed. 

If you have any questions I'll be happy to answer them if I can. 
Here is a snapshot of the sensors in home assistant: 


Main Room
-3 °C
-3 °C / -3 °C
Main Room Air Handler Critical Fault Code
Unknown
Main Room Air Handler Minor Fault Code
Unknown
Main Room EEV Coil Critical Fault Code
0
Main Room EEV Coil Minor Fault Code
0
Main Room Indoor cooling actual
0.0%
Main Room Indoor cooling demand
0.0%
Main Room Indoor dehumidifier demand
0.0%
Main Room Indoor fan actual
56.5%
Main Room Indoor fan demand
56.5%
Main Room Indoor furnace actual
0.0%
Main Room Indoor furnace blower airflow
791 ft³/min
Main Room Indoor Furnace Critical Fault Code
0
Main Room Indoor furnace demand
0.0%
Main Room Indoor Furnace Minor Fault Code
0
Main Room Indoor humidifier demand
0.0%
Main Room Indoor humidity
41%
Main Room Indoor power
1,723 W
Main Room Indoor temperature
21.9 °C
Main Room Outdoor air temperature
-4.5 °C
Main Room Outdoor aqi
28
Main Room Outdoor cooling demand
0.0%
Main Room Outdoor Critical Fault Code
0
Main Room Outdoor fan demand
56.0%
Main Room Outdoor frequency in percent
43.0%
Main Room Outdoor heat pump demand
43.0%
Main Room Outdoor humidity
41%
Main Room Outdoor Minor Fault Code
0
Main Room Outdoor ozone
163 μg/m³
Main Room Outdoor pm1
5 μg/m³
Main Room Outdoor power
1,360 W
Main Room Outdoor temperature
-3.0 °C
Main Room Thermostat Critical Fault Code
0
Main Room Thermostat Minor Fault Code
0

Best Regards

On Mon, 2026-03-02 at 12:32 -0500, Chris Irwin via kwlug-disc wrote:
> After the OT discussion on Water Heaters, I realized the Smart Home 
> people in this group might know more about furnaces and heat pumps
> than 
> me.
> 
> My furnace died. I've been working on getting it replaced, but it's
> more 
> work than you'd expect if you have any questions during the process.
> I 
> could sign the paperwork for a basic furnace and a/c and have it 
> installed next day. But I was curious about heat pumps, and these 
> questions typically take a day to answer, and then trigger more 
> questions. It's been *a week* of back and forth with two different 
> companies about this.
> 
> I was originally quoted for a "Rheem" heat pump + furnace that was 
> comparable in cost to a regular A/C + furnace. Seemed like a simple 
> decision. However, after doing my own research, I realized it wasn't
> a 
> "cold-climate" heat pump, and it's effective heat output at cold 
> temperatures is significantly diminished (even if the efficency of
> said 
> heat is good, there just isn't very much heat). It would probably
> help 
> in spring/fall, but not for most of the winter.
> 
> Upon asking about this, they helpfully confirmed the above, and gave
> a 
> quote on "Gree" cold-climate rated heat pump, which is (as expected)
> a 
> bit more money, but initially appears significantly better in the
> cold 
> (I haven't done my full research on it yet, I just got this quote
> this 
> morning). Gree appears to be a made in China affair.
> 
> One thing that I like is that this solution uses a normal Ecobee,
> which 
> I'm already familiar with, and I know it integrates nicely with Home 
> Assistant using a *local* api (apple homekit -- no apple devices 
> required)
> 
> I've been quoted by a second company for a "Daikin" solution, which
> is 
> (despite the Japanese branding) apparently made in USA (which isn't a
> selling feature ATM, other than to say parts are likely easier to
> get). 
> This appears to actually be a pretty good unit efficiency-wise,
> however 
> they require use of their own proprietary themostat. Apparently it
> does 
> a data connection to the furnace, rather than the traditional wires a
> "normal" thermostat would use. Apparently that method is more
> efficient 
> (instead of 2/3 stages, it's fully variable speed, etc.). 
> 
> But there's no local API for the Daikin. There is a Cloud API, but
> I'm 
> not sure about it's capabilities, or logevity, though it does appear
> to 
> be available in Home Assistant.
> 
> (There's also a Daikin thermostat compatability board that costs
> extra, 
> would need to be installed in the furnace, and would probably
> invaidate 
> some of my support -- and possibly limit some of the efficiency
> gains. 
> It also appears to be a source of frustration online)
> 
> The home assistant integration is somewhat important to me, partly
> from 
> a data-logging POV, but also as none of these solutions implement 
> TOU-rate awareness on their own.
> 
> So my questions:
> 
> 1. Anybody heard of "Gree" or "Daikin"?
> 
> 2. Anybody used Daikin's thermostat? Or their Home Assistant 
> integration?
> 
> 3. Anybody know anything special I should know? The problem is I
> didn't 
> do any research in advance of my furnace kicking the bucket, and I
> can't 
> help but feel like I'm being rushed into a purchase. Which I am, but
> I'd 
> like to make a decently educated purchase decision.
> 
> And to be clear, I'm not sure I'll ever actually recoup any
> signficant 
> savings from the heat pump. I've done a fair amount of calulation on
> a 
> spreadsheet to project costs (which I'll share when I'm happy with
> it), 
> but it's not directly applicable to the real world (unless we can
> assume 
> a static temperature for a whole month). My main goal is to reduce
> gas 
> usage where possible, but without going broke to do that.
> 
>