RV10flyer
Solar Wizard
- Joined
- Mar 8, 2021
- Messages
- 1,198
At what outdoor temperature and indoor setpoint. 2 hrs between cycles?
Heatpump water heater etc....
- Thread starter Ai4px
- Start date
What's handy about our system is that the ductwork is in my conditioned basement. If I have duct leaks, it's a good thing! I've got 2400 ft^2 up and 2400 down that is heated and cooled. 480m^2 total. Also the basement is surrounded by a 8' 2.5m wide hallway the entire way around that further insulates the house. The house has an 8' wide southern porch the entire way around and that hall way in basement is under the porch.Not OP but I dug out some info on ducted mini split project for some DMs
For a project last year, I was interested in the Fujitsu medium-static models. This is designed for concealed duct, I think custom designed for mini-split. Medium static means it can handle more ductwork than a low static model (albeit at a potential efficiency deficit, though efficiency needs to be considered holistically vs how much insulation is surrounding the ducts, sometimes you want high static to push it faster)
ARU12RGLX = 3100 - 19400 (BTU range heating)
Oops, this one is retired. Here is the product line.
Medium Static Pressure Duct - AIRSTAGE SINGLE-ROOM MINI-SPLIT SYSTEMS - Residential - FUJITSU GENERAL United States & Canada
Medium Static Pressure Duct - AIRSTAGE SINGLE-ROOM MINI-SPLIT SYSTEMS - Residential - FUJITSU GENERAL United States & Canadawww.fujitsu-general.com
Next week I'm getting a Mitsubishi multi-position air handler installed
SVZ-KP36NA_SUZ-KA36NA2
IIRC this is a mid and high static unit. It is designed to drop into air handler or furnace for a whole house.
We keep the indoor at 72F (21C).... outside temp was 14F -10C ... the coldest it's even been here.
zanydroid
Solar Wizard
Hmm, OK, since I haven't gotten a HPWH yet I don't have details on this either, except on the broad strokes of how I would approach it.
Apart from CTA-2045 I also considered digging into the WiFi protocol as an alternative. I believe all of the HPWH on the market have a smart controller on it.
And the workflows to investigate were to get gentle demand response / energy management. I don't want to slam the compressor shut by cutting power to the HPWH using a relay, I'd rather just tell it to turn off resistive heat. This kind of control is *supposed* to be what that smart app is for.
What I'm not sure of is can you get to all the woolybooger details via the demand control device? I think not.... but a ESP32 querying modbus and relaying to MQTT would be interesting.
Wow, amazing. I may have to get a mini-split for next winter.
zanydroid
Solar Wizard
.
I know... don't really care. But I have edited it now.
zanydroid
Solar Wizard
It's probably been done, let me google for CTA-2045 and Home Assistant.
In general if the serial bus is this easy to decode, it's probably been done.
In case you were unaware, the serial control bus on Mitsubishi has been decoded a while back (it's just a basic TX/RX pair) and there is ESP software and an easy-ish to buy dongle that you can get. The register set (read/write) is pretty good.
zanydroid
Solar Wizard
Any solution for CTA 2045 and MQTT - HomeSeer Message Board
I will be getting a new builder supplied Hot water heater (no I don't get a choice here) that has a CT2045 port. These were designed for allowing the Utility Energy supplier to control energy use at the device. I have been looking for a method that would allow for control on HomeSeer without...
webcache.googleusercontent.com
It's a little more primitive and less popular than I expected (IE, there were some posts on reddit from 2021 where people asked about it but kind of threw in the towel) but this thread seems promising.
Quattrohead
Solar Wizard
I know these get grumpy if they think an element is open circuit, but I wonder if you can rewire them into series to get 1125w of warming.
MODBUS is easy... talk to it over a serial link..... whats more challenging is knowing which register does what and how they are scaled.
svetz
Works in theory! Practice? That's something else
Thanks for sharing your data, I'm bookmarking this thread as the next time the water heater here dies I plan on switching to one. Hopefully, it'll reduce the load on the garage dehumidifier.
They look very expensive, but I've seen external DIY units you can hook to an electric water heater (the idea being the heat exchange lasts longer than the tank). If your tank goes, can you swap the heat exchanger rather than replace the whole thing?
Were there any local energy credits, or just the federal?
They look very expensive, but I've seen external DIY units you can hook to an electric water heater (the idea being the heat exchange lasts longer than the tank). If your tank goes, can you swap the heat exchanger rather than replace the whole thing?
Were there any local energy credits, or just the federal?
Last edited:
zanydroid
Solar Wizard
I meant swap both elements to smaller size
Series wiring on 120v would be harder than usually because there is a 240v compressor so you would need a schematic. There is also a 240v to DC power supply in there for the smart circuitry but it will probably be fine.
OffGridInTheCity
Solar Wizard
I've been running a 50gal Rheems hybrid (heat-pump) for a few years now. In heat-pump only mode it maxes out at 400w. Mine is under the house with 50F winter and 80F summer ambient + has ~200ft of water circulation for instant hot water at the taps = 10%? extra power.
Here's the power consumption over a couple of years in kwhs / month in heat-pump only mode...
It's been flawless in operation except... when it was turned on for the very 1st time, it insisted in activating the 4,500w heating element(s) before letting me put it in heat-pump only mode - which would have blown a 500w inverter. Fortunately my inverter is 12,000w so it was OK.
Here's the power consumption over a couple of years in kwhs / month in heat-pump only mode...
It's been flawless in operation except... when it was turned on for the very 1st time, it insisted in activating the 4,500w heating element(s) before letting me put it in heat-pump only mode - which would have blown a 500w inverter. Fortunately my inverter is 12,000w so it was OK.
400bird
Solar Wizard
Yeah, following this thread.
I'd love to see modbus, mqtt, or any communication published on a HPWH. That would allow me to run it up to a higher temp as a small dump load and maintain a normal temp if someone takes a 8pm shower or I run the dishwasher at night.
I've been eyeing the 80 gallon Stiebel Eltron from AltE, it has an input that allows a second, higher water temp set point on command all I would need is a relay/dry contact. But, it doesn't support any data out. So, I could allow the higher temp, but I couldn't see what was happening with the water temp. In reality, that's not important, but I like data.
I'd love to see modbus, mqtt, or any communication published on a HPWH. That would allow me to run it up to a higher temp as a small dump load and maintain a normal temp if someone takes a 8pm shower or I run the dishwasher at night.
I've been eyeing the 80 gallon Stiebel Eltron from AltE, it has an input that allows a second, higher water temp set point on command all I would need is a relay/dry contact. But, it doesn't support any data out. So, I could allow the higher temp, but I couldn't see what was happening with the water temp. In reality, that's not important, but I like data.
I recently bought the Rheem heat pump water heater and like it so far, I run it in heat pump mode but if you have a family it will need to use the heating elements. I also installed 5 Pioneer mini splits but only needed to use a 3/4 ton unit to heat my 1600 sq feet but I have R60 walls and ceilings. I live in Arizona but it was getting down into the 20s at night. Love the mini split, don't know its even on. Running it all off grid on an EG4 battery rack.
