Installing a ducted heat pump and building my own zone control

Forums › Gadgets, robotics, home automation, electronics (including wearables) › Installing a ducted heat pump and building my own zone control

Obraik

2123 posts

Uber Geek

#303172 21-Jan-2023 12:35

I'm not sure if this post fits best here or the DIY forum but I figure it's probably better here due to the focus on Home Assistant and automation.

Anyway, I'm currently in the process of having my first home built and have opted to go with a ducted heat pump system. Zone control seems like a no brainer and the contractor has given the option of a system called MyAir. TBH, I'm not overly enthused by the system. I'm not keen on the idea that it relies on an Android tablet wired to the wall (what happens when the tablet dies? What happens when the tablet stops getting Android updates? etc) and I don't like how proprietary it all is.

I'm pretty keen on Home Assistant for smart home and home automation stuff and have been using it for a number of years now, with a number of ESP based devices and sensors scattered around the house running ESPHome (a mix of commercial items reflashed with ESPHome or built from scratch). It wouldn't be beyond the capabilities for my partner and myself to build something up that is controlled by Home Assistant to achieve similar capabilities of the proposed MyAir system.

What I was considering is just telling the contractor to flag MyAir but to install the dampers that we can then set up at a later date. I'm not sure how open they will be to such a request given that it's in conflict with the system they're trying to sell us. I'm also mindful of what impact this might have to any warranties with the heat pump unit itself. Is this a dumb idea?

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1 post

Wannabe Geek

#3025145 21-Jan-2023 13:56

We had a ducted Fujitsu system installed a couple of years ago which came with anywAiR which is just a rebranded name for the Advantage MyAir system. I have managed to get it into Home Assistant using the Advantage Air integration and then used the Homekit integration to add to Apple Home (make sure to set the tablet to have a static IP via router). We can see current room temperature, temperature sensor signal strength and damper opening percentage.

As for the tablet itself, it does have some drawbacks. It does seem pretty locked down settings wise and doesn't use the usual android update method, rather a 3rd party type app which shows the current version being v1.0.0, Android 10 and with the device itself showing the last security patch being May 2020. When checked for updates there are none available.

Overall we are really happy with it when comparing it to our old heating system as we find it so easy to set up schedules and control on a day to day basis using the tablet on the wall and our phones.

I think it is a good idea to ask so you at least get past some potential security issues but it may create issues if new homeowners come in and something stops working. As for warranty the could cover all the other equipment however it might be harder to prove.

Obraik

2123 posts

Uber Geek

#3025154 21-Jan-2023 14:11

I did see you can add it to Home Assistant but it's still dependant on the tablet being alive as the integration talks to open ports on the tablet, which seems a bit yuck. It also seems a bit of a waste to spend all that to get the whole system when I intend on mostly using Home Assistant to control it - I might as well cut out the middleman.

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SpookyAwol

626 posts

Ultimate Geek

#3025186 21-Jan-2023 15:14

Im using a Daiken system with a wireless controller that is supported by Home Assistant.
Have you considered looking at a brand / model where there is existing support for HA?

Handle9

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#3025219 21-Jan-2023 16:17

It's not a dumb idea providing you go in with appropriate expectations. Zone control kits are all Frankensteins anyway, ducted units aren't designed to work with them. You don't get good temperature control but you can get some control. Bear in mind you are taking a system designed to run at a constant volume so the air has to go somewhere, you can't turn it right down.

Your installer shouldn't have a problem supplying and installing the dampers, they would generally be third party anyway rather than part of the kit. If they refuse get another supplier. I'd just tell them to install them now as you might want to do something in the future.

Damper actuators are freely available and not super expensive, although more costly than you might think. For these applications they are usually 2Nm 3 position (also called 3 point floating) actuators. You need 2 relays per actuator if you want to modulate, 1 if it's just open/closed. If it's DIY go for 24VAC actuators. You'll need a transformer anyway.

Your warranty shouldn't be affected unless you go under the minimum airflow or maximum pressure rating of the unit. If you do that you can break things although it's more likely to be the ductwork.

The biggest trap is over pressurising the unit by closing the dampers too much. You can also freeze the coil by doing this if you are under minimum airflow.

tweake

2391 posts

Uber Geek

#3025246 21-Jan-2023 18:15

no comment on home automation, i don't know how far your along your build but with ducted heat pumps try to get it installed inside the envelope if at all possible. your heat pump will love you for it.

that may mean lifting the insulation/air layer to the roof line, or creating an insulated channel down the centre of the house. things work a whole lot better when they are at room temps not outside or ceiling temps. plus duct leakage being on the inside of the house is a major plus.

don't forget ventilation hook up.

timmmay

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#3025291 21-Jan-2023 20:10

Have a read of this thread. My first choice would be any zoned system with individual room temperature control that is provided by a single manufacturer - e.g. if Daikin or Fujitsu sell a system that does everything, consider that first. Next, the Airtouch5 is a good system, far far easier than doing it yourself. I have Airtouch4 and it works pretty well. I use Home Assistant I have the Airtouch automated well, including direct damper control in some circumstances, but you might not need that. I use a this integration (forum link). If you get the Airtouch get the "ByPass Mode". Read the link for what a spill zone is, bypass mode basically replaces that with a damper that links the heat pump output to the input so there's no spill. The Airtouch tablet will last as long as it lasts, when it fails, buy another from Airtouch - I had one replaced under warranty as WiFi wasn't great, just replaced the existing one with the newest model and it worked great. Android updates are irrelevant, while it's a standard tablet use it as a single use device.

A friend has MyAir and has had a LOT of trouble with it. Don't get it.

I wouldn't do a DIY system. Too much hassle, no support.

Agree with tweake to try to get the ducts inside the insulated envelope, difficult if not designed into the system. If not get the most highly insulated ducts you can, which is probably R1.0, instead of the standard R0.6.

Handle9

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#3025311 21-Jan-2023 22:17

tweake:
no comment on home automation, i don't know how far your along your build but with ducted heat pumps try to get it installed inside the envelope if at all possible. your heat pump will love you for it.

that may mean lifting the insulation/air layer to the roof line, or creating an insulated channel down the centre of the house. things work a whole lot better when they are at room temps not outside or ceiling temps.

This is one of those ideas that sound good but the flow on effects are tricky. You are either creating possible water problems by raising the insulation to the roof line or you are adding significant height to the building.

Generally ducts inside the envelope are rigid and built into bulkheads rather than flexy ducts. It adds significant cost to the build for a slight efficiency gain. In temperate climates it’s a nice to have with minimal benefit.

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Obraik

2123 posts

Uber Geek

#3025318 22-Jan-2023 01:06

SpookyAwol:

Im using a Daiken system with a wireless controller that is supported by Home Assistant.
Have you considered looking at a brand / model where there is existing support for HA?

The heat pump unit that is being supplied is a Daiken, but they're not intending on using a Daiken controller for the zone control. As far as I'm aware, the only system that they install for this is the MyAir system. I don't think there's much choice when it comes to going with a different heating contractor as that is who the builder works with.

Handle9:

It's not a dumb idea providing you go in with appropriate expectations. Zone control kits are all Frankensteins anyway, ducted units aren't designed to work with them. You don't get good temperature control but you can get some control. Bear in mind you are taking a system designed to run at a constant volume so the air has to go somewhere, you can't turn it right down.

Your installer shouldn't have a problem supplying and installing the dampers, they would generally be third party anyway rather than part of the kit. If they refuse get another supplier. I'd just tell them to install them now as you might want to do something in the future.

Damper actuators are freely available and not super expensive, although more costly than you might think. For these applications they are usually 2Nm 3 position (also called 3 point floating) actuators. You need 2 relays per actuator if you want to modulate, 1 if it's just open/closed. If it's DIY go for 24VAC actuators. You'll need a transformer anyway.

Your warranty shouldn't be affected unless you go under the minimum airflow or maximum pressure rating of the unit. If you do that you can break things although it's more likely to be the ductwork.

The biggest trap is over pressurising the unit by closing the dampers too much. You can also freeze the coil by doing this if you are under minimum airflow.

Yeah, I'm going in with the expectation of decent control, not perfection. I'd also be adding some safety configs so someone can't accidentally shut all dampers while the unit is running. The idea was to use a multi-finned damper like this, which I think is the same unit used by the MyAir system.

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Obraik

2123 posts

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#3025319 22-Jan-2023 01:24

timmmay:

Have a read of this thread. My first choice would be any zoned system with individual room temperature control that is provided by a single manufacturer - e.g. if Daikin or Fujitsu sell a system that does everything, consider that first. Next, the Airtouch5 is a good system, far far easier than doing it yourself. I have Airtouch4 and it works pretty well. I use Home Assistant I have the Airtouch automated well, including direct damper control in some circumstances, but you might not need that. I use a this integration (forum link). If you get the Airtouch get the "ByPass Mode". Read the link for what a spill zone is, bypass mode basically replaces that with a damper that links the heat pump output to the input so there's no spill. The Airtouch tablet will last as long as it lasts, when it fails, buy another from Airtouch - I had one replaced under warranty as WiFi wasn't great, just replaced the existing one with the newest model and it worked great. Android updates are irrelevant, while it's a standard tablet use it as a single use device.

A friend has MyAir and has had a LOT of trouble with it. Don't get it.

I wouldn't do a DIY system. Too much hassle, no support.

Agree with tweake to try to get the ducts inside the insulated envelope, difficult if not designed into the system. If not get the most highly insulated ducts you can, which is probably R1.0, instead of the standard R0.6.

Thanks for the link, it was a good read. The unit we've been specced with is a Daikin so it's good to see you've had a good experience with it. I'm still on the fence of DIY vs just getting the MyAir system. The IT side of me isn't keen on the idea of a Android tablet that is critical to everything and can't easily be updated while requiring port forwarding to it for the native app to be able to connect to it externally. If I did go with it, I'd have it VLANed in its own little silo with bare minimum internet access and would rely on the Home Assistant integration that you linked to for external access.

Which is kind of what put me down the path of considering a DIY option. If I'm going to be controlling everything via Home Assistant anyway, why spend the extra on a system that would essentially just be acting as an inbetween translator when I could replicate that with Home Assistant directly?

The core system and ducting is designed into the house build so I'm not too worried about that part when it comes to the ducting being in the correct place.

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Handle9

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#3025327 22-Jan-2023 02:24

Obraik:
[
Yeah, I'm going in with the expectation of decent control, not perfection. I'd also be adding some safety configs so someone can't accidentally shut all dampers while the unit is running. The idea was to use a multi-finned damper like this, which I think is the same unit used by the MyAir system.

You won’t get “decent” control. You’ll get some states which will be ok and some which will be all over the shop. It’s the nature of the beast.

If you were doing it somewhat properly you’d have a unit with an EC fan and pressure control off the index duct. This would give you somewhat reasonable volume control, even without a volume sensor.

That’s not really viable in a domestic situation so you end up with a Frankenstein arrangement that sometimes works and sometimes is a mess. The dampers are useful even if you don’t use them for temperature control as they’ll let you balance the system which the installer likely won’t do.

timmmay

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#3025336 22-Jan-2023 08:14

I suspect you're underestimating the cost and effort of doing this yourself, and overestimating how much you will need to do in Home Assistant if you have the Airtouch. I considered the DIY solution and it turned out similar cost to buying the airtouch.

Airtouch doesn't need port forwarding, they have a cloud service so when you're outside the house their app works. I don't use the app any more though, I use a VPN to my house then my Home Assistant user interface. Happy to share that. Having an older version of Android doesn't matter for a single purpose device.

Once the Airtouch is installed with the bypass feature, the only thing you'll likely do in Home Assistant is on / off / mode / temperature scheduling which is pretty simple. You may not even do that, you may use the Airtouch features. I only started using HA for Airtouch as AT4 timer isn't great, but I think AT5 timer is better. You won't need / probably won't want direct damper control as AT works well.

MyAir on the other hand is not great. My friend had it installed but refused to pay for it until it worked correctly - I'm not sure if it's right yet but that took at least six months. It does something odd like monitoring one zones temperature at a time, concentrating on that room's temperature, then moving on to the next room. I'm not sure of the details but it sounds quite bizarre. He also said it blows quite strong cool / ambient air around when heating mode is turned off - though with Daikin it is possible for the installer (not the user) to configure the heat pump to turn all fans off when it's up to heat. I strongly recommend you fully understand that system before you purchase it.

If you get a damper system with no zone / temperature control you can have AirTouch added by another vendor later. They add controller in the ceiling, electric dampers, and a few minor bits. That works out more expensive as each vendor wants to make a decent profit, whereas if a single vendor is installing heat pump and AT it usually works out cheaper.

In your place I would check with the builder and then get a new air con vendor in. Shouldn't be a big deal.

SpookyAwol

626 posts

Ultimate Geek

#3025348 22-Jan-2023 09:14

Obraik:

The heat pump unit that is being supplied is a Daiken, but they're not intending on using a Daiken controller for the zone control. As far as I'm aware, the only system that they install for this is the MyAir system. I don't think there's much choice when it comes to going with a different heating contractor as that is who the builder works with.

Im using these, so its a shame if they cant supply them. They do work for you and you pay the bills?

Zone Controller:
BRC230Z4

Wireless adaptor:
BRP15B61

mattenz

190 posts

Master Geek

#3025353 22-Jan-2023 09:34

I'm currently doing similar myself. While I install the ducts, it's mainly on my desk though

I've got 24V damper actuators from Aliexpress (get the ones that flip a switch at each extreme), then DIN-mounted 24V power supply, ESP32 with Fujitsu integration, an ESP32 RS485 IO expander.

Dampers are almost always a good idea for balancing, just make sure that the rods extend a good 50mm (that might rule out some premade plastic parts, but easy for galv). A galvanised one plus actuator from Aliexpress will probably end up way cheaper than what you linked.

Modern ducted units here in NZ have multiple fan speeds (might even have an EC fan), they're not designed for 'constant volume'. That said, you can only shut off so much, and you might want to monitor static/total pressure, comparing it to manufacturer specs.

tweake

2391 posts

Uber Geek

#3025420 22-Jan-2023 10:49

Handle9:
tweake:

no comment on home automation, i don't know how far your along your build but with ducted heat pumps try to get it installed inside the envelope if at all possible. your heat pump will love you for it.

that may mean lifting the insulation/air layer to the roof line, or creating an insulated channel down the centre of the house. things work a whole lot better when they are at room temps not outside or ceiling temps.

This is one of those ideas that sound good but the flow on effects are tricky. You are either creating possible water problems by raising the insulation to the roof line or you are adding significant height to the building.

Generally ducts inside the envelope are rigid and built into bulkheads rather than flexy ducts. It adds significant cost to the build for a slight efficiency gain. In temperate climates it’s a nice to have with minimal benefit.

not really.

insulation at the roof line is a normal building practise with no water/moisture issues. its done on a lot of kiwi houses. my previous house had that. the hard part is doing the air barrier, tho the trade off is the ceiling is no longer the air barrier so we don't have to be to concerned with air tightness on the lighting and grills etc. any air leaking through the ceiling is simply going to another 'room' of the house.

the height of the building doesn't change, or is a minor change (0-4" depending on how its done).

putting ducts inside the envelope doesn't change what they are made of, they are still hidden away.

yes it does add cost and it does increase the interior volume of the house which increases the volume to be conditioned. but doesn't really change the load much as the external surface area doesn't change much unless its a really steep pitch roof.

but there is also big benefits. the ceiling space now becomes a great fully conditioned storage space (or if designed right becomes another room), no mice/insects/pests etc getting in (as its sealed from the outside), the equipment lasts longer and runs better. less condensation issues. as duct leakage is now inside the home its no longer pumping air to the outside of the house making the house negative pressure and the house sucking in humid air (ie it maintains positive pressure from the ventilation system). any duct leakage is simply going into the house.

timmmay

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#3025424 22-Jan-2023 11:04

Two other things to consider regarding purchase vs build:

Wife acceptance factor. If something isn't working right and you say 'I need a couple of days to change it in home assistant' wife may not be happy
Resale: if you ever resell the house having a tablet on the wall to control the air conditioning system is a heck of a lot better than saying "you have to learn and use home assistant to control the system".

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