Ducted heatpumps - Panasonic vs Mitsubishi

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iceteap3

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#310531 28-Oct-2023 22:34

Hi everyone,

As summer starts ramping up in Auckland, we're looking to put in a new heat pump to keep us from roasting in the upcoming el niño summer.

A little background on our place in west Auckland, we've here been here for 3 years, the house is a 1960's build, insulated (wall & ceiling) but no heating devices other than an old fireplace which we dont really use. Floor area is approx 100m2, 2.4m ceilings (3 bedrooms with lounge & dining area) so not the largest house. The house has quite a few large single glazed windows facing the sea so winters are freezing and during the summer the sun beaming into the bedrooms/lounge turns it into a green house.

We've had three HVAC suppliers through to provide some pricing and so far the choices seem to be between Panasonic and Mitsubishi models. All three have calculated an approx 10kW load so have recommended 12kW and up systems. Front running offers so far seem to be the following:

Panasonic SU-140PE3E5 HZ - 16kW heating, 14kW cooling (inc WiFi, 7 outlets, r0.6 ducting (asking them to increase to R1.0)) - approx. 12k

Mitsubishi PEA-M125GAA - 14kW heating, 12kW cooling (inc WiFi, 7 outlets, r0.6 ducting (asking them to increase to R1.0)) - approx. 13k

From all my research it seems like to following points seem to stand out.

Panasonic:

lots of reviews spread across good and bad experiences
Decent ability to turn down to a lower/higher kw for heating and cooling (range of 3.3kW-18kW heating for the 14kW model) and three fan speeds
louder at the max fan speed (51dBA at the high fan setting while outputting a max of 1002 l/s)
The outdoor unit is nosier (rated at 54dBA (Mitsi at 52))
Wifi app is reportedly not as good as the Mitsi

Mitsubishi:

Cant quite turn down to as low as the Panasonic (range of 5kW-16kW heating for the 14kW model), only has 2 fan speeds, high and low (no auto) which could mean its constantly blowing air. outlined here https://www.geekzone.co.nz/forums.asp?forumid=141&topicid=272078
Seems quieter at the high/low fan speed range (42-45dBA) although there are the odd reviews saying its extremely loud https://www.productreview.com.au/listings/mitsubishi-pea-m100125140gaa
Maintains a 1000 l/s flow at high fan speed
App supposed to be quite good.
not as grunty as the panasonic which may be a factor with lots of windows in the house (and to be honest id like to just be able to blast it on the cold/hot setting to very quickly cool/heat down the place )

None of the quotes offer zoning or fresh air (we don't feel like its needed (no condensation issues and its a small flat house) and are trying to keep the cost down but we may ask for a damper to be added so that we can separate the lounge from the bedrooms)

I guess im trying to understand whether the small technical details really translate into real world annoyances (i.e fan speed and noise) or whether im just stuck in analysis paralysis over-anylysing the spec sheets for these units. Would be awesome to get some feedback from anyone who has been through this before.

thanks !

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614 posts

Ultimate Geek

#3153225 29-Oct-2023 07:55

We had a PEA-M100HAA (splittable roof unit) installed 2 months ago. It’s great. We’ve never needed to turn the fan up higher than the lowest speed, it’s very effective (heating and cooling). Noise not an issue from either duct outlets or the inside unit in the roof. Don’t put the outside unit right outside a bedroom as it makes a bit of noise (applicable to any brand). App control is great and home assistant integration is simple and seamless. We have 4 fan speeds available.

timmmay

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#3153228 29-Oct-2023 08:16

Have you read my ducted heat pump advice thread? I'm not an expert, but I've had two ducted heat pumps in the same house.

Re your last question "analysis paralysis", you're not overthinking this. Ducted units are complex. If anything you need to read more widely about them before you make a decision, ideally talk to a few people who have a ducted unit installed. Be a little wary of advice from people who don't have a ducted unit or similar experience.

Here's some general thoughts:

I would not have a ducted heat pump without individual zone temperature control - I would much rather have individual high wall / floor units. Rooms heating and cooling requirements vary constantly, you'll either overhead or overcool the room. If you don't have zoning with temperature control you have to set the dampers and leave them there, at a set ratio of air going to each room. If you set the dampers for a sunny day that puts a lot of cool air through the rooms on the sunny side of the house, but not much through the shady side. When you then get a cold day you're overheating the rooms on the sunny side, which will usually be warmer even on a colder day. I had my first ducted heat pump removed partly because of this, partly because it was very loud. You would be much better off with individual / split units than ducted without zone temperature control.
With my first unit without zoning, I was up into the ceiling twice a day to try to optimise the manual dampers. It's impossible, because the damper positions needed change based on weather. After a few weeks of frustration with this, a loud unit, and weird smells, I had that unit removed. It cost 50% more for a zoned unit, but it's worth it.
Mitsubishi over Panasonic every time, no question. Quality and noise levels. Even though minimum output is lower on the Panasonic, based on my experience (which is a few years old now) I wouldn't touch a Panasonic ducted unit.
Ducted heat pumps require return paths for air. That means vents in walls or doors, some will recommend undercut doors but I don't like that as the cut needs to be 1-2cm to get enough airflow. Look at the links in my thread.
Multi-split units or even individual units in rooms can give you more control, fewer holes in the house as there's no return required, fewer breezes, and may be cost effective. If you go with multi-split and need more than one outdoor unit, group them based on sun exposure of the rooms so one can be heating while the other is cooling - we do that quite a bit in spring / autumn. Try to avoid the installers oversizing everything - the smallest indoor units are probably sufficient for bedrooms for example, because they can run constantly and run on a timer.
Ducted systems require more experience to install - even firms who are high volume doing ducted units might not do a great job.
See if you can find a supplier than will consider Daikin and Airtouch, or Mitsi and Airtouch, if you want to go ducted. Go to the Daikin website, look at the ducted area, somewhere there's an option to recommend an installer.
Make sure your units can be controlled by Home Assistant, for future proofing.
Ducted units are more difficult to program. They require more automation, and they often have weak automation capabilities. That's why I use home assistant.
You don't really want to turn heat pumps on and off to "blast them". Use the timer, set it to cool before you get home, use any remote control capabilities that some apps provide, or use a VPN with the app.

Here's some thoughts specific to your situation:

Oversizing heat pumps makes them cycle more often, which wears them out more quickly. If they calculate you need a 10kw unit, get a 10kw unit. It's also more comfortable to have a constant flow than stop / start. Our heat pump is oversized, partly because we don't always have all the zones on.
Minimum heat / cool output is pretty important. Say you only have one room that needs some cooling, or a little heating as the house is mostly up to heat. If your minimum output is 5kw and you really only need 1kw that 4kw will need to go somewhere. Read up on spill zones in my other thread.

Happy to answer any other questions you have.

tweake

2391 posts

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#3153236 29-Oct-2023 09:36

iceteap3:

All three have calculated an approx 10kW load so have recommended 12kW and up systems. Front running offers so far seem to be the following:

Panasonic SU-140PE3E5 HZ - 16kW heating, 14kW cooling (inc WiFi, 7 outlets, r0.6 ducting (asking them to increase to R1.0)) - approx. 12k

Mitsubishi PEA-M125GAA - 14kW heating, 12kW cooling (inc WiFi, 7 outlets, r0.6 ducting (asking them to increase to R1.0)) - approx. 13k

this i absolutely hate. would you like fries with that?

if it requires 10kw then install 10kw. not 12kw and up. if anything your better to undersize the system than to oversize it. with undersized there will be a few days a year where its not going to keep up and you can put some more clothes on, but it will run efficiently a lot of the time. with oversized it will never/seldom run efficiently.

they are overselling simply to line their own wallets at your expense.

tweake

2391 posts

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#3153237 29-Oct-2023 09:54

timmmay:

Ducted heat pumps require return paths for air. That means vents in walls or doors, some will recommend undercut doors but I don't like that as the cut needs to be 1-2cm to get enough airflow. Look at the links in my thread.

Multi-split units or even individual units in rooms can give you more control, fewer holes in the house as there's no return required, fewer breezes, and may be cost effective. If you go with multi-split and need more than one outdoor unit, group them based on sun exposure of the rooms so one can be heating while the other is cooling - we do that quite a bit in spring / autumn. Try to avoid the installers oversizing everything - the smallest indoor units are probably sufficient for bedrooms for example, because they can run constantly and run on a timer

You don't really want to turn heat pumps on and off to "blast them". Use the timer, set it to cool before you get home, use any remote control capabilities that some apps provide, or use a VPN with the app.

Here's some thoughts specific to your situation:

Oversizing heat pumps makes them cycle more often, which wears them out more quickly. If they calculate you need a 10kw unit, get a 10kw unit. It's also more comfortable to have a constant flow than stop / start. Our heat pump is oversized, partly because we don't always have all the zones on.
Minimum heat / cool output is pretty important. Say you only have one room that needs some cooling, or a little heating as the house is mostly up to heat. If your minimum output is 5kw and you really only need 1kw that 4kw will need to go somewhere. Read up on spill zones in my other thread.
Happy to answer any other questions you have.

air paths require a lot of work. the other issue here is house air leakage which creates issues with older leaky homes (like '60's)

one of the downsides to individual units is you may struggle to get units small enough for small bedrooms common with older homes. eg the required size for one of mine is 1.5kw.

agreed, you want heat pumps to run all the time rather than "blast them". the "blast them" approach is a hack because the house is so low quality it costs to much to heat/cool properly.

oversizing is not really about wearing them out, its about efficiency. ever time it restarts it wastes energy. if its to big for the coldest day, then its massively to big for the partly cold days that you get MOST OF THE TIME.

the lower the output it can go the better because thats the most commonly used range so it will keep running instead of turning on/off. even a variable will actually turn on/off quite a lot. most common usage is at part load, you only use full load on those few max cold/hot days a year.

Jase2985

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#3153406 29-Oct-2023 15:24

tweake:

but it will run efficiently a lot of the time. with oversized it will never/seldom run efficiently.

im sorry but thats simply not correct with modern inverter heatpumps. 2kw oversize on a 10kw uint is only 20% its unlikely to put it outside its efficency zone when you slow it down to its minimum setting.

Sideface

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#3153413 29-Oct-2023 15:53

I can give an unbiased opinion ...

Our big old single storey house has two heat pumps - a Panasonic and a Mitsubishi, both more than 10 years old.

Both work well in the Wellington climate.

I prefer the Mitsubishi because it is remarkably quiet (as advertised).

If and when I need to replace either if these units, I woulds choose the Mitsubishi, without hesitation.

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tweake

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#3153414 29-Oct-2023 15:57

Jase2985:

tweake:

but it will run efficiently a lot of the time. with oversized it will never/seldom run efficiently.

im sorry but thats simply not correct with modern inverter heatpumps. 2kw oversize on a 10kw uint is only 20% its unlikely to put it outside its efficiency zone when you slow it down to its minimum setting.

when its need to output bare minimum say (the numbers are a bit bs its just an example) 3kw , the 10kw will run quite efficiently. the 12kw won't run at all, it turns off. with low loads, the bigger the unit the more it runs in on/off mode instead of variable. low loads is what you have most of the time, so it makes a big difference to the overall efficiency and running cost.

you still need to size correctly as oversizing makes them less efficient because they will run more in on/off mode in low loads conditions which is most of the usage.

edit: to add this is also why we do not size the units to the coldest weather.

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timmmay

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#3153451 29-Oct-2023 18:29

tweake:

when its need to output bare minimum say (the numbers are a bit bs its just an example) 3kw , the 10kw will run quite efficiently. the 12kw won't run at all, it turns off. with low loads, the bigger the unit the more it runs in on/off mode instead of variable. low loads is what you have most of the time, so it makes a big difference to the overall efficiency and running cost.

My experience using a ducted Daikin system with Airtouch 4 is the outdoor unit runs until all zones are up to temperature, the opposite with cooling. If the minimum power output is quite high all that happens is one zone gets overheated or overcooled - the spill zone.

Without an Airtouch I don't know for sure how it'll work. I think it mostly works on temperature at the return vent.

iceteap3

40 posts

Geek

#3153455 29-Oct-2023 19:06

ashtonaut: We had a PEA-M100HAA (splittable roof unit) installed 2 months ago. It’s great. We’ve never needed to turn the fan up higher than the lowest speed, it’s very effective (heating and cooling). Noise not an issue from either duct outlets or the inside unit in the roof. Don’t put the outside unit right outside a bedroom as it makes a bit of noise (applicable to any brand). App control is great and home assistant integration is simple and seamless. We have 4 fan speeds available.

Interesting that the splitable unit has 4 speeds while the single PEA unit has just 2 - Does your unit have an auto mode? Ive been reading that the fan on some Mitsubishi units runs at a constant speed (either hi/lo) and when the indoor temp is reached it continues to blow out air at the same fan speed except the compressor turns off. Sounds quite annoying!

If anyone else has a Mitsubishi PEAD/PEA, would be good to get your input

timmmay

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#3153456 29-Oct-2023 19:08

iceteap3:

Interesting that the splitable unit has 4 speeds while the single PEA unit has just 2 - Does your unit have an auto mode? Ive been reading that the fan on some Mitsubishi units runs at a constant speed (either hi/lo) and when the indoor temp is reached it continues to blow out air at the same fan speed except the compressor turns off. Sounds quite annoying!

I can't tell you about Mitsubishi, but Panasonic and Daikin both keep the fan running once the unit is up to heat. With the Daikin the installer can turn that off, it's not something a user can do.

tweake

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#3153460 29-Oct-2023 19:22

timmmay:

tweake:

when its need to output bare minimum say (the numbers are a bit bs its just an example) 3kw , the 10kw will run quite efficiently. the 12kw won't run at all, it turns off. with low loads, the bigger the unit the more it runs in on/off mode instead of variable. low loads is what you have most of the time, so it makes a big difference to the overall efficiency and running cost.

My experience using a ducted Daikin system with Airtouch 4 is the outdoor unit runs until all zones are up to temperature, the opposite with cooling.

thats fairly normal, roughly, but its not what we are talking about. what happens once its up to temp and the system is maintaining temp?

BuzzLightyear

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#3153465 29-Oct-2023 19:43

I live in west Auckland and have a Mitsi ducted PEAD M100 with 5 zones. Had it for a year and a half now and I would recommend it.

Firstly, read all of @timmmay's threads and guidelines. I found them super useful when picking systems and understanding potential issues. I was comparing Daiken to Misti and honestly not much in them IMHO but I did like the quietness of the Mitsi and the app.

I have mine set to auto and from memory there are at least three speeds if you did want to control manually but not sure why you would bother. When you switch on and they are blowing hard the outdoor unit can be quite noisey but once temp is reached it settles down very quickly - it's not bad, just something to keep in mind. Quieter than other A/C units I have heard. Important to setup properly and have the temp reading coming from the right places. Go for zone control, my household would have struggled if we couldn't turn on and off zones as not everyone wants heating/cooling. For the sake of such a big investment don't skimp on that.

We pretty much use it continuously in winter and use night setback to keep the temp cozy. In summer we schedule on/off time via the app and more often than not keep lots of zones off as no point cooling the whole house (whereas in winter we want the whole place toasty).

timmmay

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#3153466 29-Oct-2023 19:49

tweake:

thats fairly normal, roughly, but its not what we are talking about. what happens once its up to temp and the system is maintaining temp?

My Daikin / Airtouch gets up to heat then the outdoor unit turns off, except perhaps on the very coldest days of the year, when it keeps running. I expect that's because the minimum output of the unit is higher than the power required to keep the house up to temp. We have the ducted system only does lounge and bedrooms, the Kitchen / dining is on a highwall unit as it sometimes needs to run on a different mode from the rest of the house due to sun and such.

We have the Daikin indoor FDYA85AV1 outdoor RZAS85CV1, minimum heating output is 4.1kw max 11.2kw. On the coldest days it has no trouble keeping the whole house warm, but it would take a bit longer if we started it from cold. If I knew then what I know now I'd probably get the smallest ducted unit available at the time which takes the minimum output down to 3.5kw / 9kw. It would be nice if the scaled down further, to maybe 1kw.

BuzzLightyear:

I was comparing Daiken to Misti and honestly not much in them IMHO but I did like the quietness of the Mitsi and the app.

My neighbor's son owns a fairly large company that does a lot of heat pump installs, residential and commercial. When my neighbor wanted a heat pump the son put in Mitsubishi. That's a pretty good endorsement.

tweake

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#3153471 29-Oct-2023 20:30

timmmay:

tweake:

thats fairly normal, roughly, but its not what we are talking about. what happens once its up to temp and the system is maintaining temp?

My Daikin / Airtouch gets up to heat then the outdoor unit turns off, except perhaps on the very coldest days of the year, when it keeps running. I expect that's because the minimum output of the unit is higher than the power required to keep the house up to temp. We have the ducted system only does lounge and bedrooms, the Kitchen / dining is on a highwall unit as it sometimes needs to run on a different mode from the rest of the house due to sun and such.

We have the Daikin indoor FDYA85AV1 outdoor RZAS85CV1, minimum heating output is 4.1kw max 11.2kw. On the coldest days it has no trouble keeping the whole house warm, but it would take a bit longer if we started it from cold. If I knew then what I know now I'd probably get the smallest ducted unit available at the time which takes the minimum output down to 3.5kw / 9kw. It would be nice if the scaled down further, to maybe 1kw.

depends on what you mean by outdoor unit turns off. just the fan or the compressor as well? many will slow down and even stop the fan. i'm assuming here you mean compressor is turning off.

once the house is up to temp it only runs as much as it needs to maintain the temp. which means it will turn back on at some point as the house cools. all depends on how cold outdoors is and insulation etc. the fact that it only runs constantly on the coldest days of the year suggests its well and truly oversized. it will be running stop/start when its below the minimum output it can do. once it needs to output more than minimum it will run constantly. therefore if properly sized it should be running constantly (at minimum output) well before the weather gets close to the coldest days.

the downside of it only running constantly on the coldest days is all the "not coldest" days it runs on/off mode which is less efficient, and there is a huge amount more "not coldest" days than coldest days. so your system is only running efficiently a small amount of time.

i think there was a mention of a company displaying new models which are dual stage variables, so you can get a much wider range output.

timmmay

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#3153475 29-Oct-2023 21:44

By turn off, I mean the outdoor unit goes completely quiet. The entire outdoor unit turns off, fan, compressor, everything.

With the air touch 4, if I have a single room enabled and set to 21° it heats until it reaches 21.5°, the outdoor unit turns off, then turns back on when the room drops to 20.5°. That scales to multiple rooms. There's a setting that influences that behavior deep in the AT installer settings, on/off of the outdoor unit can be based on room sensors, return vent sensors, or something else I don't recall.

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