Best Ducted Heatpump

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#2254697 9-Jun-2019 09:50

dt:

Depending on what your house configuration is like, Id highly advise you have them put the outdoor units as far away from any bedrooms or anywhere else you enjoy quite - maybe beside the garage? as you can hear them in the evening, but I am a peace and quiet nut so may not be to much of an issue for everyone else :)

This is very important. Most ducted systems have noisy outdoors units. They're designed with sprawled suburbia in mind and not the densely packed houses New Zealand has. People have been ordered against using their heat pump by their council because of the noise from a whole house system.

Check the db specifications very carefully and don't confuse sound pressure db with sound power db. Don't place it near a bedroom and think about the neighbours. Laminating nearby glass windows will reduce sound intrusion from the heat pump unit. A quality low e glass like XCel will reduce heating needs.

Personally I would prefer to put the money of a ducted system towards making the build more along passivehouse lines so it doesn't need as much heating and cooling.

Paul1977

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#2255070 10-Jun-2019 09:42

Lots of good feedback.

We've all but decided that ducted is what we'll do (budget allowing), but we still appreciate the feedback about the downsides as it all helps to get the install right.

Our specific requirements would need at least 3 separate wall units if we went non-ducted, and cost-wise that is getting closer to the price point of ducted anyway. We dislike the look of wall units, and I find the noise of them annoying. So it's all pointing us in the direction of ducted.

We'll definitely look very carefully at the noise and placement of the outdoor unit, as the feedback here is pretty clear that they can be fairly noisy.

I'd be very interested to hear about installs that have gone wrong. Hearing about when things have gone wrong is often more helpful than hearing about when things go right.

@jnimmo does the Fujitsu not have the ability to control the damper natively over wifi/scheduling? Did you need to install the third party IntesisBox in order to control it in any way other than a hardwired switched?

@bfginger is it safe to assume that building a "passive house" would be considerably more expensive than a more standard house with a ducted heat pump? While I like the idea, the budget is already getting a bit stretched.

jonathan18

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#2255085 10-Jun-2019 10:05

Just a few general points, given there are a number of detailed threads on ducted heatpumps here on GZ which cover many of the things to be mindful of.

Agree that the noise of the external unit is annoying - I'd imagine an older house with single glazing and no wall insulation like our place will do a better job of letting through more of this noise, but do your best to get it located out of the way (near the garage perhaps, away from windows) and ensure it doesn't transmit too much through its contact with the house.

When we put in our unit a few years ago, only one brand (Daikin) provided built-in zone control; all other brands required an additional control panel for this. Not sure if this is still the case. The main advantage of the single approach is timers can be set to heat/cool specific zones (and similarly control zones via the internet). And, yes, getting the zones set up correctly is a complete dog, and requires skilled operators. See my last point.

Location of sensors is critical - I see someone above has theirs working ok with only using the return duct sensor, but this was a complete nightmare for us, leading to a variation in room temperature of over five degrees! (3m stud part of the problem, but doubt it was all). Have a sensor in each of the zones (if you have them), as there's simply no point trying to measure the temperature of an area that's not even being heated/cooled! (Not that our installers seemed to understand that.)

And that very last sentence is my biggest piece of advice - make sure you trust your installers. Get recommendations from others (as you are here, I know), make sure they've done a decent number of home-based ducted systems, and talk to some customers to see how they found it. Don't go for the lowest price, unless that's supported by other evidence that they know what they're doing...

In the end, it's totally worth it and, even with our system still not operating as well as it should be, I don't regret it. Nothing like having a house fully heated without any hassle.

(But, yeah, agree that the ideal is a passivhaus-type design that requires as little additional heating/cooling as required - that's what I'd be wanting to do if/when I get the opportunity to undertake a new build.)

bfginger

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#2255528 10-Jun-2019 20:21

Paul1977:

@bfginger is it safe to assume that building a "passive house" would be considerably more expensive than a more standard house with a ducted heat pump? While I like the idea, the budget is already getting a bit stretched.

It's a formal standard that requires climatic modelling, air tightness, testing and certification. I don't know if I'd want to go that far but most of the benefits can be realised without those. New Zealanders build to code and that code and general attitude in the industry isn't very good so it doesn't take much effort to go above it.

Does a house have R2.8 wall insulation? R4.0 thick wall? Thermally broken windows? XCel or similar grade low e glass? Edge insulated slab? Heat recovery ventilation system with summer bypass? Usually the answer in New Zealand will be no.

New builds can also suffer from severe overheating because of bad design.

jonathan18

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#2255541 10-Jun-2019 20:41

Really interesting interview on Nat Rad a few months ago with a passive house builder (and only NZ certifier). He argues it's not a huge amount more in build costs to take this path - and the argument is you'll generally make it up over time in lower running costs.

Personally, my sense is that, despite family size reducing, NZers have gone crazy-big in the size of new houses (or completely the opposite!), and that additional cost in going passive house design could be made up by simply shrinking the floor area. And I don't think one needs to go all-out (including getting the certification), as even adopting some of the techniques can surely only help.

Here's the link to the interview: https://www.rnz.co.nz/national/programmes/ninetonoon/audio/2018681402/passive-houses-warm-dry-and-sustainable-so-why-not-more

That also includes a link to a PDF book on passive house building in NZ - https://sustainableengineering.co.nz/ph4nzwarmhealthyhomes/

Kickinbac

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#2255573 10-Jun-2019 21:21

Here is a good blog on problems with ducted systems.

https://newenergythinking.com/2018/10/20/dont-use-ducts/

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#2257626 13-Jun-2019 21:29

We have a 14kw ducted system in our 220m2 home.

IT IS THE SINGLE BEST ACCESSORY WE PUT IN THE HOUSE.

ducted is AWESOME. it puts the heat/cool into the rooms not the hallways. I can't emphasise that enough.

The main indoor unit is up in the ceiling above one of the kids bedrooms and you can't hear it.

Our one is 5 years old now so I don't know what the latest controls are like but ours is straight out of 1983....it doesn't even have a back light FFS... So don't even think about fancy phone apps.. Lol.

Don't even think about wall mounts. Ducted all the way.

floydie

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#2257715 13-Jun-2019 21:49

Oh and don't believe the haters saying that ducted is less efficient.

The fact that it puts the air IN every room and circulates it throughout the house makes the required set temp lower.

We run ours about 18-21degrees heat during the day and 17/18 at night.

Summer is cooling at 21 to 23 degrees depending on mood.

We have adjustable vents (that can be set to auto) and it didn't take long at all to "balance" the airflow/heat throughout the house.

Installation is key our setup is ducted and returned in such a way the living is a couple degrees warmer than bedrooms which is perfect.

Of course it works great as a big fan too so you can just run it as a big hrv if you've got a hot and cold side of the house

mattwnz

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#2257807 14-Jun-2019 00:47

bfginger: Personally I would prefer to put the money of a ducted system towards making the build more along passivehouse lines so it doesn't need as much heating and cooling.

Somewhat difficult though in an urban environment, where sun maybe blocked by neighbours. Especially low angled winter sun, which you want to heat a thermal mass like a concrete slab.

Jase2985

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#2257813 14-Jun-2019 05:36

floydie:

Oh and don't believe the haters saying that ducted is less efficient.

you cant say that, because it IS less efficient, it looses heat though the ducts where as a floor, highwall or cassette one doesnt. there may not be much in it but you cant argue against physics.

thats not saying dont get one but just be aware of heating and cooling losses through the ducts. so maybe spend a little bit extra on getting more insulated ducting.

Paul1977

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#2257923 14-Jun-2019 09:25

mattwnz:

bfginger: Personally I would prefer to put the money of a ducted system towards making the build more along passivehouse lines so it doesn't need as much heating and cooling.

Somewhat difficult though in an urban environment, where sun maybe blocked by neighbours. Especially low angled winter sun, which you want to heat a thermal mass like a concrete slab.

I've done a little reading over the past few days, and what you are talking about is passive solar heating which is just one aspect. I think the main aspects of a passive house are the insulation and air tightness so once it's at the desired temperature it's easy and cheap to keep it there.

I'm certainly going to get pricing for upgrading of insulation and glazing and adding fresh air with heat recovery to the mix. I think going the route of a full blown certificated passive house would be extremely expensive in NZ, but following some of the principals might be manageable - if it makes financial sense.

The problem is I just don't know how to work out if the increased build costs would ever be recouped in power savings.

If it adds $100 per month to the mortgage payments, will it be saving $100 per month in power? If not then I probably can't afford it.

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Paul1977

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#2258061 14-Jun-2019 11:21

A lot of suggestion about passive housing, so I have started a thread specifically about passive housing technologies here.

rphenix

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#2258177 14-Jun-2019 13:47

timmmay:

I have a 10 year old high wall Daikin and a 6 year old high wall Fujitsu Nocria - not ducted. The Fujitsu is much louder, more efficient according to the specs but louder. I like the Daikin better.

This probably isn't that helpful sorry.

The Fujitsu Ducted units are quiet you have to listen for the slight wind noise near the outlet that or pop open the window and listen for the compressor. We installed one about 18months ago 3 room ducted no seperate zone control can simply wind down the diffuser in a particular room if you want to reduce the heat or cooling for it.

mattwnz

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#2258184 14-Jun-2019 14:03

Jase2985:

floydie:

Oh and don't believe the haters saying that ducted is less efficient.

you cant say that, because it IS less efficient, it looses heat though the ducts where as a floor, highwall or cassette one doesnt. there may not be much in it but you cant argue against physics.

thats not saying dont get one but just be aware of heating and cooling losses through the ducts. so maybe spend a little bit extra on getting more insulated ducting.

How much heat / cooling is actually lost though, especially when compared to a multi indoor unit piped around to the same areas? Ducted only works if you also have a good amount of roof space for the wide insulated pipes, so they aren't suitable for all, including low pitched or skillion.

AndrewTD

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#2258291 14-Jun-2019 15:56

We have a Daikin ducted system in our house - installed a few years ago. I too am now a big fan of ducted systems. It is perhaps the best home improvement we have made. Well worth the cost.

Here are the lessons I have learned:

1. It keeps the whole house warm/cool as required, easily and the running costs are not too bad. We love having it.

2. I have installed a couple of extra sensors - one in the living room, and one in the master bedroom. Using the "internal" sensor in the unit in the ceiling wasn't ideal. I also have zones defined, e.g. living/kitchen as one zone, and two different zones for bedrooms.

3. The Wifi component of our Daikin unit is poor at best. I since found out that the WiFi on this Daikin unit was their first go at WiFi. They used a third party supplier who has since gone bust. So no updates etc. The effect on me is that sometimes the controller loses connectivity and it can take days for it to reconnect. Power resets seem to have no effect om this process. The phone app does however work well and reliably on both android and ios - but you can't select the sensor from the app. Because of all this I would probably choose a different brand If I had to do it again.

4. There is one room in our house where I would consider putting a stand-alone unit. It is a small bedroom and has a big TV and game console in it, so it can get very hot in there, even when the rest of the house is cold and needs warming.

5. I first selected a good installer (good reviews etc) and then asked them to quote various units. I think this is the better way to go, as opposed to selecting a brand and then finding an installer for it.

[As an aside, I install installed a wood burner, because I like fires, and so that I could have some heating if the power goes out for a while - e.g. after an earthquake etc.]

kind regards Andrew TD

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