Ducted heatpump advice sought

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#1346231 17-Jul-2015 13:17

I've done the deed and signed up for the Daikin unit (with the cool 7" colour touch screen!) set up with two zones. I guess time will tell how well it will work in low temps.In the absence of any advice to the contrary we've elected to go with the standard vents rather than the downwards firing jet vents, though the installer said we can change them if the air flow doesn't work as promised.

I understand why one may go with the multiple outside units, but I'm happy this unit will achieve what we want it to.

Thanks for the advice offered by all.

timmmay

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#1346264 17-Jul-2015 14:14

Let us know how it works out, once it's been in a week or two, then again at the end of summer/winter. It's something I may do one day, but I'd want each room individually controlled.

Jase2985

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#1346292 17-Jul-2015 15:05

its all about dew point :)

Im keen to know how it goes also, as we are looking to get one once we renovate :)

elv

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#1346577 18-Jul-2015 00:10

timmmay:
elv: Daikin heatpumps work in low temperatures. Most of the ducted Daikin heatpumps are made in Australia. I don' know where the Panasonics are made. Even in PN you should be concerned about being able to be use in low temperatures. If you have a decent frost and outside freezes your house will be cold you will regret your decision if you didn't consider it. Heating should work when it is cold.

I'm not sure this post is entirely accurate, I'd like to see it backed up with references. Cold isn't really a problem, but cold + moisture can be. Heat pumps can work better in the deep south where there's little moisture than up north where it's cold but damp.

Some heatpumps don't work efficiently at lower outdoor temperatures below freezing point. They have a tendency to frost up the outdoor unit causing low heating efficiency.

Efficient Operation In Extreme Conditions

In extreme climatic conditions the quality of your heat pump comes to the forefront.
Daikin inverter heat pumps incorporate advanced technology designed to operate reliably and efficiently in even the most extreme temperatures. They continue to help keep you cool when temperatures soar as high as 46ºC, and warm when temperatures reach as low as minus 10ºC.

Source: http://www.daikin.co.nz/why-daikin/heating-cooling-guide

I have installed heatpumps for a company and also speak from personal experience. I live in the "deep south" and my own Mitsurbishi hypercore outperforms other heatpumps when it is really cold. Some heatpumps are constantly defrosting the outdoor unit.

From experience the Mitsurbishi Hypercore, Fuijitsu and Daikin heatpumps all have manufacturer specifications that indicate that they work efficiently at minus 10 degrees C. Practical experience has shown them to work well in cold conditions while some other brands perform very poorly in below freezing conditions. I do not have experience with Panasonic.

jonathan18

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#1346599 18-Jul-2015 06:51

Sure,will post an update here once the system's installed and working. They're doing it quite quickly (in less than two weeks' time), but we may have missed out on the coldest nights by then!

cantonascollar

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#1346853 18-Jul-2015 16:39

I am also interested in your experience with your system. I am in Dunedin and am about to start major renovations, with ducted heat pump system as part of the final set up.

How much is your system going to cost? Here in Dunedin, I have been quoted either $12k or $16k inc GST. I favour the $16k quote - the company seem to have a bit more of an idea about what is required, etc. I want the system to be ducted from the floor (we have tin ceilings, which the wife doesn't want to cut holes in), which will entail a little crawling around under the boards, but not impossible to achieve. Also, the quote includes a 18.5kW Daikin heat pump whereas the cheaper option is a Fujitsu. We are going to have two controllable areas, one of which is a large open plan kitchen dining area (70 sqm) and the other is the bedrooms.

jonathan18

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#1347068 19-Jul-2015 07:46

There's been some interest in the cost and details of the system we're installing, so here goes...

House is a 1920s 4-bedroom 160m2, insulated ceiling and under-floor.

All prices are for a system with eight ducts (as discussed above, some argue for jet-firing vents for 3m studs, others think they create drafts and are not needed - this company, the one we went with, says they'd use jet vents in ceiling heights over 3m, and these are typically used in commercial environments).

Panasonic S/U-140PEIR5 (14kW cooling / 16kW heating) = $10,600
Panasonic S/U-140PEIR5 with two zones = $12,000

Note: these prices don't appear to include the wifi control module, which I had requested be included in the quote.

Further, the zoning above is based on using a damping system that is completely separate from the heatpump. This is how they are typically installed, but as I've posted on above this also means there's minimal integration between the two systems, eg fan speed isn't reduced automatically when using less than all zones at once; also there is no remote controlling of the zoning possible - eg if the damping system is set so only particular zones are operating and the heatpump is turned on remotely there's no way of amending this. It is for the these reasons we looked at the Daikin 'Premium Inverter Plus' unit, which appears to be the only one on the market that can currently do this as a single unit.

Daikin FDYQ125SL (12.5kW cooling / 15kW heating) = $12,900
Additional cost for SkyFi (wifi/smartphone control) = $680

Daikin FDYQT125SL (as previous model but with zone control built-in, wifi/smartphone control built in, and the flash colour screen) and with two zones = $14,000
Cost of additional zones - $270 (I think this version of the controller will work with up to four zones, but it also can be got with eight).

So the difference between the two options above, by the time even just the wifi control is added, is less than $500 to provide for the two zones. Even if one didn't want zones initially, it may be worth looking at this model as the dampers can be added in later plus you'd get the wifi control built-in plus the colour touch-screen.

I also received quotes for the same models above from another company:
Daikin FDYQ125SL with the SkyZone controller: $14,200
Daikin FDYQT125SL with two zones: $15,200

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Jase2985

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#1347080 19-Jul-2015 09:01

does that include insulated ducts?

linw

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#1347113 19-Jul-2015 11:20

I'd be interested in your power bill before and after.

jonathan18

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#1347192 19-Jul-2015 14:40

Jase2985: does that include insulated ducts?

Yes - the installer confirms that all ducting is fully insulated.

linw: I'd be interested in your power bill before and after.

I'll be tracking usage carefully, and given we're with Flick this will be fairly easy to do (though I look forward to the ability to download usage).

The classic line is that people's bills often go up after installing a heat pump, despite the assumption they'll drop given the cheaper running costs, but I understand often people 1. run them set to a hotter temperature than necessary and 2. have them going longer than usual. I'm wary of the first (I don't like a hot house so will be running it at 18-20), and will look at ways of controlling the second. I'd imagine the electricity bill could get damn high if warming the whole house 24/7 so it'll be a matter of finding a balance.

That said, it's not like we haven't got to pay for heating already in the guise of gas, firewood, and some electric - it's just that all heating will be from the single source and it'll be heating a bigger space.

linw

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#1347386 19-Jul-2015 21:29

I will be switching to Flick shortly, when my smart meter gets installed. The Wells guy came to do it last week but cried off as it was raining and the meter box is outside! Scardy cat didn't want the leccy tracking through the wet!

Like you say, it is a fine balance between warmth and price. Good to hear from you post install.

meesham

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#1347461 20-Jul-2015 08:34

Thanks for sharing the prices, it's very much appreciated and gives me something to think about.

Kickinbac

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#1357316 2-Aug-2015 21:21

Heres a good question to ask when installing a ducted heat pump....
What is the R value of the flexible ductwork?
Most installers will use R0.6 but you can get R1.0 which will retain the heat you're paying for better. Remember all the ducting is above the insulation in the roof so is outside of the thermal envelope of the house. It most likely won't cost a lot to upgrade.

timmmay

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#1357413 3-Aug-2015 07:38

I always wondered if you could run more insulation over the ducting, maybe by laying it on the floor of the ceiling cavity.

jonathan18

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#1357548 3-Aug-2015 09:38

Sounds like good advice, and a pity I didn't have it a week ago when I could have checked and made the requested change if necessary! Our install happened last Wed/Thur, so no ability to change the ducting to a more insulated version (if it's not already - I'll check as to which they used, but my bet is they'll go with the lower level to keep the price down so as to increase the chance of winning the work).

Operation of the system has not been plain sailing, and I'd warn people to be careful before electing to install one of these new Daikin units. Seems flash, but it's not all what it seems underneath. For example, the controller is nothing but a pretty basic Android tablet (running 4.3 I think?) in a plastic casing; it even requires a wall wart that we weren't warned about (looks weird/takes up a socket). More fundamentally is that it uses wifi to connect the controller and indoor unit - ie, there is no physical cabling between the two. This is the first of these units that the installer had put in, and they struggled to sort the wireless aspects out - and the instructions were crud (as is the owner's manual).

Twice the connection between the indoor unit and the controller has been lost - the first time (the day the install was finished) we had no idea how to solve the problem, so we had no heating. The second time I'd been instructed on how to sort it, but this required accessing a wired controller connected to the indoor unit (which we have poking out from the manhole in case we need to use it again). I think those without ok IT chops would totally struggle to deal with such a problem if it came up, meaning that they'd be without heating.

The controller can be set up to connect directly to the AP of the indoor unit, but this means there's no ability to control the heatpump remotely (which was one of the reasons we elected this model in the first place!). To enable this both devices need to be connected to our router, which then introduces another possible point of failure (or confusion for others).

I've also got a couple of questions regarding its operation, but I'll stick these in another post.

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