Ducted heatpump advice sought

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#1404102 12-Oct-2015 09:02

Hey there,

While I did say earlier in this thread I'd report back on the performance of (and cost of running) the new ducted system, we've had on-going issues with the installation. Given the effort put into fixing these, I won't expend more in describing them! That said, we've had probably an 80% solution running for most of the time since installation (forced from say a 40% solution as of initial installation, and only pushed up as a result of a lot of pushing). Suffice to say that the advice in this thread and others about the problems with designing and installing ducted heatpumps, especially retro-fitted into older homes, is completely correct! I think once we get this issue sorted I'll be generally happy with the system, but to get to that point has been like pulling teeth. Running-cost-wise, it's actually been ok; given we run it most of the time to heat the whole house and have often run it at night to keep the bedrooom side warm, it's been totally acceptable.)

Anyway, I was hoping to get advice on what is hopefully the last outstanding problem, which is poor hot air distribution in those rooms with the higher (3m) stud. I had concerns about this from the beginning (see my original post), but in the end was persuaded by the company we went with to go with these standard diffusers:

We've had the classic issue in these high-stud rooms with stratification, with air so much warmer at ceiling height , warm air patches at doorways, and cool patches like the front hall (which has a vent) that never seem to warm up. Following some advice (from here I believe) I've taken out the central 'plug' from the diffusers to see what happens, and the results have been astonishing. While there is now a decent current of air that can be felt directly below (not ideal), all rooms with this 3m stud are now evenly warm both horizontally and vertically, and there are few if any significant cool patches.

So clearly we need to replace these diffusers with ones that allow air to be fired downwards. One ducting company recommended the downjet below, but this doesn't allow adjustment of angle so I'm not so keen as I also want to be able to have the choice to be able to fire the air sideways, which would be more appropriate for cooling in summer.

So, I'm wondering about vents which offer a level of control (either manual or automatic) for angling the air. Thus far I've only found the following (which is the one I think one of the companies who quoted for the job would have used in the first place!):

Full information on this product here:
http://www.holyoake.com/product-details/ECO-A_item.html?reg=NZ&ref_cat_id=ECO-Diffusers

[The same company make a different type which comes in manual or automatic versions, but it appears to be available in a minimum of 200mm (I have four 150mm and one 200mm vents I need to replace).]

Anyway, after that long rant, can I please ask for some advice and feedback on my best options here? Earlier in this thread there have been some really useful replies from those who clearly know this kind of stuff, and I'd really appreciate your thoughts. In particular -

* What type of vent would I be best to replace the five diffusers with, given I need these primarily for firing air downwards for heating to solve my current stratification problem but ideally also adjustable sideways for cooling?
* Will the vents with the thermostat built in to manage the air direction work satisfactorily in these circumstances?
* Are there other companies supplying aircon vents/diffusers in NZ (other than Holyoake and Smooth Air) that may offer such suitable products?

Thanks so much for any feedback.

gedc

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#1404213 12-Oct-2015 11:16

Hi Jonathan. We PM'd a while back and I suggested to remove the cores to check re the stratification issues - as it worked for me. We eventually changed all the standard diffusers out for the last diffuser as it allows for better cold air distribution during summer i.e fires it out across the room where it then settles quickly. I must add the cooling performance of the ducted systems IMHO is FAR better than their heating performance - I guess even Fujitsu or Daikin can't change the laws of physics.

Did they completely resolve the issues - no but like you got me to a point that was acceptable. I wasn't keen on replastering 12 ceiling holes around the house if we removed the other half of the system as well. Next time I would go for multi split hi walls but hopefully that's a good chunk of time away.

The hollyokes diffusers work a lot better than the standard but still don't compare to having no diffuser and a large hole :)

timtait

133 posts

Master Geek

#1404239 12-Oct-2015 11:57

At the end of the day, would you guys recommend the ducted heatpump option in a new build?

We've been looking at underfloor but it's so expensive, ~25K, where the ducted heatpump is less than 15K.

Also someone mentioned the possibility of floor vents for the ducted systems, have you come across these?

jonathan18

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#1404280 12-Oct-2015 12:50

timtait: At the end of the day, would you guys recommend the ducted heatpump option in a new build?

We've been looking at underfloor but it's so expensive, ~25K, where the ducted heatpump is less than 15K.

Also someone mentioned the possibility of floor vents for the ducted systems, have you come across these?

My answer would be a qualified 'yes'. This would be on the proviso of ensuring I trusted the company doing the design and install (so get recommendations and ask a lot of questions of those you get to do a quote). Also check that the installer has installed the same unit as you're having installed (many of my problems came from the newness of the product, which they'd never installed before). Further, read these kinds of threads to find out the problems others have had, and ensure you're discussed them with your installer prior to the install - hopefully you'll be able to negate such problems through good design and product choices, but in case this doesn't happen if you've agreed on a course of action to sort any problems when they do occur beforehand it should be easier to fix them. Be wary of getting the latest technology, and be sure you fully understand the limitations of the system (eg, our system's inability to set, manage or cancel seven-day timers remotely via the internet is a terribly stupid limitation, eg couldn't cancel timers if away from the home for say a holiday). Ideally, talk to someone who's got a particular model installed about their experiences with it.

I imagine that ducted heatpumps in a new build will cause fewer issues than retro-fitting into an old house. Better insulation so lower heat loss will help straight away, let alone being able to ensure best placement of equipment, vents etc. Generally I've been told that floor vents will work better for heating, and personally my experiences with ducted heatpumps prior to getting ours installed were the houses of my in-laws and friends, both who had it installed via floor vents (one as they were replacing gas central heating, so were able to re-use the same ducting; the other as it was two story so floor vents for the bottom story was the only option). Of course, with a new build a concrete foundation will make floor venting a heatpump somewhat difficult! But, if given the choice, I'd elect for floor ducts as heating will always be more critical to me than cooling (especially in a new build, where good design should minimise the need for cooling in summer).

In your case, that $10k difference is substantial - especially as I assume the running costs of a heatpump will be lower than underfloor heating (depending on your source for this?); I've also read enough on other GZ threads to have concerns that underfloor heating has its design and operating issues too... Personally, I'd go for the ducted heatpump...

jonathan18

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#1404299 12-Oct-2015 13:15

gedc: Hi Jonathan. We PM'd a while back and I suggested to remove the cores to check re the stratification issues - as it worked for me. We eventually changed all the standard diffusers out for the last diffuser as it allows for better cold air distribution during summer i.e fires it out across the room where it then settles quickly. I must add the cooling performance of the ducted systems IMHO is FAR better than their heating performance - I guess even Fujitsu or Daikin can't change the laws of physics.

Did they completely resolve the issues - no but like you got me to a point that was acceptable. I wasn't keen on replastering 12 ceiling holes around the house if we removed the other half of the system as well. Next time I would go for multi split hi walls but hopefully that's a good chunk of time away.

The hollyokes diffusers work a lot better than the standard but still don't compare to having no diffuser and a large hole :)

Hi Ged,

Thanks for your post, and for reminding me about your advice sent via PM - I've replied directly to you via the same method!

Good advice re testing the heatpump without the diffusers, and good to know the Holyoake one is worth checking out; will give the company a call. I can't say I like the look of the silver ducting visible through the big holes in our ceilings, so will take a performance hit to improve the aesthetics! And these will certainly offer an improvement on the current diffusers.

I had forgotten that Securimax also does grills and ducting, but they also don't appear to have any diffuser that offers the air angle switching of the Holyoake unit, whether it be manual or automatic. The closest I found was this one, which claims to push air out sideways as well as down, but I doubt it will be the solution we need.
http://simx.co.nz/ducting/pdf/Securimax_Ducting_Catalogue_Full.pdf#page=61

meesham

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Ultimate Geek

#1404303 12-Oct-2015 13:18

I just wanted to say thank you for following through with your promise and letting us know how the system is after you've had it for a while :) I'm still trying to decide what to do about heating my 1920s bungalow with 3m stud so your experiences are very helpful.

zyo

513 posts

Ultimate Geek

#1459065 30-Dec-2015 15:37

We have had a ducted Panasonic S60 installed by heatpumpsauckland.co.nz about a year go.

The unit was very quiet but we were not offered any option to divide the rooms into different zones.

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Dingbatt

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#1459205 30-Dec-2015 18:17

As I sit sweltering in the Auckland humidity, my thoughts have turned, once again, to the idea of airconditioning the house. And heating in the winter of course. We have a cassette style Panasonic unit that does the job in our open plan living area but struggles to cool/heat the adjacent lounge. And won't manage the bedroom end of the house. I hate the look of hi wall and floor standing units, which is why we went for the cassette in the first place as it doesn't encroach into the room. So I was seriously considering a ducted system but have been somewhat put off by the experiences outlined in this thread.

@zyo How did you find heatpumpsauckland to deal with?

I would also like to incorporate a level of automation, so anybody's additional comment to that already stated earlier would be appreciated.

I have even considered losing some wardrobe space and putting in bulkhead units just so they are hidden.

“We’ve arranged a society based on science and technology, in which nobody understands anything about science technology. Carl Sagan 1996

zyo

513 posts

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#1459280 30-Dec-2015 21:16

Dingbatt: As I sit sweltering in the Auckland humidity, my thoughts have turned, once again, to the idea of airconditioning the house. And heating in the winter of course. We have a cassette style Panasonic unit that does the job in our open plan living area but struggles to cool/heat the adjacent lounge. And won't manage the bedroom end of the house. I hate the look of hi wall and floor standing units, which is why we went for the cassette in the first place as it doesn't encroach into the room. So I was seriously considering a ducted system but have been somewhat put off by the experiences outlined in this thread.

@zyo How did you find heatpumpsauckland to deal with?

I would also like to incorporate a level of automation, so anybody's additional comment to that already stated earlier would be appreciated.

I have even considered losing some wardrobe space and putting in bulkhead units just so they are hidden.

They are pretty good overall, the price is very competitive we had a ducted system and a standard split system installed at the same time. They are very busy during summer so we had to wait almost til the end of the summer to get the units installed :(

During the installation one of the guys damaged our ceiling and they issued us a refund for the repair.

Dingbatt

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#1747545 25-Mar-2017 12:52

Revisiting this thread again as we are now in a position to be able to afford a ducted system and would like an update from anyone who has had a ducted system installed since the thread was last active.
We are looking at a 14kW system from Fujitsu and Panasonic.
Our home is fairly well divided between living and bedroom areas. Is there any value in dividing it into two zones so you are only hearing/cooling the end of the house being used? The downside is, this particular system doesn't allow app control of multiple zones. And how did the different diffusers work out @jonathan18 ?
I am in Auckland and have had consultations with Varcoes, OxygenAir and heatpumpsauckland. Does anybody have any comment on any of these companies?

“We’ve arranged a society based on science and technology, in which nobody understands anything about science technology. Carl Sagan 1996

jnimmo

1097 posts

Uber Geek

#1747580 25-Mar-2017 14:16

Dingbatt: Revisiting this thread again as we are now in a position to be able to afford a ducted system and would like an update from anyone who has had a ducted system installed since the thread was last active.
We are looking at a 14kW system from Fujitsu and Panasonic.
Our home is fairly well divided between living and bedroom areas. Is there any value in dividing it into two zones so you are only hearing/cooling the end of the house being used? The downside is, this particular system doesn't allow app control of multiple zones. And how did the different diffusers work out @jonathan18 ?
I am in Auckland and have had consultations with Varcoes, OxygenAir and heatpumpsauckland. Does anybody have any comment on any of these companies?

We've got a small 3 br house in Christchurch with about a 10kw Fujisu ducted system in a new build. Very happy with it; although it is a lot of money and will be interesting to know the lifespan of it.

Hard to know whether would be worth creating zones in Auckland - we've got two spare rooms which share supply from one duct, so have put a damper on that

Can always use something like this https://www.itead.cc/motor-reversing-wifi-wireless-switch.html to create your own zone control too

timtait

133 posts

Master Geek

#1747751 25-Mar-2017 23:08

We moved into our new place in September and couldn't be happier with ours.

16kw Panasonic unit heating roughly 180m2 of living space at a cost of just under $12K installed.

I looked into zoning it so we could turn the living area on and the bedrooms off but in the end we went with a single zone. I'm glad we did because now we have the whole house nice and warm / dry and the system is so cheap to run. We're on ElectricKiwi at 23C/K, we had the heating running most nights after we moved in until after christmas, our biggest power bill was ~$150 (we do have gas hotwater though).

Here's the October break down where we had it running most nights, we're working out under $5 a day most days.

But in saying all this, we're in a brand new house where the walls / ceilings are insulated about as high as you can go + double glazing etc all around. The heating doesn't force air our like a typical heatpump, it just sort of falls out so I can imagine unless you have the top notch insulation it wouldn't work as well / would cost a lot more to run.

mattwnz

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#1747823 26-Mar-2017 01:26

Dingbatt: Revisiting this thread again as we are now in a position to be able to afford a ducted system and would like an update from anyone who has had a ducted system installed since the thread was last active.
We are looking at a 14kW system from Fujitsu and Panasonic.
Our home is fairly well divided between living and bedroom areas. Is there any value in dividing it into two zones so you are only hearing/cooling the end of the house being used? The downside is, this particular system doesn't allow app control of multiple zones. And how did the different diffusers work out @jonathan18 ?
I am in Auckland and have had consultations with Varcoes, OxygenAir and heatpumpsauckland. Does anybody have any comment on any of these companies?

Have you looked at getting a multi unit system instead of ducted? I am looking into one of these myself, possibly a mitsubishi one, and they seem to give more control than a ducted one. The ducted one wasn't any option as I don't have enough rood space for the large ducts. Getting info from the companies though is difficult, and some don't bother to reply.

jonathan18

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#1747904 26-Mar-2017 10:20

Dingbatt: Revisiting this thread again as we are now in a position to be able to afford a ducted system and would like an update from anyone who has had a ducted system installed since the thread was last active.
We are looking at a 14kW system from Fujitsu and Panasonic.
Our home is fairly well divided between living and bedroom areas. Is there any value in dividing it into two zones so you are only hearing/cooling the end of the house being used? The downside is, this particular system doesn't allow app control of multiple zones. And how did the different diffusers work out @jonathan18 ?
I am in Auckland and have had consultations with Varcoes, OxygenAir and heatpumpsauckland. Does anybody have any comment on any of these companies?

@Dingbatt - we never ended up replacing the diffusers - my wife's cousin, who's an installer in Akld, was going to do it on the cheap for us, but that didn't end up happening. Thus far we've coped with the fairly ugly holes with no diffusers in them, but certainly when we get the money together will replace them - most likely with the sensing versions I discussed above.

I recall the Panasonic units didn't come with built-in support for zones, whereas the Daikin units do. Have you looked at Daikin? Obviously not the model I selected (but that's no longer available - confirmation it was cr@p), but there are other options which are well-regarded.

Zones do bring in the problem of ensuring well-placed sensors in each zone, as I documented above! I'm not sure it was totally critical to get zones, and certainly when we are all up and about we just warm the whole house. We did it more so we could run the system at night so warm the bedrooms but not the rest of the house, but in reality last winter we didn't bother with this and instead just started it at about 5.30 to warm the whole house. In practice it's been really cheap to run - I'm positive we're paying less in total for our electricity for heating versus what we previously spent on wood, gas and electricity.

You can also elect to shut the diffusers in particular rooms if they're not being used and shut off.

I still believe the decision to go with a ducted system was the correct one (for us) compared to installing multiple split units - personally, I'm not keen on having multiple outdoor units around the outside of the house, nor am I fan of the way the indoor units of a standard install are quite dominant aesthetically. I also find the more diffused air coming from the ducted system less annoying than the often significant airflow from a conventional unit. But, as posts above indicate, others have very different ideas!

Dingbatt

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#1747962 26-Mar-2017 11:32

@jonathan18 Thanks for your reply. I am leaning towards a single zone initially as it would appear zoning can be retrofitted if deemed appropriate (but will confirm with engineer prior to going ahead). That would mean retuning the system but the extra cost later may be better than specifying initially, and then not needing. Effectively, it is probably better to condition the whole house and then maintain, rather than yoyo back and forth between the two zones. With our current cassette type heatpump we were only using the cooling side of things for about 6 weeks in the peak of summer but, due to a new subdivision in our area, road in front of our house has got a whole lot busier, so I can see the windows being left closed and the air-conditioner being used a lot more in the future.

@Mattwnz I have previously investigated a multi-head arrangement but decided against it for two reasons. Firstly cost, approximately 30% dearer than ducted for our application, and secondly, I prefer stuff to be hidden, so don't like highwall units especially in every room. However, in your circumstance if there isn't enough roofspace, then that limits your options. What the multi head does gain you though is granular control of the conditions in each room and no problems with return airflow.

“We’ve arranged a society based on science and technology, in which nobody understands anything about science technology. Carl Sagan 1996

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