Heat Pump Thoughts

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Mad Scientist
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#1342530 13-Jul-2015 20:04

lissie:
Hammerer: Lowest recorded temperature up on the hill at Kelburn is only -0.1C. Although there has been snow falling at sea level it doesn't last long.

I'm in Lower Hutt where we get a lot more frosts. We have our external unit sitting in the morning sun which helps a lot on frosty days. But we've never had any problem running it in the night or without sun. It takes 10 minutes at most to heat our dining room and kitchen.

Sounds like Tawa too - I'm by the west coast of Titahi Bay - definitely warmer than the Hutt, Tawa, or Whitby. The outdoor unit is on the east side but gets no sun in the winter - so that's probably not helping. Someone just said on FB that they are suposed to actually blow proprely hot air (her's was measured at 45C) - if that's the case this one has a problem - it's never been better than warm air out

Previous house had a 12 yo daikin and brand new Fujitsu.
Daikin blew seriously hot air. Fujitsu blew warmish air. Till today i have no idea why. The engineers tell me 6kw is 6kw no matter how hot the air ....

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#1344849 15-Jul-2015 16:15

lissie: HP create a nasty heats in my view- I don't like having hot air blown at me. We are considering getting rid of ours and either replacing it with an unflued gas heater. When we get bored with chopping wood I've heard good things about pellet burners

Don't think about an unflued gas heater. You will be very disappointed. I think the figures are something like one litre of water released to the atmosphere for every litre of gas burnt.

Unflued gas heaters make your house damp and therefore harder to keep warm. There was one on our house when we bought it. We used it for the first winter, never again. A single 2.4kw column heater does a better job than the 3.6kw unflued gas heater.

A properly sized and correctly installed heat pump gives the best bang for your heating buck IMHO.

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#1344858 15-Jul-2015 16:27

Technofreak:
lissie: HP create a nasty heats in my view- I don't like having hot air blown at me. We are considering getting rid of ours and either replacing it with an unflued gas heater. When we get bored with chopping wood I've heard good things about pellet burners

Don't think about an unflued gas heater. You will be very disappointed. I think the figures are something like one litre of water released to the atmosphere for every litre of gas burnt.

Unflued gas heaters make your house damp and therefore harder to keep warm. There was one on our house when we bought it. We used it for the first winter, never again. A single 2.4kw column heater does a better job than the 3.6kw unflued gas heater.

A properly sized and correctly installed heat pump gives the best bang for your heating buck IMHO.

Absolutely agree, my in laws for some reason got one of those terrible things, they also have a heat pump. They did not understand that heat pumps are not good for direct heat and need time to get your room to a comfortable heat.
Long story short, the windows streamed water and the heat pump was working overtime to try and cope. I finally convinced them to dump the unflued gas heater and their home is now warmer and dryer.

lissie

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#1344896 15-Jul-2015 16:59

Technofreak:
lissie: HP create a nasty heats in my view- I don't like having hot air blown at me. We are considering getting rid of ours and either replacing it with an unflued gas heater. When we get bored with chopping wood I've heard good things about pellet burners

Don't think about an unflued gas heater. You will be very disappointed. I think the figures are something like one litre of water released to the atmosphere for every litre of gas burnt.

Unflued gas heaters make your house damp and therefore harder to keep warm. There was one on our house when we bought it. We used it for the first winter, never again. A single 2.4kw column heater does a better job than the 3.6kw unflued gas heater.

A properly sized and correctly installed heat pump gives the best bang for your heating buck IMHO.

We had a renovated 1940s weatherboard (no wall insulation - single glazed) - we had an unflued wall gas heater in the corridor (no longer available) and the smallest unflued gas heater (not LPG -bayonet on CNG). The area was large open plan - I never got around to curtains - the little heater warmed it quickly - never had a condensation problem.

I am trying another company re getting the HP serviced- and we have ceiling insulation and double-glazing in progress which may make the job easier for it

That said I don't want to run a heater 24/7 as some suggest in this thread - if you have to run a HP 4 x longer than a regular heater to warm a room - there is no savings in power to be had.

The more I look into it there seems something very odd in the HP/heating industry. Some people with 2 HPs running 24/7 report power bills for under $200 - others have reported huge power bills. There is something odd going on.

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timmmay

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#1344914 15-Jul-2015 17:16

lissie: I am trying another company re getting the HP serviced- and we have ceiling insulation and double-glazing in progress which may make the job easier for it

That said I don't want to run a heater 24/7 as some suggest in this thread - if you have to run a HP 4 x longer than a regular heater to warm a room - there is no savings in power to be had.

The more I look into it there seems something very odd in the HP/heating industry. Some people with 2 HPs running 24/7 report power bills for under $200 - others have reported huge power bills. There is something odd going on.

You don't want a regular service, cleaning filters and such, you need a trained and qualified technician to look at it properly.

I run my heat pump as required, same as you would a regular heater. It heats faster and uses less power. You can't make generalizations based on your old or faulty unit.

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#1344920 15-Jul-2015 17:31

i think its a combination of poorly/incorrectly specd unit combined with the shape of a space its trying to heat thats the issue in her case

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#1344935 15-Jul-2015 17:57

lissie: We had a renovated 1940s weatherboard (no wall insulation - single glazed) - we had an unflued wall gas heater in the corridor (no longer available) and the smallest unflued gas heater (not LPG -bayonet on CNG). The area was large open plan - I never got around to curtains - the little heater warmed it quickly - never had a condensation problem.

Unless they've been renovated older houses tend to be drafty, as a result the air is moving and changing which will result in less or no condensation and of course the house is harder to heat

lissie: That said I don't want to run a heater 24/7 as some suggest in this thread - if you have to run a HP 4 x longer than a regular heater to warm a room - there is no savings in power to be had.

The more I look into it there seems something very odd in the HP/heating industry. Some people with 2 HPs running 24/7 report power bills for under $200 - others have reported huge power bills. There is something odd going on.

If you're running a heat pump 4 times longer than a regular heater then something isn't right.

One of the problems with a heat pump is if it's working hard it's not efficient. A poorly insulated house and or a heat pump that's too small for the job will significantly impact how well it works.

A heat pump can ice up especially if it's working hard. Once it ices up it stops providing heat and needs to defrost itself. If it's struggling to heat the room and needs to regularly defrost, the room never really gets warm. The power bill is high from all the constant cycling of full on heating then defrosting. A correctly sized pump will avoid these issues and use less power.

Another area where people create problems and potentially over work even a correctly sized heat pump is setting a high temperature when they turn the heat pump on with the idea of warming the room quickly. Setting a higher than necessary temperature won't warm the room any quicker.

The heat pump will work at it's max capacity until the desired temperature is reached. An ideal temperature is generally around 22 to 24 C. By setting too high a temperature means the heat pump is working harder for longer to get to that temperature and increases the chances the unit will ice up.

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cldlr76

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#1344943 15-Jul-2015 18:17

Thanks for all the replies, I think it might be back to the research and include a ducted system. We aren't in a real hurry and want to make sure we do it right.

Is there a better time of year from a deals point of view to buy?

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#1344981 15-Jul-2015 19:58

cldlr76: Thanks for all the replies, I think it might be back to the research and include a ducted system. We aren't in a real hurry and want to make sure we do it right.

Is there a better time of year from a deals point of view to buy?

I don't know about the best time of year to buy, as we've decided to get it done ASAP - we're over having half our house too cold. (But I shouldn't be complaining - my sister, whose house was irreparably damaged by the Chch quake and still hasn't had it replaced said she gets ice on the inside of the windows, and one of her rooms was -1 the other day!)

If it helps, given I've been getting quotes for a heatpump installation over the past couple of weeks (in our case for a ducted system), the points I'd note from the experience are:

* you'll get really different advice from different companies, for example this has led to my questions on the other recent thread asking for an independent view on the best selection of vents (I still don't know the answer!)

* similarly, different companies will push certain brands and dismiss others; while this may sometimes be based on actual experience (there really was a groundswell against the quality of Fujitsu products - which reflects badly on that fact we have two Fujitsus already!), I think it often comes down to the brands they have a good relationship with (and therefore can get good discounts on)

* following on from that previous point, clearly a close relationship with a company can mean getting units as a good price, so they can be more competitive with that brand. For example, we have decided on a particular Daikin unit, due to having zone control built in. The company that was way cheaper to install the same sized Panasonic said he didn't have a chance of matching the price from the other company to supply/fit that specific Daikin model (and said it wasn't even worth quoting for it)

* so it really does pay to get multiple quotes, and I suggest if you're particularly keen on a certain model then get quotes for that exact model from multiple companies; in my case, once I'd decided on a particular model I checked out the other 'official' Daikin dealers on their website, assuming they'd have a similar relationship so similar buying power. (As it happens, this second quote for the same unit came in $1200 more expensive than the initial quote

* if you do go down the route of a ducted system, ensure they fully explain how the system works (plus there's some really useful comments on the other thread from other members, such as issues that may result from having doors shut), including what level of control you'd have over the system, its upgradability (so even if you may not want zones now, would it be best to select a model to which its easier to add them later?) etc.

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#1345011 15-Jul-2015 21:07

jonathan18:
* similarly, different companies will push certain brands and dismiss others; while this may sometimes be based on actual experience (there really was a groundswell against the quality of Fujitsu products - which reflects badly on that fact we have two Fujitsus already!), I think it often comes down to the brands they have a good relationship with (and therefore can get good discounts on)

It is not a representative sample that you could draw any reliable conclusions from. I won't be the only person who read the thread but didn't say what units we use.

Ours were relatively cheap to install, correctly sized so they work efficiently and effectively, have worked without problems for years, and are very quiet - the main noise seems to be from the moving air rather than the fans. For the record, they are both Fujitsu. I know other people with models from the same range that function well just like ours.

I do agree about the discounts being important. If you need more than one unit then it is worth getting both done at the same time. Our installation cost per unit dropped significantly.

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#1345019 15-Jul-2015 21:31

jonathan18: (there really was a groundswell against the quality of Fujitsu products - which reflects badly on that fact we have two Fujitsus already!)

Fujitsu are good units
I am sorry but after working in the industry for 7 years and selling thousands of units you would struggle to convince me otherwise.
The company I work for sells other brands as well as fujitsu so I am not that brand bias it's just simple they are not bad units.

They are often put down by others in the industry because they are the biggest sellers (residential) in NZ to give you an example the last BDT presentation (mitsubishi electric importers) presentation I went to they spent half the time attempting to put down fujitsu's product while presenting very little factual information.

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#1345026 15-Jul-2015 21:46

lissie: The more I look into it there seems something very odd in the HP/heating industry. Some people with 2 HPs running 24/7 report power bills for under $200 - others have reported huge power bills. There is something odd going on.

I assume you know how to use a heatpump?

i.e. you set it to the desired temperature e.g. 22 degrees. then wait for it heat to the desired temp which will take 10-30-60 minutes depending on the area you're trying to heat.

If you're setting it to 30 degrees to try and get it "hot" like a gas or wood burner does then that is your issue.

Also set the heatpump to turn on around 4 or 4:30pm i.e. BEFORE you get home. The outside air is warmer therefore it's easier to "extract" the heat from the air.
As the night gets colder the heatpump has to work harder to "extract" heat from the outside air.

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#1345044 15-Jul-2015 22:31

mentalinc:
lissie: The more I look into it there seems something very odd in the HP/heating industry. Some people with 2 HPs running 24/7 report power bills for under $200 - others have reported huge power bills. There is something odd going on.

I assume you know how to use a heatpump?

i.e. you set it to the desired temperature e.g. 22 degrees. then wait for it heat to the desired temp which will take 10-30-60 minutes depending on the area you're trying to heat.

If you're setting it to 30 degrees to try and get it "hot" like a gas or wood burner does then that is your issue.

Also set the heatpump to turn on around 4 or 4:30pm i.e. BEFORE you get home. The outside air is warmer therefore it's easier to "extract" the heat from the air.
As the night gets colder the heatpump has to work harder to "extract" heat from the outside air.

Hmm yes - set on "heat" "high" and "23C . If we're going to be home at night we use the log burner - way faster. The main benefit of the thing would be in he mornings - but it really doesn't work when it's dark ie it's too cold!

But whatever I set it at - it never blows more than slightly warm air - nothing like hte 50C that apparently it's supposed to do so -hence one more attempt at a service.

On the plus side - it IS a very good air con - we used it twice over the summer!

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#1345108 16-Jul-2015 06:45

Have you tried using it with fan set to auto and the "vane" (both vertical and horizontal) also set to auto?

I found mine work s better when it's all on auto.

But it sounds like your concern is around the type of heat. You like the uncontrolled heat that log burners put out compared to a warm room which a heatpump provides

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#1345124 16-Jul-2015 08:20

mentalinc: Have you tried using it with fan set to auto and the "vane" (both vertical and horizontal) also set to auto? I found mine work s better when it's all on auto. But it sounds like your concern is around the type of heat. You like the uncontrolled heat that log burners put out compared to a warm room which a heatpump provides

I want to be warm, I don't really care if my sofa is warm too :-) Yes I've tried all the variations of the buttons

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