Help me choose a heat pump

[Scaredy Cat]

Hi,

We are currently renovating our lounge/kitchen at the moment and we are looking at getting a heat pump.

This is where I need some help, could those of you who have a heat pump/know about heat pumps give me your opinions of the ones you own/have worked with. This would include the pain of installation, price, reliability, noise both inside and outside, warranty problems, temperatures they work till etc.

The problem I have is that everytime I see a professional about it they claim that their one is the best. After some searching I found that Fujitsu have recently brought out a new version that works down to -15 degrees which is good for Dunedin winters

Anyway any help would be greatly appreciated. Thanks.

[Hitcher]

The most important thing to note about heat pumps is their location in the room. They blow air around and create a draft. If you don't like sitting down or sleeping in a breeze, then you could be in for some problems.

Otherwise heat pumps are magnificent and I am unsure why they haven't caught on more in New Zealand. Any form of heating/cooling that is 150-500% efficient has got to be good value.

[Deano]

Hi,

noise both inside and outside, .

Ive never measured internal noise but it would need to be insulated from the dwelling to prevent structure borne sound.

Be careful where you site it - Ive monitored three different brands of heat pump (Fujitsu included) that were located within 2 metres of the property boundary, and they did not comply with District Plan or NZ Standard recommended noise levels. (You can check your city's District Plan at the Council)

The noise output specified on the pump ranged between 40 and 60dBA from memory.

Depending on the background noise levels, you may be required to achieve as low as 35dBA at the boundary, possibly even lower.

Locate the pump as far away from your neighbours as possible. The ones I have monitored have all had to carry out some form of shielding, or relocate the pump.

[sels1]

Hi,
The problem I have is that everytime I see a professional about it they claim that their one is the best. .

Like many things these days they all come out of the same factory ( well 3 or 4 factories) with just cosmetic differences. Any of the major brands will do the job. There are some brands coming out of China that are cheaper...but you get what you pay for. (although some of the main brands are manufactured there now.)

After some searching I found that Fujitsu have recently brought out a new version that works down to -15 degrees which is good for Dunedin winters.

Good feature - heat pumps were originally just adapted (with reversing valve fitted) air conditioners that were designed for warm climates and they struggled to produce much heat when the ambient temp dropped below around 5deg( some even had electic booster heaters) however modern units have overcome this to a large extent with improved coil and compressor design.
Fujitsu are a good recognised brand and if they are rating that model in that temp range then it could be your best option, considering Dn's climate. I recommend buying from a refrigeration/air cond company that can service what they sell, as opposed to appliance stores or power companies that just contract their installations out (sometimes to cowboys!)

[Scaredy Cat]

Thanks for all your help so far.

I contacted the DCC regarding noise and they said it would have to be 30 dBA or less at the boundary line to take into account the heat pump going at night. Now the heat pump pamphlet reckons that the noise level at the outside unit is 47 dBA at 1 m away. Luckily the heat pump would be right in the middle of both our neighbours about 4 - 5 m away from both boundary lines and would be facing the road which is very wide so the neighbours way across the street wouldn't be able to hear it (it doesn't matter anyway cause those neighbours have a lawnmowing fettish, they mow the lawns every 2 - 3 days and drives us nuts). The DCC said they could check the noise levels for us once the pump is in but if its not up to standard they could tell us to shield it or remove it which would be a waste of money putting it in the first place.

The internal noise is rated at 43 dBA at 1 m which is alot louder than mitsubishi which say 21 dBA for their units. But with the TV/stereo going hopefully it will drown the sound out.

Regarding a breeze in the room with the heat pump going, it doesn't really bother me as longs as its warm air. We are hopefully planning on going with a air conditioning company, my uncle is a plumber and has some friends so I will chat to him about it. I don't really want to buy it from applicance shops, we went into one and the salesperson said "what's a heat pump"?

[Spin]

Hey Scaredy Cat

We used to live in Dunners and had three separate heatpumps - two of them were actually inverters (more efficient)

The first one we had was a Fujitsu - worked fine but had more down time that the Daikens that we had subsequently - the two Daikens we had were great - and the installers were the best

We had the big ones - cost about $4500 - 7.7kw I think - you need the big ones for Dunners -..

Noise of things were no problem - either outside or inside - the old ones used to be noisy

We had the floor mounted ones - seemed to make the most sense to us - heat rising and all - but if you have kids they could be a problem with little fingers breaking bits off etc

Where you install it is crucial - as is the layout of the house - trust in your comon sense

Good luck - we think they are the only way to heat a house - clean, healthy, cheap to run, and amazingly convenient

[Deano]

I contacted the DCC regarding noise and they said it would have to be 30 dBA or less at the boundary line to take into account the heat pump going at night. Now the heat pump pamphlet reckons that the noise level at the outside unit is 47 dBA at 1 m away. Luckily the heat pump would be right in the middle of both our neighbours about 4 - 5 m away from both boundary lines

47dBA @ 1m will equate approximately to 37dBA at 4m and 32dBA @ 8m, so be wary about meeting the 30dBA limit.

Insist from the pump installer/seller, that the operation of the pump will meet all relevant rules and regulations, particularly noise. Then if someone complains and remedial work is required, you can put the onus back on the pump company. This happened with a job I was working on and the company paid to have a shield installed - basically a 12mm plywood tunnel (to allow airflow) lined with carpet underlay.

In another example, a different company were reluctant to use a similar tunnel as they said it would decrease the efficiency of the pump, and so they lined the boundary fence with Hardies board instead. This closed up all the gaps in the fence but I don't think it has yet acheived a "reasonable" noise level. This job still ongoing.

[pete376403]

Heat pumps are something I've been thinking about as well. Anyone have any opinions on the units offered by this outfit?
http://www.trade-me.co.nz/House-gard...n-21937405.htm

[geoffm]

I can't help you with installers in the Deep South (there are a few in Auckland I wouldn't touch...) but get a proper air conditioning co to install it, otherwise the compressor warrenty is void. You should purge the lines with nitrogen before brazing to stop lumpy bits being sucked into the compressor from the oxidised copper pipe.
There are limitations on line size, length and vertical rise of the connecting pipes between the indoor and out door units. RTFM. You will also need provision for a condensate drain from the indoor unit, so consider where this is going to run.
Get the company to do a heat load calc on the house to make sure you get the right size for your house. If they won't do it/ give you a blank look, go elsewhere.
Geoff

[Kickaha]

I have a Panasonic CS-G123KE 3.45kw cooling/4.80kw heating ,when I first got it I found the noise fron the inside unit intrusive but after a few days I didn't even notice it any more,air flow direction can be directed by the unit using the remote control

As for the outside unit I suppose it makes some but I haven't ever heard it

In winter in Rangiora the ouside unit wll shut down to defrost if it gets to cold and this sometimes takes 10-15 minutes and the room temperature will drop noticably in that time,I've been told the Daikin are better in that respect

It makes a difference of about $30 a month to the power bill through winter with it being used for about 5 hours a day,the only thing I dont like about it is that you can only set it to turn on and off once per day instead of turning on before you get up and off when you leave for work and coming on before you get home again

[gav]

We installed a Mitsubishi MSH-18RV and have found it to be bloody marvelous. Real good in summer as a cooling aid too.
Best thing is maybe ask for a free quote, and they can measure size of room and recommend what size unit is suitable for your living area. Once you know what you need you can then shop around for what is going to do the job.

[Scaredy Cat]

47dBA @ 1m will equate approximately to 37dBA at 4m and 32dBA @ 8m, so be wary about meeting the 30dBA limit.

Insist from the pump installer/seller, that the operation of the pump will meet all relevant rules and regulations, particularly noise. Then if someone complains and remedial work is required, you can put the onus back on the pump company. This happened with a job I was working on and the company paid to have a shield installed - basically a 12mm plywood tunnel (to allow airflow) lined with carpet underlay.

In another example, a different company were reluctant to use a similar tunnel as they said it would decrease the efficiency of the pump, and so they lined the boundary fence with Hardies board instead. This closed up all the gaps in the fence but I don't think it has yet acheived a "reasonable" noise level. This job still ongoing.

Thanks for that, more to think about I guess. Here is another question, if the fan etc of the heat pump are not pointing at either boundary but parallel to them would that make a difference in terms of noise?

[Deano]

Thanks for that, more to think about I guess. Here is another question, if the fan etc of the heat pump are not pointing at either boundary but parallel to them would that make a difference in terms of noise?

I vaguely recall checking that out and from memory it was a very small difference - perhaps 1 or 2 dBA but I can't be sure sorry.

[Skunk]

I was told to bypass heat pumps and go for a HRV system. Anyone got comments (the Poms maybe... I was told they are popular over there )

[pete376403]

I was considering putting the outside unit up on the roof (odd shape house, where I want the interior unit is close to the centre of the house). The guy advertising the units on trade-me (earlier post) said this is do-able. Would also get the fan further from the boundary.