Heat Pumps - post here.

I was missing details.
I have the stats set to drop back by ~2C from about 11pm so there is little or no demand on the heat pump.
Rest of house takes very little input from UFH to maintain a constant temperature throughout the day/night.
All other areas of the house maintain their temperature pretty well, so it is only the sunroom which drops off.
The room is ~ 5m x 4m with a 2m x 1.5m window on each side and a large arched window on outside gable which has ~12m2 of glazing.
In an ideal scenario, I would have reduced the sunroom glazing by at least a factor of 2 which would be more conducive to maintaining a constant temperature, but I wanted a bright & light filled room.
Just wondering if others have similar experiences.

Big Dec wrote: »

I have a question regarding solar gain & heating which I have noticed recently in relation to my own house.
I'm only in the house since end of October & still tweaking the GSHP settings.
With our typical Irish weather we can have sun for a portion of the day & then it can be quite cold once the sun has gone down.
A few times, I have come home to a warm house due to solar gain, but when the temperature drops it takes the UFH quite a while to bring it back up to temperature as the UFH in that area (and most of the house in fact) has been off since the previous night.
Anyone have any experience with this?
We like to have the sunroom a bit warmer as this is our main living room, just off the kitchen.
Could I set the stat to be a high temp (to ensure zone is opened) earlier in the day to charge up the floor in that area, before dropping it back to the desired temperature a while later.
The sunroom has a vaulted ceiling with a log of glass, so does heat up quickly with the sun & also loses the heat a little faster than the rest of the house.

Firstly I would be checking the balance of the system it's possible the flow is being directed elsewhere and the sunroom isn't getting enough when required. Also check the location on the thermostat...that's it's not in sunlight as this will hold the zone off for longer,

I'd also not have any setback at night. If your on night rate then you should really not have setback as you want to get the best out of the low tarrif by charging the slab of concrete up more during the night, the extra heat can then dissipate during the day. Bedrooms may be the exception as you don't want the room too warm while sleeping.

Also are you at a fixed set point for supply water, you may consider running on a heat curve if your HP supports this.

Big Dec wrote: »

Sorry, have not been online for a bit.
Thanks for feedback.
As with all posts here, it looks like every house behaves differently & you just have to tweak the system as per your requirements.

@Calahonda52
When I mentioned about the UFH being off since previous night, I meant that there was no demand from any of the zones.

@g1983d
The system already has weather compensation built in.
My issue is that OH likes the sunroom "toasty" in the evening, but that means that the kitchen gets quite warm too as there is a big opening between the two rooms. Kitchen has tiles & sunroom has laminate so there is a faster heating response from kitchen.
I don't want the kitchen to be too warm during the day.

@ShanE90
There is plenty of flow directed to the sunroom as no other zones are generally calling for heat.
Due to all the glazing in the sunroom, it heats up pretty quickly during the day, but I think there is then a lag between when the sun goes down & the UFH kicks in & gets the room to temperature.
Unfortunately I am at a fixed set point for the supply water. I was playing around with the installer SW yesterday & there does seem to be an option to control the flow temp. Is that what you were referring to? I could then increase that for a certain period of the day & reduce back to nominal value.
I might also play a bit with charging the slab up a bit more during the night & not reducing temp at all in there.

As you describe the setup you have quite a bit of solar gain during the day and when the sun goes in the room cools down. Then by the time the thermostat has called for the zone to open its unable to heat the area in time due to it being UFH which is slow reacting. Can you increase the set point of the room at night so it has more heat to give off during the day, I would do this first turn it up fairly high until you get the temp you want then turn it back degree at a time until you know where is good.

Unfortunately due to the slow reaction of UFH and the quick rise in temps with solar gain you may find it difficult to get right, if you were in a position to put in a fan assisted radiator like a smart rad which could deal with the changing heat load much faster than UFH can it may suit the sunroom better.

sheff the ref wrote: »

How are people managing their heat for times of the year where heat requirement is intermittent.

For instance in April/May and August/September, there may be periods where no heat is required due to warm temperatures and then you might have cold evenings, and then maybe warm temperatures again. Essentially the heating is turned off and a shot of heat may be needed the odd evening. With oil and rads this is possible, but what options are there for a heatpump and underfloor? Are people using other sources of heat for such 'out of heat season' cold evenings?

Hey
We have a stove.5kw version. Heats up the living area. I tried hardwood logs but since converted to compressed saw dust logs. Better performance once the stove is hot we can burn one of these logs every two hours. .if we do more the house gets too hot ..
I leave the heat pump on and set cut off temperature to 18 degrees once it hits that outside the pump will not kick in

Hi all,

We're in the process of getting quotes for an Air to water heat pump for a new build.

What is the best way to compare and contrast the various makes and models? We want to make sure we have a modern unit, low noise which has the best efficiency possible.

If anyone could PM me the details of a reliable provider/installer of renewable technologies also, it'd be appreciated.

Thanks

interested in info also . please pm info

Nibe 320 Water LUX mode question. I have enabled 3 hours temporary lux mode and APP on the phone displayed Immersion in use (Additional heating BT63), same time pump was showing Additional: blocked. So now I'm not sure is its being used or not, I don't have smart ESB meter, so I could not confirm power consumption at the time, the Immersion is 7Kwt.

Can temp LUX use Immersion even its block in other settings?

I have a Daikin air to water split heat pump installed for <5 yrs. I now have a fault with PC board. With the benefit of hindsight, I would not purchase a heat pump. They are too many parts which can and will fail. These parts are very expensive, repairs are controlled by 1 agent (no competition). Also, we are now without heating for 3 weeks which is ok as it's Summer but could as easily been winter.

I have raised my concerns directly with Daikin and they have not bother responding. Please keep in mind there is multiple potential parts that can/ will go wrong and therefore making the unit very expensive. I hope this helps inform those considering heating options.

ct98 wrote: »

I have a Daikin air to water split heat pump installed for <5 yrs. I now have a fault with PC board. With the benefit of hindsight, I would not purchase a heat pump. They are too many parts which can and will fail. These parts are very expensive, repairs are controlled by 1 agent (no competition). Also, we are now without heating for 3 weeks which is ok as it's Summer but could as easily been winter.

I have raised my concerns directly with Daikin and they have not bother responding. Please keep in mind there is multiple potential parts that can/ will go wrong and therefore making the unit very expensive. I hope this helps inform those considering heating options.

Thanks for the feedback. What is your backup for hot water?

Thanks to all who have posted here, great source of information.

I am currently researching for a new build (220msq)and hopefully starting soon. I just received my parliamentary DEAP report and it states that i have a heating requirement of 4932 kwhr/yr and hot water requirement of 3560 kwhr/yr and a heat loss of 230kwper msq. I take it that if i divide 2932 by 220, il get kw per meter sq (22.418).
I just spoke with a rep and he suggest i use a 6kw Daikin Altherma integrated clinder (260 liter tank) with low temp rads (no more than 136 sections) estimating 10 k for installation including rads and pipework, with a cost of 3 to €400 a year.

does this sound right??????????

ct98 wrote: »

I have a Daikin air to water split heat pump installed for <5 yrs. I now have a fault with PC board. With the benefit of hindsight, I would not purchase a heat pump. They are too many parts which can and will fail. These parts are very expensive, repairs are controlled by 1 agent (no competition). Also, we are now without heating for 3 weeks which is ok as it's Summer but could as easily been winter.

I have raised my concerns directly with Daikin and they have not bother responding. Please keep in mind there is multiple potential parts that can/ will go wrong and therefore making the unit very expensive. I hope this helps inform those considering heating options.

Sorry for picking you out CT98,
my rep seems quite approachable and has directed me in different directions in relation to other aspects. Have you approached where you purchased the product or gone directly to Daikin. What other issues have you encountered????
what system would you go for if not HP?

There are problems with Heatpumps, believe me I was without heating/hot water for almost 4 weeks due to brakdown of outdoor unit of a Daikin split system. Initially I was told it was the PCB board, but later told it was PCB Board, Compressor and Fan motor. These parts are not repairable and are very expensive to replace.

My unit was less than 5 years in running (only 3 yr warranty on my unit) and I contacted Daikin directly and I found them extremely unhelpful and even rude questioning the truth of what I was saying.

The unit is now running and I have since spoke with heat pump engineers (not Daikin) and they cannot understand how all 3 could fail at same time and since I should have looked for proof of failure. However the Daikin agent said, there is no protection to prevent series failure (i.e. fuse if compressor failed).

Have any of you with heat pumps not found

http://www.refrigeration-engineer.com/forums/forumdisplay.php?78-Heat-Pumps

?

Would you run a heatpump with rads for an annual cost as low as that?

Shanaknocker wrote: »

Thanks to all who have posted here, great source of information.

I am currently researching for a new build (220msq)and hopefully starting soon. I just received my parliamentary DEAP report and it states that i have a heating requirement of 4932 kwhr/yr and hot water requirement of 3560 kwhr/yr and a heat loss of 230kwper msq. I take it that if i divide 2932 by 220, il get kw per meter sq (22.418).
I just spoke with a rep and he suggest i use a 6kw Daikin Altherma integrated clinder (260 liter tank) with low temp rads (no more than 136 sections) estimating 10 k for installation including rads and pipework, with a cost of 3 to €400 a year.

does this sound right??????????



Sorry for picking you out CT98,
my rep seems quite approachable and has directed me in different directions in relation to other aspects. Have you approached where you purchased the product or gone directly to Daikin. What other issues have you encountered????
what system would you go for if not HP?

Water John wrote: »

Its down to the thermal envelope sealing and insulation of the house.
Yes about €400 tends to be the cost for HP plus UFH on a very good BER. Using Aluminium rads instead should make little difference.

It'll make a lot of difference. Alu rads will need 45C to be any good. You lose 2-3% efficiency for every degree increase so you'll be down at least 20% but more likely 30% in efficiency not to mention the extra strain on the compressor which means premature failure but I doubt the rep will mention that.

Water John wrote: »

30% of 400 is a diff of €150 in the year. To me that counts as a little diff.
I would not be expert on 'strain' on a HP. I thought they were pretty robust with little breakdown.
So would you very circumspect about the twin scrollers that also heat hot water to 55/60 C?

Personally, I would prefer UFH to Alu Rads.

Firstly, I would find it unlikely that you would heat that house with the mentioned unit for that money. Then you need to consider that the running cost will increase approx. 5% year on year so you start off at €400 or €550 depending on ufh or alu. Then the following year its €420 vs €577.5 and the year after that €441 vs 606.37 and so forth for the life of the unit with the spread getting wider by the year.


Regarding longevity. In order to increase temp you need to increase gas pressure which strains the components. In lay mans terms its like a guy going to the gym and putting 50kg on the bar and knocking out twenty repetitions but stick 70kg on the bar and he'll be done at 10 reps.A heat pump can handle low temp production all day but high temperature degrades the equipment quickly regardless of the compressor used. Heating water to 60C with any refrigerant other than ammonia or CO2 is madness and will destroy your heat pump in short order.

Water John wrote: »

Condenser, The second part of your post, I am not in a position to contest as it is not my area. But if what you say is true, then many manufacturers, including some very credible makers are being irresponsible.

In part one you are assuming an energy inflation of 5% per year. Doesn't matter what you heat the house with, that will apply.

Yes, I have been involved in supplying many clients with UFH and around €400 tends to be the cost of heating per year. Needs a good sealed envelope and high level of insulation but no insurmountable.

Yes they are but are you surprised. In the world of business anything can and will go in order to get a competitive edge. Theres very few moral companies out there.
My point about energy inflation is not that it increases, it is the fact that when your running costs are higher than they could be the increase is proportional to this higher cost and therefore becomes significant over the lifetime of the system. Same applies to comparing a GSHP to ASHP. Installation cost might be 3-4k more but half the running costs. When you work it out over the lifetime the savings are multiple times the initial investment.

Sheff, you just need to ask around to see if HP's are failing as being said by some posters.
Some installations would use UFH downstaires and alu rads upstairs.

Basically, talk to some plumbers.
I would like to hear further opinions on HP's too. I have an open mind on it.

Water John wrote: »

Sheff, you just need to ask around to see if HP's are failing as being said by some posters.
Some installations would use UFH downstaires and alu rads upstairs.

Basically, talk to some plumbers.
I would like to hear further opinions on HP's too. I have an open mind on it.

I worked in the area of Geothermal back 10 or 11 years ago, so I would have strong knowledge of the systems. However the following variables have changed

1.Insulation is now of a higher spec, meaning that the same heat requirement may not be there. Triple glazed windows were very rare back then.

2.Air to Water systems are a lot more common meaning that there is an alternative without needing a borehole or ground collector

3.Controls have advanced significantly

4.Aluminium radiators are very common now.

I accept that rads are used upstairs, but the heat requirement for bedrooms is not as demanding as for downstairs living areas.

Basically as pointed out by Condenser, the temperature requirement for underfloor heating is far less than for radiators. This means that the heatpump can run continuously without being stressed.

On the other hand, higher insulation specs these days mean that the same heat requirement is not there, so perhaps heating using radiators may not necessarily overwork a heatpump at all, even at a higher temperature. Lets say that underfloor requires 30 degrees heat and aluminum rads require 45 degrees heat. The reality is that the heatpump will have to work a lot harder to produce 15 degrees more heat and will cost more money to produce that heat

The big question then is on a winters day of say 4 degrees outside temperature, how long will the (possibly overworked) heatpump need to run for to heat the house using rads, and how long will it need to run (casually) to top up the heat in the ground?

Wouldnt mind seeing a setup where there are oversized rads throughout the house and a buffer tank in operation.

Ultimately even oversized rads would still need a higher temperature feed than underfloor

ferryman35 wrote: »

A heat pump can work fine with steel rads....if they are suitably sized - a larger rad running at a low temperature will deliver the same amount of heat to a room as a smaller rad operating at a higher temperature.

Efficiency falls as the temperature increases....for a gas or oil boiler as well as a heatpump - flow temperatures in the mid 30's to mid 40's should be easily deliverable with a heatpump - but you won't run a heatpump like you would a boiler on a start stop basis - whether it's heating through underfloor or radiators - cycling has a big impact on heatpump life and in this case a buffer can make a huge difference. With underfloor the screed is much like a buffer whereas with rads you don't have the screed to fall back on.

I've received quotes back from a few suppliers for ground source heat pumps and although I have given all the necessary information (including the DEAP xml file showing heat loss etc) they have all come back with quite different proposals.

The 1st has quoted for an 8.7kw Stiebel Eltron heat pump with a 400L hot water cylinder
The 2nd has quoted for an 8.3kw Waterfurnace heat pump and recommends getting a separate 300L hot water cylinder.
While the 3rd has quoted for an 6kw Thermia heat pump with a 180L integrated hot water cylinder.
Naturally the first has given me the highest quote and 3rd the lowest.

I intend using underfloor heating and as my heat loss should be close to passive levels (fingers crossed) I reckon the 6kw may be best to prevent the pump cycling on and off however the total water volume of 180ltrs has me concerned.

The house will be a 4bed with 1 main bathroom, 2 en-suites and a WC along with the kitchen and utility so while the 180L may be okay at present with only 2 occupants I think the 300L seems safer once kids come along and more washing etc is to be done.

The issue I have is that the 6kw has a lower SPF% compared to the others (396% vs 407% & 435%) so increasing the water volume with that pump affects my EPC in the DEAP file and causes me to fail.
I'm already assuming an air permeability of 1 m3/(hr.m2) @ q50 so I don't want to cut that any further incase I can't meet it.

Any suggestions on which I should go with?

I'm leaning towards going with the 6kw with the 180L tank and adding an additional buffer tank in a few years then if required.

ferryman35 wrote: »

There's another make & model out there that could be worth your while consider. The one I have in mind is an inverter model so it will modulate to your heat loss load anywhere between 2.5 & 12kw - but it takes the ground loop capacity into account so it won't be trying to soak 12 kw out or your ground loop if the loop can only supply 8kw. It's SCOP is 5.43 - and it has industry leading hot water capacity of 300L from a 229l buffer. Feel free to send me a pm if you'd like more information.

There is also a modulating ground source heat pump on the market with an SCOP of 6.6,
On the hot water tank, the best technology out there are fresh water systems, legionnaires free hot water without having to punish your heat pump compressor by forcing it to reach temps in excess of 60C adding years of life to the compressor,

http://www.aircon.panasonic.eu/GB_en/ranges/aquarea/ht/


Aquarea HT

For a house with traditional high-temperature radiators

Aquarea HT is able to deliver 65°C with the Heat Pump alone.
For a house with high temperature radiators (for example, cast iron radiators), the Aquarea High Temperature Solution is most suited as it provides output water temperatures of 65°C even at -20°C.

from here: http://www.boards.ie/vbulletin/showthread.php?p=100630544#post100630544

clarelady wrote: »

Hi
We are at final decision stages of deciding on a heat pump - we are going with atw and happy with that decision but not sure on which one. We are between daikon split integrated or a thermia atec both 11kw. Can anyone who has installed either let me know how they are performing and running costs and if they would recommend either. We are going with ufh downstairs and rads upstairs. Pm if need to
Thx

Check both the capacity and the temperature of the hot water systems in both.

If have a hot water cylinder you need it to be heated to 65'C at least weekly to prevent bacteria growing in the system. Some systems can do this with the heatpump but many use immersion heaters to do it.....i.e. significant running costs.


A split unit means that you have to get a Refrigeration Engineer to look after the gas, but he may or may not be able to look after the plumbing side...meaning that you may need 2 callouts (or a very good specialist) for repairs down the road.

Also check the defrost setup as this has a major impact on your running costs and heat delivery, just when you need it most - in cold damp weather!

There are other units that you haven't mentioned too!

Anyone heard of ES air to water heat pump? Swedish make . Anyone got it installed and how is it performing?? Any advice would be appreciated . New build heating system 2300sq ft house.cheers in advance

Philburns wrote: »

Hi, I have an SE AWH 9 kW – V5 retrofit. Had it for two years and am very happy with it so far. My house is an old cottage, well insulated in the roof but not particularly energy efficient, I imagine your new build will be much better energy wise.

Thanks for the info. How do you find the running costs.