Heat Pumps - post here.

BryanF

ive moved this post here. Don't spam posts thanks

speedstar500 wrote: »

Hi, Can anyone advise on the best brand/model of air to water pump? I have received 4 quotations all of which advise a 14kw pump but all brands are different and there is a €5,000 difference form cheapest to most expensive. Brands quoted were Panasonic, danfoss, dimplex and hitachi.

Many thanks

sheff the ref

speedstar500 wrote: »

Hi, Can anyone advise on the best brand/model of air to water pump? I have received 4 quotations all of which advise a 14kw pump but all brands are different and there is a €5,000 difference form cheapest to most expensive. Brands quoted were Panasonic, danfoss, dimplex and hitachi.

Many thanks

€5000 is a significant sum and you could be paying for a label or just as equally paying for a better product. I recommend seeking out people who have those models in operation for a year or two at their homes. Seek references from the supplier

newbieboarder

Hi all,
Re Thermia and Nibe air to water heat pumps.

We now have to make a decision on which one of these air to water systems to use--both are coming in at approx the same price---we are doing full house renovation with super duper insulation (or so we are promised), underfloor heating everywhere downstairs, and rads running at a low temperature upstairs.
Can people with experience of using either system PLEASE help us with this decision, as we want the system that is easiest for us to control/change as/if required, (although my husband is great at reading user manuals unlike me), and has a good track record on longevity, and also has good service technicians available if problems arise???

murphy31ie

Hi,
Does anyone know what the Envision ground source heat pumps are like, thanks in advance for any info.
Cheers

wofman27

I'm about the start building a 2206sq Foot House in Donegal, beginning of April
Looking to install Air to Water Heat Source Pump. Has anyone one of these installed recently? What have your electricity bills been like to date?
What supplier have you gone with and how has the system worked for you?

I have being quoted at €16k for installation of Air to Water by two different suppliers
One supplier came back at €28k plus vat!!!!

Decided to go with A2W as Geothermal coming in at €20k average with horizontal piping on land, and an extra €3k for vertical drilling if ground isn't suitable.
Geothermal a no go as the budget is stretched as is!!!

Any feedback or advice would be great.

jodaw

Have you researched the Air To Water heat pumps thoroughly and are you happy to go with that. There seems to very few of these installed in Ireland.

I would prefer the piped solution for our climate.

I would get extensive references from the supplier regarding previous installs and check them all out very carefully before proceeding.

wofman27

hey jodaw

i have been researching like crazy on all these systems, head wrecking to say the least.
I went to see an installed A2W system in operation at the weekend,
and was quite impressed by what i saw, he was calculating running costs etc on this.
My preference would be geothermal, but it is out of my price range

BryanF

Threads merged

MENACE2010

Hi Wofman27
it has been debated here in this post for quite a bit .. its all depending on what the heat requirement is for your house ,.. my house is different to yours in all aspects ( size, location , orientation etc etc ) so its hard to get a grip on what it will cost.
I was in the same dilemma .. went for air-source in the end, for the same reason. The only advise i can give you is to insulate the house you are building to what you can affort and can do at this stage ( triple glazing , insulated plasterboard etc etc. get creative and avoid draughts in your house )

At the moment int the last 4 months november - february the electricity bill has come in at 1000 euro for everything for our house . .250 euro per month for everything .. ( TV, fridge , freezer, Heatrecovery ventilation , washing maching , dryer , dishwashere.. ovens .. ) I know from now on the bills will get lower and lower.. until the winter comes around.

now.. there is no oil to content with .. I have lived in a house ( rental) that literally was using oil like it was going out of fashion..
I'm happy with it .. still trying to tweak the house ( nearly two years in the house) to get the optimum temperature ..

PM me for details ..

sheff the ref

How much of that €250 ESB per month is being consumed by the heat recovery ventilation?

badgerhowlin

MENACE2010 wrote: »

Hi Wofman27
it has been debated here in this post for quite a bit .. its all depending on what the heat requirement is for your house ,.. my house is different to yours in all aspects ( size, location , orientation etc etc ) so its hard to get a grip on what it will cost.
I was in the same dilemma .. went for air-source in the end, for the same reason. The only advise i can give you is to insulate the house you are building to what you can affort and can do at this stage ( triple glazing , insulated plasterboard etc etc. get creative and avoid draughts in your house )

At the moment int the last 4 months november - february the electricity bill has come in at 1000 euro for everything for our house . .250 euro per month for everything .. ( TV, fridge , freezer, Heatrecovery ventilation , washing maching , dryer , dishwashere.. ovens .. ) I know from now on the bills will get lower and lower.. until the winter comes around.

now.. there is no oil to content with .. I have lived in a house ( rental) that literally was using oil like it was going out of fashion..
I'm happy with it .. still trying to tweak the house ( nearly two years in the house) to get the optimum temperature ..

PM me for details ..

I aggree with you there MENACE2010 every house is different.
BUT €1000 for 4 months is almost my entire years ESB bill and im running a vertical HP in a 208 sqm house
I can safely say that my HP only used about €180 out of my €490

wofman PM me if you want I have breakdown on cost for running and installing of my system. My systems was only half of the quote you got.

MortgageBroker

MENACE2010 wrote: »

Hi
we have night tarrif.. we have on the ground floor from the foundation up > 200MM EPS insulation with 75MM screed on top of that..

Who was your installer? I can't get anybidy who can do a call out in dublin

phobia2011

can a heat pump be sized by using ufh loop length/manifold size? its the only info i have of dwelling?

Dartz

jodaw wrote: »

Have you researched the Air To Water heat pumps thoroughly and are you happy to go with that. There seems to very few of these installed in Ireland.

I would prefer the piped solution for our climate.

I would get extensive references from the supplier regarding previous installs and check them all out very carefully before proceeding.

Over the life of the system A2W wins out through the simple virtue of being much cheaper to install, always. And it'll run just as good if the designer has his head screwed on.

Most A2W heat-pumps will run down to -20 degrees air temperature - more than enough for an Irish winter.

Condenser

Dartz wrote: »

Over the life of the system A2W wins out through the simple virtue of being much cheaper to install, always. And it'll run just as good if the designer has his head screwed on.

Most A2W heat-pumps will run down to -20 degrees air temperature - more than enough for an Irish winter.

So just ignore the fact that they're far more expensive to run than a GSHP and that they have a far shorter life time? What's the COP on your average A2W heat pump at Air 0 and Air -5 may I ask?

Condenser

phobia2011 wrote: »

can a heat pump be sized by using ufh loop length/manifold size? its the only info i have of dwelling?

No you could possibly work out what's the max size heat pump you'll get away with on the loop but that won't determine whether its oversized or undersized for the house. For that you'll need the insulation specs etc.

Charlie Charolais

hi guys,

What is the most efficient way to get domestic hot water from 35* to 55*?

We have (nearly) decided on air to water HP, so UFH @ 35, the side tank will get DHW to 35,
Plenty companies quote COP at 35 but none quote COP at 55, what are they hiding, is it inefficient from 35 to 55?

Add a solar panel, an immersion of some sort?

We ask now because if it is a solar panel we have to hip the south roof, so will this will have an affect on planning permission application

Addendum:
we add an elec immersion to DHW tank, the elec immersion only kicks in when A2W stops working say (preset at -5*), can you back feed the UFH from the DHW tank heated by the elec immersion?

Your advice would be appreciated

Dartz

Condenser wrote: »

So just ignore the fact that they're far more expensive to run than a GSHP and that they have a far shorter life time? What's the COP on your average A2W heat pump at Air 0 and Air -5 may I ask?

What sort of A2W heat pump are you thinking of? One of those fat old yokes that suck 6 and a bit kW through a single speed compressor and has exactly two settings ('Off' and 'On')?

Or a system that's actually designed properly by competent engineers, using a inverter driven compressor that can be run at a speed that isn't full bore all the time?

And where does this shorter life-time FUD come from?

A2W requires a bit more care with the design side, but if the design team's doing their job right with the controls and the heating system it's attached to, then you're never going to make up the cost difference.

What do you think it'd cost to heat a new-built 2000sqft house - built to current regulation standards - using an air to water system, with an immersion backup? Gimme an annual estimate for a year.

Condenser

Dartz wrote: »

What sort of A2W heat pump are you thinking of? One of those fat old yokes that suck 6 and a bit kW through a single speed compressor and has exactly two settings ('Off' and 'On')?

Or a system that's actually designed properly by competent engineers, using a inverter driven compressor that can be run at a speed that isn't full bore all the time?

And where does this shorter life-time FUD come from?

A2W requires a bit more care with the design side, but if the design team's doing their job right with the controls and the heating system it's attached to, then you're never going to make up the cost difference.

What do you think it'd cost to heat a new-built 2000sqft house - built to current regulation standards - using an air to water system, with an immersion backup? Gimme an annual estimate for a year.

Plenty of ground source heat pumps with inverter compressors too but to state that a fixed speed is somehow inferior is nonsense. What "fat old yokes" are you referring to exactly, you're being too technical for me there.
Air to water systems have an inherently shorter lifespan due to a number of factors
Exposure to varying weather conditions repeatedly
Components exposed to extremes of weather (including inverters and compressors)
Cheap units are built with a finite lifetime built in, even the metals in high end units will have noticeable degradation after 10yrs. Cheaper units long before this.
Coil failure due to thermal shock from repeated reverse cycle defrosting
(should I continue)


They are also inherently less efficient
Efficiency drops with outside temp i.e. least efficient when needed most
Icing (a2w units progressively get less efficient from the moment they start to the moment they defrost)
Defrosting, removing energy from the home for no net return
Fan motors, far more energy hungry than circulating pumps
(and the list goes on)


Running costs will depend on the quality of A2W unit so giving you a running cost of an A2W is pointless, but even the best units aren't in the same league as GSHP's and they will cost just as much to buy in the first place. Come back to me when you get those COP stats

Dartz

And yet, the running costs are the most important factor. What is the difference, annually, between heating a house with A2W, and Ground Source, assuming all other factors are the same? Because that'll determine just what the economics are.

Now then, account for the fact that you have to go out and dig and lay down pipework for the ground source - and that's not a small amount of pipe to both pay for and install. How long will it take the difference in annual running costs to catch up.

All of the rest of what you're spreading is just FUD. A good, properly designed A2W pump will have none of the reliability issues you mentioned.

Condenser

Dartz wrote: »

And yet, the running costs are the most important factor. What is the difference, annually, between heating a house with A2W, and Ground Source, assuming all other factors are the same? Because that'll determine just what the economics are.

Now then, account for the fact that you have to go out and dig and lay down pipework for the ground source - and that's not a small amount of pipe to both pay for and install. How long will it take the difference in annual running costs to catch up.

All of the rest of what you're spreading is just FUD. A good, properly designed A2W pump will have none of the reliability issues you mentioned.

A well thought out, informative and considered reply. Thank you for tearing my post apart and dispelling any spurious notions I may have had

seaniefr

Dartz wrote: »

And yet, the running costs are the most important factor. What is the difference, annually, between heating a house with A2W, and Ground Source, assuming all other factors are the same? Because that'll determine just what the economics are.

Now then, account for the fact that you have to go out and dig and lay down pipework for the ground source - and that's not a small amount of pipe to both pay for and install. How long will it take the difference in annual running costs to catch up.

All of the rest of what you're spreading is just FUD. A good, properly designed A2W pump will have none of the reliability issues you mentioned.

Funny you should root for A2W- i have an A2W and all things considered i would stump up the money for vertical bore ground source if i was to do it over again. After a couple of hard winters you soon realise that while very efficient and all the rest......nobody has gotten over the simple little fact that A2W's are hopelessly inefficient when the outside temp is below Zero degrees and there is no getting away from that very simple fact. They basically use more electricity the closer the outside temp gets to Zero. In other words the COP goes out the window and they basically become a big heating element.

BarneyMc

seaniefr wrote: »

Funny you should root for A2W- i have an A2W and all things considered i would stump up the money for vertical bore ground source if i was to do it over again. After a couple of hard winters you soon realise that while very efficient and all the rest......nobody has gotten over the simple little fact that A2W's are hopelessly inefficient when the outside temp is below Zero degrees and there is no getting away from that very simple fact. They basically use more electricity the closer the outside temp gets to Zero. In other words the COP goes out the window and they basically become a big heating element.

I'm begining to doubt my choice of going with A2W (although I've still time to reconsider). When did you install your A2W HP and is it a reputable make?

seaniefr

BarneyMc wrote: »

I'm begining to doubt my choice of going with A2W (although I've still time to reconsider). When did you install your A2W HP and is it a reputable make?

3years ago. Oh don't get me wrong it does exactly what it's supposed to i It's just when we have a string of nights below zero you basically have a very expensive immersion( back up heater) . Like I said in the original post if I had it over again would go for vertical bore gshp. Steady electrical bills very little weather variation. You end up putting money into stoves or whatever to make up the difference so you have to factor in all that as well. Basically if the outside temp never got below 4 then they are fine but then again this is Ireland.......

BarneyMc

seaniefr wrote: »

Like I said in the original post if I had it over again would go for vertical bore gshp. Steady electrical bills very little weather variation. You end up putting money into stoves or whatever to make up the difference so you have to factor in all that as well. Basically if the outside temp never got below 4 then they are fine but then again this is Ireland.......

Why vertical bore? Do you not have the space for horizontal?

I'm lucky to live on a farm and have 'free' logs so this might help me get through the colder spells. I will be installing a log burning stove.

Do you run the HP on night rate electricity or is it better to run it during the day on full rate but warmer conditions?

seaniefr

BarneyMc wrote: »

Why vertical bore? Do you not have the space for horizontal?

I'm lucky to live on a farm and have 'free' logs so this might help me get through the colder spells. I will be installing a log burning stove.

Do you run the HP on night rate electricity or is it better to run it during the day on full rate but warmer conditions?

Vertical bore cause I want to put something into a home and not have to worry that I might accidentally dig it up gardening or whatever and besides that much better frost protection. I run on night rate only no day rate. If I left it on during the day it would be the equivalent to leaving the immersion on all day. I am on a half acre site it would have meant at the time uprooting everything to bury the pipe which I thought was mad. You can just bury the bloody thing in a field😄

seaniefr

BarneyMc wrote: »

Why vertical bore? Do you not have the space for horizontal?

I'm lucky to live on a farm and have 'free' logs so this might help me get through the colder spells. I will be installing a log burning stove.

Do you run the HP on night rate electricity or is it better to run it during the day on full rate but warmer conditions?

Barney have you underfloor heating or are you just using aluminium rads?

BarneyMc

seaniefr wrote: »

Barney have you underfloor heating or are you just using aluminium rads?

Will be installing UFH Seanie. There are so many variables here like type of heat pump, PV cell payback, floor thickness, floor type (liquid screed or sand/cement)...

seaniefr

BarneyMc wrote: »

Will be installing UFH Seanie. There are so many variables here like type of heat pump, PV cell payback, floor thickness, floor type (liquid screed or sand/cement)...

Probably the best I have seen done was where it was installed between floor joists its a lot more work (isn't it all lots of work) mine is in a 4" screed but if the guy doing your sub floors is not 100% accurate then you have more concrete to heat as your floor slab will basically be one big heat exchanger or storage medium (in each room) or whatever you like to call it. The a2w hp is really good with UFH will say that for it. Mine has a climate control setting where it reacts to the outside temp so if the temp is high during the night then the system only runs at a low temp and if the temp is lower the hp works harder you get the picture anyways. I think the heat pumps are the best fit with the ufl to be honest just make sure what ever you get has a soft start / inverter control on it or you will be dimming the neighbour lights when it starts up. I guess the biggest sticking point with all this renewable technology is the payback time as it will probably take at least 10-15 years to get a return on investment through savings generated less any repairs of course!

BarneyMc

seaniefr wrote: »

Probably the best I have seen done was where it was installed between floor joists its a lot more work (isn't it all lots of work) mine is in a 4" screed but if the guy doing your sub floors is not 100% accurate then you have more concrete to heat as your floor slab will basically be one big heat exchanger or storage medium (in each room) or whatever you like to call it.

Not sure I follow Seanie. Regarding the floor joists I assume you mean the first floor?

Also are you saying that in some places the floor may be greater than 4"? What's the problem with that - why is 4" the magic number? I'm thinking of using 3".

Also is the sub floor not supposed to act as a heat exchanger/storage medium?