Heat pump decision

Jeez you need to chill. Someone told me about the site at work - I saw this thread and thought I would offer some real experiences of someone that has done this for themselves. I will probably contribute to other threads, when I have time. The surface power URL is just information again take it or leave it. I'm a punter ! - I work in software development and have no connection with any supplier of any sort. If you are really that sceptical of boards like this you shouldnt bother reading them. I live in Mullingar so if you really want to see what its like you can come see for yourself - I'm not an axe wielding murder either just a brit living in Ireland with my kids and wife! Not heard, experienced ground freezing, the ground is a constant temperature around 7-8 degrees at the depth you need to bury the collector pipes at - the heat the collectors take out is not sufficient to start freezing soil 3 feet above it ! Yes I would agree with insulating above the norm hence my comment about triple glazing if you can afford it.

Mark -

Apologies about the tone of my reply earlier in the week.
I really didn't mean to cast any aspersions over your genuineness,etc.
You can be sure that I've chilled since then. Maybe it was the onset
of the hot weather -- anyway I've had some cool mineral water
now! Hope you are enjoying the hot weather in the midlands
yourself by now.

I've no problems with URLs. You said you have a NIBE pump.
Who installed the system - if you don't mind me asking ?
I'm 99% sure I will go with the NIBE heat pump also and I've
gotten a quote from EIL in Sligo and I've seen two systems
installed by them with happy customers (the householders
are people I know from my social circle and not folks who
EIL told me to go to..)

The system is pretty expensive to install nonetheless.
26k Euro (subtract 4.5k approx for grant approval) without
including the hire of digger and 80m x 18m x 1m trench to
excavate and fill. It also doesn't include the xtratherm or
kingspan insulation for both floors or any special underlay
required for the UFH which sits above the screed once
the screed is dry and semisolid floor goes above. It doesn't
include the pouring of screed. It doesn't include installation
of a night rate ESB meter (necessary for the economics
of the payback calcs).

I spoke with a plumber who does know and understand UFH
and he was still in two minds as to whether to go for
gshp or to put in a high spec condensing oil burner and
sit it out for a year or two while the alternatives energy
market in Ireland's climate became a little clearer.
I personally think the payback period on the gshp is longer
than most are making out but I do believe it will payback.
My only concern is if the payback period is long enough
that it might coincide with increased possibility that the
HP might need replacing or extensive servicing which would
render the payback calculations invalid for another while,etc.

thanks again for providing your figures Mark. Apologies if
I got a bit hot under the collar with frustration earlier
in the week !

~ipl

Guy based in Cavan installed our system - he now does a lot of the renewable energy source stuff solar, wood chip etc - the only problem he has is time at the moment, hes swamped. I will happily give you his number if you want it.

Ours worked out at 23K - and from memory all the extras you mentioned like screed, xtratherm upstairs downstairs,digger, night meter wasnt included, we didnt have the luxury of the grant. either ;o(

One of the reason we liked NIBE is its very well proven in the Skandinavian market. I think you are probably right about exagerated payback dates by some people - I figure 5-7 is reasonable with oil going up 20% last year alone. Having said that ESB also went up a good bit which is why I'm looking to supplement with another renewable source. If you are in Sligo then ideal location for wind !

Couple of links re reliability - all good news from what I can see.


http://www.heatpumpnet.org.uk/

Thanks v.much for details Mark.

The first of those links gives a very clear and succinct explanation
of the gshp technology as it applies in this neck of the woods.

One thing that bothers me a bit is the whole domestic hot water
heating explanation. According to that article the 40degree or
so pumped heat which is used to feed the house central heating
requirements may not be enough on its own for DHW. I've spoken
with two distinct families who have installed the system and like
you they seem to be doing fine with DHW as a byproduct of the
heatpump. I know that the cylinder they tend to install has an
immersion heating element as part of backup but in reality (in
just basic physics/engineering terms) how does the DHW reach
a temperature suitable for showers/basins,scalding for rinsing
things at a kitchen sink,etc ?

The other thing that still gives me heebiejeebies is the collector
pipes buried in the ground. Sure, lets ditch this whole concern
about them freezing over but.. 40 years time. Ok I'll be 80 by then
but the thoughts of the lovely lawn (we have 1.2 acres some
of which will be maintenance free but rest will be seeded for
back lawn,etc) being ripped asunder to replace ageing collector
pipes isn't a nice thought for me to savour. Did your installer
give you best/worst lifetime estimate for the collector piping ?

~ipl

We installed a bigger than normal (VPA 300/200- Nibe recommended) tank the hot water produced by the heat pump is enough for me,wife and 3 kids ie 2 showers (minimum) a bath and other general household requirements - we regularily have more 2-4 adults staying over a weekend all wanting showers and never have an issue with hot water - we do have an immersion facility as well - too be honest I couldnt tell you if the hot water side of things is due to the heat pump of the immersion kicking in when it needs to -
another good link on the same site I sent u earlier if you havnt already found it is



gives good overview - its synopsis is basically no one solution is going to be perfect but using a combination of technolgies now can work. You could wait for some of the hybrids solution they hint at but I figured I 'm not moving from here for a long time and investing in a GSHP and UFH is not going to be a bad investment - the lake view is tooooo good as well ;o)

Collector pipes lifetime ? It wouldnt be keeping me up at night.

Anyone got any experience with air/water heat pumps? They seem to be slightly less efficient, but much cheaper to install.