Air to Water Heatpump

K

keptar

Guest
First post here

Was 95% ready to move on ordering an Air to Water heatpump to supply underfloor space and domestic heating requirements for new house we are building.

Yesterday, I met with a new installer of these units who advised that its very possible that unit will shut down completely on very colddays here. (and advised supplementary heat source would be required - oil boiler).

I've also looked at the more efficient ground source units, but would prefer not to dig garden or bore holes.

So this query is to users with A to W heatpumps installed over the last heating season. How sucessful was it? Did it shut down on any cold nights leaving house cold

cheers
 
Keptar

I have just found the air to water systems and am interested. Looks like the reduced efficiency is made up for by cheaper installation...
 
Keptar,
I attended a series of renewable energy day courses earlier this year, an energy control system consultant called Harry Rea (Cork) said his own personal choice in case of new build would be Water/Air H/P combined with a small oil burner - the H/P will suffice for 80% of the heat demand for the year but you would require oil some time during the colder spells, his area was control systems, its the most efficeient method of controlling the heat energy required in the house plus not that expensive ranging from €150 - €600.
 
DACMAN said:
Keptar,
I attended a series of renewable energy day courses earlier this year, an energy control system consultant called Harry Rea (Cork) said his own personal choice in case of new build would be Water/Air H/P combined with a small oil burner - the H/P will suffice for 80% of the heat demand for the year but you would require oil some time during the colder spells, his area was control systems, its the most efficeient method of controlling the heat energy required in the house plus not that expensive ranging from €150 - €600.
Click to expand...
Can you recall what his take was on ground source heat pumps ?
I wonder about solutions where oil burner is used to supplement
the main heat source. Seems like an inefficient way of doing things
but that's more gut instinct on my part more than any plumbing or
engineering wisdom. I guess small oil burner is the key here.
 
Ipxl,
The cost of Ground Heat pumps was in his view not justifiable when set against the other solution, the climate in Ireland happens to suit the Air H/P's - but he was not there to discuss heat pumps. FYI He also made the point that anyone building a new house should do the math & calculate their energy requirement for the house up front & spec rad' capacity plus u/floor (if rqd) to suit, combine with an automatic control system to reduce cost, apparantly the calculation of how many rad's ect required is seldom considered in any real detail - he is a plummer & has installed plenty of dodgy systems in the past. Also keep a close eye during build to ensure the structure is insulated properly, don't scrimp on the basic wall & floor & attic insulation install it correctly & it will pay back in short time. BTW the course was on making people aware of how to reduce energy usage as well as renewable sources.
 
I am currently building an ICF house in Meath and had chosen to go down the vertical ground source heat pump. The requirement was to drill 2 boreholes 125 metres deep. When they started drilling they got to 30 metres and all they found was gravel, clay and gravel so deemed it not viable for vertical drilling as the gravel would just fill the hole straight away.
We can't go horizontal, as we don't have enough room. Our supplier is recommending air to water, but I'm not sure. Any experience/ advice? We also have solar panels for our hot water and the house has underfloor heating on both floors.
Thanks.
 
has anyone any idea how much an air to water system would roughly cost for 2500sqft bungalow , plus does that include the grant
 
Im building a 2800sq ft ICF house. I got the following quote from Eurotec

1) Underfloor heating supply, install & comm: € 8,116 (ex VAT)
2) Eurosmart Heat Management System Supply & Comm: €3,619 (ex VAT)
3) Ochsner GMLW 14kW plus super split air to water heat pump €10,257 (ex VAT)
4) Collector Array fan split condenser & 300ltr buffer tank: €2,130 (ex VAT)
5) Eurogeothermal 65 deg C hot water production from heat pump : €1,150 (ex VAT)
6) Commission & Efficiency Test for 3,4&5 above: €800 (ex VAT)
7) Cylinder 300 Ltr 316 ss calorifier triple coil, supply of primary flow and return connections to calorifer heat exh, connec with pump and controls: €2,430 (ex VAT)
8) Plant room hyrdaulics €3,200 (ex VAT)

Total incl VAT approx €36,000

Can anyone tell me why this is so expensive?

Dgray
 
Hi,

Building a new build and have just switched on the air to water to supply under floor. It will be supplying rads too but we have have not turned these on yet as system is not fully set up. Initial review of unit is positive, runs quietly outside which was one of my concerns. A couple of points I would point out. Firstly, under no circumstance should you skimp on insulation - there is no point in investing in any heat system if all your good work is undone by drafts, poor insulation etc. Secondly, advise installing a dual tariff meter just to meter the energy usage during the night when you are likely to be using the system. Finally, your unit will have temp ranges within which it operates so will need the oil burner backup to kick in to bring the water temp up when temp falls below this range. Older units and shady installers, may try and use an imersion back up where you would see the electricity bill going through the roof. Our unit needs the back up for air temp below -5degree so can't see much demand for that.
 
Installed a thermia 12kw air source heat pump in our new build last year. System circulates warm water to the heat pump on very cold days to stop it freezing. First year has been great and we don't have a secondary heat source (other than stoves, but dependent on for heating house)
 
my father has an air to water heat pump for 12mths works great on ordinary rads never cut out, i think if the temp goes below -15c it might cut out, a great investment, A.G.H Energy in cork provided it at the best price.
 
try alternative heating and cooling, [email protected], ask for Mike Cotter he will explain the best solution with these and he has a lot installed. I have been to some of the houses and they have low bills to suit. They now have a "free energy" combination of wind turbine with air to water or geothermal which in combination reduces the cost of both and should give you 99% free heating and power !!!
 
dgray.ie. that quote seems excessive. our air to water heat pump cost €13000 last year (minus €2000 for the SEI grant). We got ours from nutherm and our total ESB/ airtricity costs (lighting, cooking etc) for the year was €1300. we have a night saver meter and run the heat pump at night with a couple of hours in late afternoon on very cold days.
 
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