Solar with Geo or not?

jasgrif11

HI All,

I've installed UFH in my house both upstairs and downstairs. This will be run off a NIBE Geothermal Heat Pump supplied by Ashgrove Engineering. I'm just wondering if I would need soalr panels aswell to heat my water? There will be 2 showers running off the geothermal boiler but will I have to use the immersion alot to boost my water temperature or will there be enough in the geothermal?

Has anyone installed both?

Don Pedro

Hi,

This doesn't help your question but wondered if you would be kind enough to give me any information on UFH.

Specifically, was it expensive to install (more so than gas fired central heating?)

Is it possible to install it under wooden floors (was told by "builders" it can't, only on tiles!!!)

Presuming you shopped around, where did you find to be the best place to go to?

Thanks a mil in advance,
Peter

yop

jasgrif11 wrote:

HI All,

I've installed UFH in my house both upstairs and downstairs. This will be run off a NIBE Geothermal Heat Pump supplied by Ashgrove Engineering. I'm just wondering if I would need soalr panels aswell to heat my water? There will be 2 showers running off the geothermal boiler but will I have to use the immersion alot to boost my water temperature or will there be enough in the geothermal?

Has anyone installed both?

We have Geo installed with UFH, both up and down stairs.

Personally I think it is over kill and a few installers also said that if you cannot install another alternative heatsource then you solar panels are a very good start, but that really your heatpump should be sufficent to provide all you heat and hotwater.

I don't know all heatpump setups but we dont have a seperate immersion. We have a 500 litre cylinder, the water is heated to the temp required for your UFH, then in our case, when a shower or hot tap calls for hot water, this water in the cylinder is pull through a gezer/immersion/heatplate and heated the extra degrees.

The apes who told you "only tiles" are not builders, send them back to creche. Of course it can be installed under wooden floor, carpets, tiles.
Tiles will transmit the heat the best, wooden floors next, then carpets are not recommended but you can still use them.

Both timber and carpet use special underlays though to all the heat to pass through. Not all timber can be used either.

Qwerty?

I'm in the same boat as YOP, ufh upstairs and downstairs running of a Geothermal Nibe heatpump.

I have an immersion in the tank, but haven't ever needed to use it in 19 months. We always have a tank of hot water. Solar panels would be great for the environment, if you can afford them aswell, but they are not needed.

billy_beckham

Yop and Qwerty,
can i ask what size in KW are your heat pumps,
how big are your houses,
what temp are you sending water out at to your UFH,
how long is your UFH running(As opposed to how long the HP is running..).

Cheers,
Billy

Qwerty?

Hi Billy,

• its a 13kw OUTOUT, can't remember the input, 4???
• 3500 sq foot
• varies by outdoor temp gauge, buy around 21-23deg C
• can't answer that one, because it's all automatic, the stats control that.

Q

yop

Billy

--9kw heatpump
--2100 sq foot timber frame
--28 degrees circulating temp, UFH set to 21 degrees, Dom hot water set at 40 degrees
--Cannot answer this, you mean how long is your circulating pumps running, unless you have separate meters on these you won't know

jasgrif11

Thanks Guys don't think I will go to the extra expense. I'll stick with just the heatpump my house is 3200sqft

billy_beckham

Thanks for the replies guys,
are ye really sending water out to the UFH at 20ish degrees? Is that just this time of year or all year round? How are you finding your ESB bills?

yop

Billy, generally you will find for most "factory fitted" UFH system that the flow temp is in between 35 - 40 degrees to achieve your 21 degrees room temp.

We were advised to tighten the loops to increase the coverage and therefore reduce the flow temp to 28 deg c.

I did my readings over a 15 week period up to the end of June and it worked out at 16 euro per week for the electricity for all heat, hot water and appliances

NewB08

Hi all,

I too am currently installing a GHP with UFH. Can I ask what size hot water cylinder you installed, one mentioned 500lits. My supplier recommends and supplies a 185lit hot water cylinder. I however have my reservations about the availability to supply hot water at peak times and have questioned this. However they guarantee me this is adequate and anything larger would only be required for guest houses. Also a M&E commented once that it is inefficient to heat a larger volume tank when the demand is not required. Does your hot water cyclinder meet your homes demands?

davgtrek

couple of things to note here.

the size of the cylinder depends on whether your hot water system is pressurised or not. a lot of people put a 3 or 4 bar pump onto water system and that gives a pressurised system. it will use more water but all taps/showers become a power shower etc. go with a stainless steel 600litre cylinder. these cylinders are super efficient and act like a flask with most loosing only a few degress of tem over 24hrs.

Get a master mixing valve put onto the hot water coming from the cylinder.
this is a thermostatic device that you set and it will prevent scalding. it works like a thermostatic shower device but is slightly cruder.
make sure you bypass the utility & kitchen sink supply from this valve to get hot water for washing etc.

underfloor can be used with floorboards. Despite what the installers say the science of this is flawed. It will work perfectly efficiently with tiles but timber is a natural insulant. would you coat a radiator in rubber and expect it to work well. the floor will work but with timber floorboards no matter how thick it will not be anywhere as efficient as through tiles.
Underfloor is only borderline on the efficiency charts anyway as its reaction time is slow and longburning to deal with the irish variable climate. anyway that sounds a little prejeduced against ufloor but from a building materials perspective you dont usually put insulation between the heat source and the room air.

solar panels: they are effective at what they do and leaving their initial outlay aside provide free heat. Their advantage is that they can work on the cold water in the cylinder to get it to its first 30-40 degrees which is the more energy sapping than getting it the final 20-30 degrees which the heatpump or oil burner will do.

HOWEVER: with the highly efficient cylinder mentioned above a standard oil burner would take a max of 1 hour to heat it to the typical 60-70 degrees. An oil burner typically uses 1/2 to 1 litre per hour.
so thats say 70c per fill. a cylinder that size with timed water heating in morning should do for the day with little else needed. so say it needs a bit more heat later in evening. at most thats €1 per day to heat water.
so thats €350 per year in oil.

typical solar panel setup even with grant might be 3-5k.
say €4000 / €350 = 11 years of oil at current prices.
even if oil doubles then thats still a 6-7 year payback.
though probably more like 10.

modern boilers/heatpumps and a good cylinder will easily lash out hot water for very little cost.
that was my rational for determining my setup at home.

make sure that a new cylinder has at leats a dual coil.
1 coil takes main boiler. the other can take an alternative heat source like solar panels or pellet boiler or whatever.

i would recommend people to look at a "systemlink" zoning box if planning their heating system around radiators. its a simple plug and play box that contains the thermostat valves & zone pumps ( ie. brains of heating system ) that the plumber simply plugs his rad pipes into and the electrician wires up.

it will stop all the head scratching of plumbers and electricians wiring pumps, valves, thermostats and then blaming each other when it goes wrong.

p

davgtrek

careful heatcraft. you'll get hit with an infraction by the moderator.

that technology sounds very good.

€1500+ for a 3600f2 house sounds excellent. I am skeptical though at an average esb bill of €250+ all in. that must be a very highly insulated and efficient house.

p

yop

So how large are the cylinders you use heatcraft? If you supply a 300 litre cylinder, do you heat it all to 60 degrees?

So you are saying that it costs 112 euro per month for the heating costs!!! Thats sound insane to be honest. How much would the unit cost be on top of that, 20/25k euro?