Heat Pumps - post here.

murphaph

gooner99 wrote: »

Thanks for the reply. Yes if we go this route we will ensure the underfloor is set up so as it can take a heatpump. I'd imagine that once the underfloor is set up the correct way, then you can simply add in a different heat source in the future.

Yeah I see no problems with that. Friends of ours here in Berlin are doing just that. They really want a gshp but their budget is tight, so they're going for a high efficiency gas boiler for now. In 10 or 15 years they'll install their heat pump when finances permit.

gooner99

murphaph wrote: »

Yeah I see no problems with that. Friends of ours here in Berlin are doing just that. They really want a gshp but their budget is tight, so they're going for a high efficiency gas boiler for now. In 10 or 15 years they'll install their heat pump when finances permit.

Thanks for the reply. I'd imagine once the underfloor is in place changing should be pretty straight forward.

flutered

exaisle wrote: »

I've seen geothermal systems use rivers as heat source, just wondering if it would be feasible to use seawater? Minimum temperature of around 8-10 degrees...

i seen one recently on tv, a guy in jersey was using one powered by sea water to dry seaweed, which was contained in something like a massive grow house, it was one of the phenelope keith programs where she visit places all over britan

gooner99

flutered wrote: »

i seen one recently on tv, a guy in jersey was using one powered by sea water to dry seaweed, which was contained in something like a massive grow house, it was one of the phenelope keith programs where she visit places all over britan

Note sure I'd want to be trying something that's not proven. From reading around it seems that Geo is the way to go and A2W should only be considered as a last resort, especially in a coastal location. But also if you go passive or near passive the running costs of using a heat pump of any kind instead of oil or gas with underfloor diminishes and the payback time gets much greater. Of course if oil/gas skyrocket then it's a different story. Also there is the argument of not having another utility and never have to bother ordering oil/lpg.

Seems the fastest payback of a heat pump v oil/lpg funnily enough seems to be on a poorly insulated house!

antoinolachtnai

It depends on the size and type of the heat pump you put in surely?

I would say air water is more viable beside the sea because air temperatures never go that low there. It is always a couple of degrees warmer than inland.

Any ground source setup is going to have very high capital costs.

A small air water setup is pretty cheap.

The problem is really that passive houses only really need heat on the coldest days when air temp is lowest. Geothermal will have better temperatures but unless you live in a stately home the capex is very high compared to the heat requirement.

If you really want to analyse it, it may well turn out that storage heating or underfloor heating with electric elements in the slab is actually going to be the cheapest way to heat a passive house.

And if it gets really cold turn on a few fan heaters or even the electric oven. They will heat it up pretty quick.the heat is not cheap but you will only need it for a few days a year, and the capex For 15kw of heat is practically zero.

Electric heating is environmentally sustainable if timed to run outside the high demand time and when wind is blowing.

saibhne

Hi have a look at the AirGo heat pump - very suitable for coastal locations. 20 year warranty on the evaporator.


http://glenergy.ie/wp-content/uploads/2017/02/Air-GO-Corrosion-resistant.pdf

S.

saibhne

Hi have a look at the AirGo heat pump - very suitable for coastal locations. 20 year warranty on the evaporator.


http://glenergy.ie/wp-content/uploads/2017/02/Air-GO-Corrosion-resistant.pdf

S.

gooner99

saibhne wrote: »

Hi have a look at the AirGo heat pump - very suitable for coastal locations. 20 year warranty on the evaporator.


http://glenergy.ie/wp-content/uploads/2017/02/Air-GO-Corrosion-resistant.pdf

S.

Interesting. It seems to work in combination with a horizontal loop.

http://www.jifon.se/en-2/enairgo/

Anyone seen this in action?

MENACE2010

sheff the ref wrote: »

How is this experiment going for you now?

Hi
Quite well , the pumps is not going "like mad" in the morning .. usage is marginally different in operational hours and the pump seems to in use less in this mode as its only looks to top up .. the difference rather than making it up in the time allotted.. house overall is more comfortable.

What I do miss, and if there is anyone out there that has some "smart" stat or logic that can work with the weather. for example with underfloor the floor is already "charged" with heat in the morning while the sun comes out in the afternoon the house still gets too warm ( even in the winter)

Water John

Heatmiser Thermostats calculate what time it took to heat the house on previous days.
For example if you drop back heat levels overnight. it will begin warming up when it needs to to get you to optimum setting for when you get up.
There are also Weather Compensation thermostats, that gauge outside conditions for your HP.

That's one thing I would not be able to tolerate with underfloor heating. The changes in weather you get here.

How about air to water pumps ?

This is where I could see value in the likes of the Tesla storage battery, charge your battery on night rate and use it to run the heat pump during the day.

KCross

Deleted User wrote: »

That's one thing I would not be able to tolerate with underfloor heating. The changes in weather you get here.

Why?

Its called weather compensating controls to do exactly that which is to change based on the changing weather. You dont even "see" it happening. It keeps the temp in the house constant which is surely the point of every heating system.

Water John

The better way is to use a large insulated water storage cylinder 1/2000 ltr.
Use HP at night to heat this. Thus no cutting in and out, which is good for a HP.
Use a secondary loop with impeller pump to heat the UFH.

antoinolachtnai

The wholesale price of electricity in the afternoon before 4pm is pretty cheap. That is when the temperature is probably highest and so when heat pumps will be most effective.

Solar PV will make afternoon electricity even cheaper.

Water John

Agree with you, that Solar will make afternoon possibly the cheapest time, when the Govn't gets around to it.

Possibly the next Govn't or the one after that.

antoinolachtnai

antoinolachtnai wrote: »

Solar PV will make afternoon electricity even cheaper.

Sure , for the ESB, all the excess given to them for free.....

KCross

KCross wrote: »

Why?

Its called weather compensating controls to do exactly that which is to change based on the changing weather. You dont even "see" it happening. It keeps the temp in the house constant which is surely the point of every heating system.

That's fine if it works and you don't have to open windows.

KCross

[Deleted User] wrote: »

That's fine if it works and you don't have to open windows.

If you're opening windows it was installed wrong.

antoinolachtnai

Water John wrote: »

Agree with you, that Solar will make afternoon possibly the cheapest time, when the Govn't gets around to it.

Possibly the next Govn't or the one after that.

It really depends on the metering arrangements, i.e., smart meters. It's already pretty cheap.

The average wholesale price (well, the SMP) was 39 euros/MWh between 1pm and 3pm last year. That's half the rate between 5 and 7 pm, more or less.

The average price between 5 and 7 in the morning wasn't much cheaper, at 31 euros/MWh. Distribution charges are also cheaper at night, but that is just an arbitrary charge that could be changed.

Rushy Fields

Hi all,
I have a NIBE 1145 GSHP in utility and want to turn off heat.....
The scheduling is on at the moment Shedule 1 is 00:00 to 07:00am 20C. Schedule 2 is 17:00 to 19:00 20C. Using Heating curve 0.
Do i just disable the scheduling o do i have to change some other settings?
Hot water heating is at normal setting and is Prioritized at 5am to 7am if required.
I was thinking of maybe changing the heating curve also......

Any Advice welcome.

Thanks

KCross

Rushy Fields wrote: »

Hi all,
I have a NIBE 1145 GSHP in utility and want to turn off heat.....
The scheduling is on at the moment Shedule 1 is 00:00 to 07:00am 20C. Schedule 2 is 17:00 to 19:00 20C. Using Heating curve 0.
Do i just disable the scheduling o do i have to change some other settings?
Hot water heating is at normal setting and is Prioritized at 5am to 7am if required.
I was thinking of maybe changing the heating curve also......

Any Advice welcome.

Thanks

The system will automatically turn off space heating once the 24hr outdoor temp average goes above a set value.

You can change that cutoff point via the menu. Off the top of my head, its in a menu called "auto mode setting" and its a degrees celsius figure you are looking for (something like "stop heating"). Reduce that value to cause the system to turn off space heating sooner. I have mine set to 13C so once the average outdoor temp over a 24hr period exceeds 13C the system will turn off space heating automatically and continue to heat hot water.

And obviously, when it gets cooler later in the year it will automatically come back on.

I wouldn't mess with the heat curves or other settings. Just get that cutoff temp set to your liking and then the system doesn't have to be messed with twice a year.

Rushy Fields

KCross wrote: »

The system will automatically turn off space heating once the 24hr outdoor temp average goes above a set value.

You can change that cutoff point via the menu. Off the top of my head, its in a menu called "auto mode setting" and its a degrees celsius figure you are looking for (something like "stop heating"). Reduce that value to cause the system to turn off space heating sooner. I have mine set to 13C so once the average outdoor temp over a 24hr period exceeds 13C the system will turn off space heating automatically and continue to heat hot water.

And obviously, when it gets cooler later in the year it will automatically come back on.

I wouldn't mess with the heat curves or other settings. Just get that cutoff temp set to your liking and then the system doesn't have to be messed with twice a year.

Thanks for the info KCross will have a look at the system when i get home later

top_dog

Hi all,
I have an old stone two-story farm house which I am going to get renovated. I currently have an oil boiler with rads and it's very expensive to heat house currently and actually doesn't heat house adequately in cold weather. There is poor quality windows and roof insulation. I plan to upgrade windows and roof insulation. But just lime plaster the walls. 
I am thinking that if I go with UFH with a2w or ground heat pump the stone walls and the screed will provide good thermal mass and would be the best option for heating house.
I have been told by the experts that the a2w and ground are very similar with regards to efficiency. They also say that you need good insulation which I may not have in the walls. Although the walls are more than two feet thick so they should have good thermal mass. 
I read online though that ground has a better SPF value. In this example with stone house what would be the best option? Ground or a2w? I would run the heat pump on nighttime rate electricity. I believe the lower the outside air temp the less efficient the a2w heat pump? Therefore my feeling is if I am running at nighttime rate elec I would be better to go with ground as it would have a better COP at nighttime. Would anyone agree with this? 
I hope to hook up the oil boiler as a backup as I currently have oil boiler. Does anyone recommend doing this?
If you don't think that an a2w or ground source heat pump is suitable for this house I'd be interested to know what heating system you think is suitable? 
Any advice would be very welcome. Thanks!

I have an efel oil stove and the heat out of it is unreal. One that heats the rads and one in the sitting room and you'll have all the heat you'll ever need and they're very efficient. There are idiots getting rid of them for much more expensive solid fuel and I highly recommend the oil stoves and you can get them cheap as chips 2nd hand as no one seems to want them any more.

Heat pumps are grand but you need a very well insulated and air tight house which is expensive to obtain and heat pumps are a huge cost and if it dies out of warranty you are screwed and they have a certain lifespan of around 10 years this is ridiculous. IF you could get a heat pump for the cost of an oil boiler then I'd say everyone should have one but until then I wouldn't dream of a heat pump heating system. I know others will completely disagree but each to their own.

Definitely insulation is always best and then use the oil stoves. I guarantee you would not regret it.

Water John

Certainly start with good windows, doors and attic insulation.
The heating system is, in many ways, down to personal choice, cost and future proofing.
Ground source heat pump (GSHP) is a bit more efficient but depends on your site and soil, also dearer.
A2W is generally a plug and play unit. The use of night rate electricity will more than offset the slightly lower efficiency of night operation.
Both are usually matched with UFH. For that you will need to dig out floors at least 300mm.
Certainly, oil system is cheap, in capital terms.
I think, it will be subject to some emissions type penalty, in the not too distant future.

Personnally, I would look at A2W, along with UFH and a timber stove.

top_dog

Water John wrote: »

Ground source heat pump (GSHP) is a bit more efficient but depends on your site and soil, also dearer.

Sorry just had a query on this as I have read this also. Technically I don't understand how the ground source heat pump is more efficient than a2w? In summer if the air temp is higher than ground temp then is the a2w more efficient at this time? Is it only based on the source heat how efficient the pump is? Or is there more to it than that?

Also is a2w very inefficient in sub zero temperatures?

Water John wrote: »

Personnally, I would look at A2W, along with UFH and a timber stove.

Would you just have the timber stove as a space heater and not connected to UFH or for Hot Water? I was going to put one in also. I was just going to leave it for heating room.

Water John

Wouldn't be much into the tech of, why. Liquid to liquid is better thermal transfer, I think.
The best is to use a radiator type exchange located in a nearby stream or lake.

Yes, I would use the stove as a space heater.

Save yourself a tonne of cash bud and forget the money pit of heat pumps. Spend the money on insulation, windows etc and remember your electricity bills will go up especially as it gets colder.

Oil stove definitely the way to go.

top_dog

Deleted User wrote: »

Save yourself a tonne of cash bud and forget the money pit of heat pumps. Spend the money on insulation, windows etc and remember your electricity bills will go up especially as it gets colder.

Oil stove definitely the way to go.

Yea I had looked into getting good insulation in wall but I can't do it cos stone walls have to breathe apparently. Plus the costs of insulation for the walls was by no means cheap and don't want to have dampness and mold problems. I'll be replacing windows and getting good attic insulation and floor insulation.
I have oil at present and it is costing me a fortune.
So at the moment I would be thinking of ground source heat pump with UFH. Also maybe get solar PV panels. Haven't looked at PV panels so don't know the cost. I've heard they coming down in costs though.