Heat Pumps - post here.

KCross

Probably the wrong thread looking for window advice. New thread?!

KCross

KCross wrote: »

Probably the wrong thread looking for window advice. New thread?!

Depends as windows are to do with efficiency. But yeah probably not the best discussion for heat pump thread.

la ultima guagua

Deleted User wrote: »

....your windows would have to open in instead of out ! .....

So they should. (lets stop killing window cleaners)
This topic came up a couple of years ago. Amazing that many are against the idea !

Would lots of Glass effect efficiency for a heat pump ?

KCross

Deleted User wrote: »

Would lots of Glass effect efficiency for a heat pump ?

Not really. Its all down to u-values and air tightness, not the amount of glass per-se.

Put in s*it windows and the HP will just have to run for longer to make up for the heat loss.

Big Dec

Speaking of glass, I have the situation (possibly mentioned in some of the forums previously) where I have loads of glass in my sunroom which also has a vaulted ceiling.
I see that the room cools down faster than the UFH can provide heat.
Sun keeps room nice & toasty when it is there, but once the temperature drops below the UFH setpoint it takes a while to react. No point in setting the flow temperature higher just to get one room hotter faster.
I was also thinking of getting a good electric heater to give the room a little "boost" whenever this happens.
I'm not saying that the room is cold (~20C), just not as comfortable as one would like to be sitting watching TV.

KCross

Big Dec wrote: »

Speaking of glass, I have the situation (possibly mentioned in some of the forums previously) where I have loads of glass in my sunroom which also has a vaulted ceiling.
I see that the room cools down faster than the UFH can provide heat.
Sun keeps room nice & toasty when it is there, but once the temperature drops below the UFH setpoint it takes a while to react. No point in setting the flow temperature higher just to get one room hotter faster.
I was also thinking of getting a good electric heater to give the room a little "boost" whenever this happens.
I'm not saying that the room is cold (~20C), just not as comfortable as one would like to be sitting watching TV.

Maybe its different for you but I can adjust the flow to most rooms individually at the manifold. Maybe your sunroom has a flow adjustment of its own and it is simply set back too far?

Big Dec

All rooms are supplied via separate manifolds.
There is no buffer tank, so bathrooms & halls are always on as a type of buffer.
What I meant to state, but likely didn't do very well, is that I have a fixed flow temperature & in the past I was experimenting with increasing this gradually, however this meant that the "buffer" areas were being heated unnecessarily.

KCross, are you referring to opening up the flow rate controllers fully for that room?
I'm also just thinking now that the couch & armchairs are reducing the area available for heat to radiate into the room.
There is also laminate flooring here too which further reduces the rate of transmission.

KCross

Big Dec wrote: »

All rooms are supplied via separate manifolds.
There is no buffer tank, so bathrooms & halls are always on as a type of buffer.
What I meant to state, but likely didn't do very well, is that I have a fixed flow temperature & in the past I was experimenting with increasing this gradually, however this meant that the "buffer" areas were being heated unnecessarily.

KCross, are you referring to opening up the flow rate controllers fully for that room?
I'm also just thinking now that the couch & armchairs are reducing the area available for heat to radiate into the room.
There is also laminate flooring here too which further reduces the rate of transmission.

I don't know your install obviously but for me I have flow rates I can adjust at the top of each output in the manifold and each one of those is for a specific run of the UFH so I can adjust each room individually.

On your manifold do you have adjustments on each output and do you know which output is for the sunroom? Can you open that up to increase the supply to the sunroom.

I wouldn't mess with the flow temperatures in the HP. As you said, that just drives every room up.
I don't think furniture will effect it much but the laminate might. You are also supposed to use specific underlay that lets the heat through.

Water John

Yeah Cross, standard flow rate would be 1.5l/min. If you have the option increase that.
The flow meters themselves impede flow rate a fair bit. You could remove the one or two involved and tap with blanks. The thermostat for the room will still turn off the flow with the actuator, if it gets too warm.

Glass u value has much improved but we would have always suggested, spacing of 100mm in sun rooms as opposed to standard 150mm. Even 200mm enough upstairs.

Big Dec

In my previous post, I was referring to the flow rate controllers on the manifolds, so I have indeed opened them fully.

That's a good point regarding the flow meters - I'll have to try that once I switch on the heat pump in the next few weeks.
Any idea of how much a typical meter would impede the flow by?
What would the difference be between fully opened and removed?

For the flooring, I have used the recommended underlay.

Water John

Its a few years, but I remember seeing the figures and they were quite high.
Its only trickle through and anything would significantly impede it.
Once you have a blank, its easily worth a try.

Can't remember that it's called, where the measuring instrument becomes part of the problem.
Guy in Shannon invented a solution to it in the aeronautics industry. Saw the problem at work and designed it over a weekend. Built a business out of it.
Usual tangent rambling, for me.

KCross

Big Dec wrote: »

In my previous post, I was referring to the flow rate controllers on the manifolds, so I have indeed opened them fully.

Opened one for the sunroom or all of them?

If you open all of them it would defeat the purpose, I think. What you need is to provide more supply to the sunroom relative to the other rooms.

If you have done it right it might be just a simple case that the sunroom is leaking too much heat. Start looking at spaces around windows/doors/sockets.

Big Dec

I had fully opened the flow rate controllers for the sunroom only.

I'll play around with it a bit once I have it up and running again.
House is very airtight so flow could be a contributing factor.
I appreciate the feedback on this topic.

caddy16

Is there a heat pump available that can be linked to the heat recovery ventilation system to utilise the warmer air that's extracted?

MENACE2010

caddy16 wrote: »

Is there a heat pump available that can be linked to the heat recovery ventilation system to utilise the warmer air that's extracted?

the heatrecovery already strips the heat out of the stale air to pre-heat the fresh air.. so there is not alot left for the heatpump . there are systems that either have a heatpump in the recovery system or can be hookedup with a pre-heating coil , water or electric to heat the fresh air another step up. But in Ireland it rarely freezes that hard to warrent that investment.

caddy16

After reviewing this thread and carrying out my own research over the last few weeks it seems to me that the cost of geothermal heat pumps must have reduced over the last few years. After calculating our heat & hot water requirements the recommended heat pumps are 6KW geo or 9kw a2w. Approx 10k for the geo and 11k for the a2w both figures including installation but excluding heat source (ufh or rads). If I include ground works for the geo they probably work out the same.

In comparison to oil & solar or PV the capital outlay is not as big as I have been reading about or expected. I know UFH will work out more expensive than rads but again not massively so.

My question is are others who are currently researching for a new build seeing something similar?

I would like to renovate over the next few years and this is something I need to think about also.

Airtightness and insulation and heat recovery and if the house is air tight and insulated enough I wouldn't bother with the expense of heat pumps with the potential for expensive repairs down the line.

The heat recovery setup is very interesting, when the sun shines the warmer air will be distributed to the cooler parts of the house. I want large windows and lots of light. If I convert the attic then most likely the rooms there would be much warmer in Summer so the heat recovery can suck some of this and send it to the cooler parts downstairs, I like the idea of this system the most.

I would most likely go with electric heaters in each room, we don't like mush heat in the bedrooms, 18-19 Deg C max. Electric heaters are dirt cheap and in a well insulated and air tight house running costs should be very low.

If I get the new Nissan Leaf it will have optional V2G system meaning I can charge up on the work electricity or when off shift
charge up on cheap night rate electricity and use some of that when I'm home at peak time. The cost is unknown yet and even though it's called Vehicle To Grid the ESB most likely still will not provide a feed-in-tariff so I could have it installed in such a way that it provides power to the house only.

With the high humidity in Ireland , it's regularly above 60% and frequently 80% and above and a lack of control on humidity then a heat pump setup and under floor heating is out for me, I like to be able to adjust my temps quickly to suit my needs at the time. The heat recovery should in come way take care of this by allowing fresher air to the parts of the house that need it, if not I could look at AC for one or two rooms.

I have an Effel Oil stove in the Kitchen, dining, Conservatory area and is extremely economical, 0.4 L per hr and is plenty warm on min setting. I could install one of these for when it's very cold, because of the unpredictability of our climate it's good to prepared for longer cold spells also.

I am interested in Solar PV, though again, the cost V payback is a bit long with no grants or FIT available and unlikely for many years by the looks of it. Solar water heating is of no interest to me as I do not have the need for 300L of hot water daily and at least you can use the Solar PV for much more, it makes much more sense.

So many options, insulation and air tightness is key.

I'm just thinking out loud so forgive the rambling. I would love to get an idea of the costs involved.

athlone99

My question is are others who are currently researching for a new build seeing something similar?

We are currently awaiting planning permission and I have been getting quotes to put a budget together. For A2W we are averaging around 9k inc VAT and around 12.5/13k for a Geothermal HP inc VAT. The house is 227sqm and I think our decision will come down to what we can afford.

KCross

Deleted User wrote: »

With the high humidity in Ireland , it's regularly above 60% and frequently 80% and above and a lack of control on humidity then a heat pump setup and under floor heating is out for me, I like to be able to adjust my temps quickly to suit my needs at the time.

The heat recovery should in come way take care of this by allowing fresher air to the parts of the house that need it, if not I could look at AC for one or two rooms.

Why do you conflate heat pumps and UFH with controlling humidity? They don't have anything to do with each other, no more than an oil burner does so why use humidity as a reason not to buy a heat pump?

You keep creating "issues" for heat pumps that don't actually exist.

I can agree they are not cheap and potential for breakdown is a worry but oil burners require maintenance and replacing as well. The humidity angle though, just doesn't make any sense.

Some form of Heat recovery ventilation is required in an airtight house regardless of what heating system you have.

Deleted User wrote: »

I have an Effel Oil stove in the Kitchen, dining, Conservatory area and is extremely economical, 0.4 L per hr and is plenty warm on min setting. I could install one of these for when it's very cold, because of the unpredictability of our climate it's good to prepared for longer cold spells also.

This kind of proves my point of you needing to understand heat pumps and UFH a bit more..... they use constant temp... this idea of boosting is how traditional oil fired systems work and isn't required with a heat pump.

You suggest heat pumps are not worth it but at the same time you are suggesting you'll pay out extra for a stove and associated oil to boost heat. Thats just extra hassle, money and another thing to maintain. Will you save anything in the long run?

Even in an airtight house it will still cost money to heat it. Electric heaters will be an inefficient way to do it so I hope you have your figures worked out for both CapEx and OpEx.

Deleted User wrote: »

I am interested in Solar PV, though again, the cost V payback is a bit long with no grants or FIT available and unlikely for many years by the looks of it. Solar water heating is of no interest to me as I do not have the need for 300L of hot water daily and at least you can use the Solar PV for much more, it makes much more sense.

Whats your plan to heat water? Every house needs a water boost every day so you can't rely solely on Solar. Are you going to rely on immersion, which is very inefficient? And I already know you consider electric showers an abomination so whats your hot water plan? Heat pumps heat the water too, very efficiently!

antoinolachtnai

Airtightness and insulation are the most expensive measures. It's just because there is a lot of labour and material involved. This cost is unlikely to fall much with improving technology.

The external insulation is the cheapest way to insulate the walls. This gives you an idea of the cost, though the prices there seem a bit 'light' to me.

http://www.abac.ie/how-much-does-external-home-insulation-cost/

You still need to do the windows and roof, and add the HRV.

This is a good chunk of money. All told, it will work out at the guts of 40k at least, which is a quarter of what it would cost to build a house from scratch. It will be very hard to get a return on it quite honestly unless the price of energy goes up considerably or there is some sort of measure to make it more expensive.

But it depends how deep your planned renovation will be really.

Once you seal up the house, the temperature should be much more stable than it is now. That should (in principle) mean that turning heat on and off in response to changes in weather conditions won't be so necessary.

Individual heaters are a way of doing it, but it really depends on the control. With smart metering, it will become very expensive to run these electric heaters at certain times of day.

The HRV will possibly also result in heat being spread around the house. You won't be able to heat just one room as easily.

Heat pump technology will come down in price somewhat and the expertise will improve. The idea that heat pumps are breaking all over the place is not quite right either. They have pumps and motors for sure, but they often last a long time. And although they break, they don't necessarily need much ongoing maintenance.

An AC is basically an air-to-air heat pump. So you are signing up to much the same thing.

I wonder if your oil stove is really that efficient? It is responsive, certainly, but a lot of heat (at least 15 or 20 percent) probably goes out the chimney. It also has maintenance costs, and certainly needs to be serviced regularly (if only for safety reasons).

There may well be a lot of off-peak electricity on the grid in a few years.

So the cheapest thing in the end may well be to run heat pumps (maybe even air-to-air) and put in whatever amount of insulation is economic.

KCross

athlone99 wrote: »

We are currently awaiting planning permission and I have been getting quotes to put a budget together. For A2W we are averaging around 9k inc VAT and around 12.5/13k for a Geothermal HP inc VAT. The house is 227sqm and I think our decision will come down to what we can afford.

Any idea what the expected running costs are for each system?

If, for instance, it costs €400/yr extra on electricity to run the A2W then the extra money will be repaid in 10yrs.

However, in the 10yrs following that the A2W is likely to require significant maintenance (possible replacement). There is a very good chance the Geo will still be running strong.

I know when building you have a tight budget and its hard to look at the long term running costs but please do look at those figures before deciding.

And more importantly, get some more quotes.... you might have an inflated quote so maybe there isn't really €4k in the difference if you price around and do some more negotiating.

I disagree about the heat pump. Electric heaters for the bedrooms are dirt cheap and won't cost much more to run than a heat pump especially if the house is well insulated and they won't be actually running all day.

Perhaps a storage heater for the sitting room to use off peak energy but, again, if the house is well insulated and air tight then the need to use electric heating all day probably won't require the need for a storage heater.

Oil for the living areas, and yes 0.4L per hour is the rated minimum oil consumption. Maintenance is not a lot what so ever. This is for the 9 Kw stove, a 3-5 Kw stove will be much less and still provide plenty of heat for most sitting rooms.

Solar PV can assist in the running of electric heating , but really a FIT is required for solar unless you can use all the energy, which will be much more in Summer so this is where you need the FIT and then buy the energy back in Winter. The Solar PV is going to cost though.

I was considering wood pellet but the cost of an electric heater would be much cheaper given the cost of the stoves, then who fixes it if it breaks ? I have an energy monitor I can plug into the electric heater to give me an idea of the cost to run per week just for the sitting room which isn't large currently. Block up the chimney to stop the heat getting sucked out which will also greatly cut down on the draught.

First thing I need to do is get an architect , more important to me is space and light. I can spend some money on energy if needs be.

If anyone knows of a good architect pm me please.

KCross

KCross wrote: »

Any idea what the expected running costs are for each system?

If, for instance, it costs €400/yr extra on electricity to run the A2W then the extra money will be repaid in 10yrs.

Who's to say you won't get some very cold winters ? then it will cost you a lot more to run.

KCross

Deleted User wrote: »

Who's to say you won't get some very cold winters ? then it will cost you a lot more to run.

Whats your point?

The colder it gets the more inefficient A2W gets. Geo is less affected because the temp underground is relatively constant.

Again, I don't think you understand HP tech.

KCross

Deleted User wrote: »

I disagree about the heat pump. Electric heaters for the bedrooms are dirt cheap and won't cost much more to run than a heat pump especially if the house is well insulated and they won't be actually running all day.

What exactly do you disagree with?

I know electric heaters are dirt cheap but not cheap to run and very inefficient. You complain a lot about electric showers... an electric heater is no different in that regard.

You didn't answer how you plan to heat hot water?


Everyone has their own requirements and if you want to be flicking electric heaters on/off in each room then go for it. It wouldn't be for me and as already pointed out with smart meters coming in you will be using a lot of electricity at the peak time of the day.... quoting an airtight house doesn't mean you won't have to turn on the heaters when you get home.

No I understand perfectly, it's an expensive system that takes a long time to pay back and you're praying all the time it doesn't break.

caddy16

athlone99 wrote: »

We are currently awaiting planning permission and I have been getting quotes to put a budget together. For A2W we are averaging around 9k inc VAT and around 12.5/13k for a Geothermal HP inc VAT. The house is 227sqm and I think our decision will come down to what we can afford.

My house is a similar size, can I ask what size geothermal heat pump you have been quoted for?

I know insulation & air tightness will have an impact.

KCross

Deleted User wrote: »

No I understand perfectly, it's an expensive system that takes a long time to pay back and you're praying all the time it doesn't break.

Expensive is relative and no heating system pays for itself.

So, if thats the sum of your knowledge then fire away with the electric heaters!

KCross

KCross wrote: »

What exactly do you disagree with?

I know electric heaters are dirt cheap but not cheap to run and very inefficient. You complain a lot about electric showers... an electric heater is no different in that regard.

You didn't answer how you plan to heat hot water?


Everyone has their own requirements and if you want to be flicking electric heaters on/off in each room then go for it. It wouldn't be for me and as already pointed out with smart meters coming in you will be using a lot of electricity at the peak time of the day.... quoting an airtight house doesn't mean you won't have to turn on the heaters when you get home.

Electric heaters are not expensive to run in a very well insulated air tight house. Thermostats and timers do all the flicking, I don't have to do anything. Storage heater can be used in the living area if needs be or oil.

Hot water can be heated by cheap off peak electricity in Summer as now and/or by using the oil stove which currently does not heat water or rads.

No I'm not a fan of electric showers in houses that heat the water by oil, gas or solid fuels, it's a complete waste of energy. Pumped only showers use already heated water or you could install 2 showers one that heats water in Summer and one pumped for the cooler months which is most of the year in Ireland.

I don't get you with smart meters ? I already use most of the house electricity requirements during peak usage. My Partner won't run the dishwasher at night and now runs the washing machine mostly during the day because she has to work so it's not convenient to hang up clothes before she goes to work. Water is heated when necessary on of peak electricity during the warmer months.

The Car consumes by far the most energy which is charged off peak when I work days and peak when I work nights , until I get the new Leaf maybe, which will be charged at work for my commuting needs. V2G if cheap enough will run the house when I'm plugged in using work electricity, that is if I'm still there at that time or the system will allow me to charge on off peak energy and run the house when I'm home.