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Head fried. Just had someone say use oil not ashp


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Ask him if there's a £7,500 grant to fit the oil burner. Oil burners definitely best to have serviced - I don't bother with my heat pump just as I don't have my fridge serviced.

Running costs may be similar EXCEPT when running off-peak, running off batteries, running with PV and the sun shining.

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1 minute ago, Originaltwist said:

Running costs may be similar EXCEPT when running off-peak, running off batteries, running with PV and the sun shining.

To be fair, adding the cost of PVs and batteries to the ASHP would make it expensive to have installed though, even with the £7500 grant.

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1 hour ago, CalvinHobbes said:

So ventilation guy said loads think ashp are sh*t , expensive to run and cost a fortune to service. He said get a wee oil burner for a fraction of cost. 

In a passivhaus or anything remotely close, absolutely rubbish.

 

Fan coils - flow temp 35. CoP at -2 around 3.5, CoP at 10 deg OAT 5.

 

UFH flow temp 30 or below CoP at -2 around 3.7, CoP at 10 deg OAT 5.7. even if you did all DHW at peak rates, you still cheaper.

 

You can heat off peak with UFH, I currently pay about 13p per kWh.

 

There is almost no servicing to do, look and clean radiator if required. An hour tops. UVC you would do anyway. No more than a gas boiler, possibly less.

 

How the heck are you going to control an oil boiler, and manage heat losses into houses? with virtually no load. You would have to install a thermal store, heat to 70/80 degs for DHW then let the temp down for heating - not in the spirit of Passivhaus.

 

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2 hours ago, CalvinHobbes said:

So ventilation guy said loads think ashp are sh*t , expensive to run and cost a fortune to service. He said get a wee oil burner for a fraction of cost. 

What spec is yours home? 

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I didn't put in any central heating in our passive house. None. These are the reasons.

 

1. Believed the evangelical true believers that seems to think energy is like magic. 

2. Stubbornness driven by a desire to outsmart everyone else.

3. Complete confusion with the range of options. 

4. The outrageous prices charges for ASHPs by plumbers who can't count their own fingers. 

5. Option to fit an A2A was always there. 

 

We use a single resistance heater now . It works fine the rooms are all comfortable but it's dear to run. About €700/year I think. I put extra infrared heaters in the bathroom for comfort. 

 

I had expected it to be cheaper but we can't bank enough heat overnight on a TOU tariff. Also electricity is after triplling in price since 2019. 

 

Time over again I would .....

 

Fit UFH with a willis heater and the option of an ASHP like @TerryE with electric UFH in bathrooms too. 

 

Or install an A2A from the start with electric UFH in the bathrooms. 

 

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I was planning to install ASHP on my Barn conversion in rural Northumberland. (250 sqm) I put in lots of PIR  insulation, and have a South facing gable end which is all glass.  Underfloor heating downstairs, no heating upstairs. Its certainly not passive house standard, but I put a bit of effort in taping gaps and joints etc.  I sought advice all over and did loads of real world research. I eventually came to the same conclusion. I bought a small cheap oil boiler and have no regrets. I spaced the UFH pipes so I could always retrofit ASHP if I have to. I have found the oil boiler cheap to install, cheap to run, and more than efficient for heating.- I have some big double height rooms and its always warm. My oil costs are just a few hundred pounds a year, and often I dont need the boiler on much. Also the floor heats up really quickly, despite what many say, it is almost as quick as a radiator to heat up. (I have a 50mm thick liquid screed over the pipework). We dont need to heat upstairs.

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6 minutes ago, simon45089 said:

I was planning to install ASHP on my Barn conversion in rural Northumberland. (250 sqm) I put in lots of PIR  insulation, and have a South facing gable end which is all glass.  Underfloor heating downstairs, no heating upstairs. Its certainly not passive house standard, but I put a bit of effort in taping gaps and joints etc.  I sought advice all over and did loads of real world research. I eventually came to the same conclusion. I bought a small cheap oil boiler and have no regrets. I spaced the UFH pipes so I could always retrofit ASHP if I have to. I have found the oil boiler cheap to install, cheap to run, and more than efficient for heating.- I have some big double height rooms and its always warm. My oil costs are just a few hundred pounds a year, and often I dont need the boiler on much. Also the floor heats up really quickly, despite what many say, it is almost as quick as a radiator to heat up. (I have a 50mm thick liquid screed over the pipework). We dont need to heat upstairs.

Careful or you’ll have the net zero stasi after you!!

 

Think what this shows more than anything is the heat source isn’t really that important from a cost point of view certainly. 
 

What is extremely important is insulation and air tightness. 

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To be fair there would still be very limited access to quality installers of heat pumps in NI. Oil would be widespread here with a multitude of options for installing and servicing.

The price of oil is low now but it fluctuates yearly. Electricity prices have been fairly consistent until this past 2 years.

Have you got proper as built heat/dhw  demand calculation done yet??

You could always install oil now but with pipes/electric connections already installed so in the future if you wanted to install a heat pump it would be a much easier option.

 

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25 minutes ago, nod said:

Oil definitely cheaper to run

and many are 97% efficient But no longer an option on a new build 

But most installed will be much lower than that. Gas up to 110% but most installed are probably nearer 80%.

 

Had my gas boiler running at 110% efficiency measured by heat meter.  Now got an ASHP and spending around £40 to 60 less in winter per month (electric and gas rates corrected). Only bit with an ASHP that isn't that good is she heating when it's cold outside.  Other than that cheaper especially so if you have solar.

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1 hour ago, nod said:

no longer an option on a new build 

Is that correct? AIUI it is an option until a house is built to the new 2025 Building Regulations.

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We were told by three different sap assessors that the sap would be so loaded that it would be unlikely that we would get planning So we gave up on an oil boiler 

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3 hours ago, Declan52 said:

To be fair there would still be very limited access to quality installers of heat pumps in NI. Oil would be widespread here with a multitude of options for installing and servicing.

The price of oil is low now but it fluctuates yearly. Electricity prices have been fairly consistent until this past 2 years.

Have you got proper as built heat/dhw  demand calculation done yet??

You could always install oil now but with pipes/electric connections already installed so in the future if you wanted to install a heat pump it would be a much easier option.

 

 

 

I'd advocate this approach but just with a cheap willis heater to start. Give it 3 years and the house will really have settled down and you'll have good data to make an informed decision.

 

 

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3 hours ago, Iceverge said:

 

 

I'd advocate this approach but just with a cheap willis heater to start. Give it 3 years and the house will really have settled down and you'll have good data to make an informed decision.

 

 

And if you have an insulated raft you can chunk / bulk heat with the slab as a ‘thermal store’, during off-peak times, to minimise the 1:1 costs somewhat.

Maybe better to have 2 Willis for boosting from these sometimes shorter windows. Also good as a failsafe. 

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On 29/03/2024 at 13:04, Originaltwist said:

Mmmm  Yes oil is looking quite good at the mo.

I've just updated the comparison chart for the next cap etc.

 

Energy March 2024.png

 

What would Electric (eg Fan heaters) with a a battery to time shift look like?

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22 hours ago, nod said:

We were told by three different sap assessors that the sap would be so loaded that it would be unlikely that we would get planning So we gave up on an oil boiler 

 

Do we see large housing estates with heat pumps yet?

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1 hour ago, Temp said:

 

Do we see large housing estates with heat pumps yet?

Have down here on the North Coast.

About 12 years ago a load of houses where built in St. Agnes, most have ASHPs.

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4 hours ago, Temp said:

 

Do we see large housing estates with heat pumps yet?

Noop

Most are gas Just one or two estates have HPs

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5 hours ago, Temp said:

 

What would Electric (eg Fan heaters) with a a battery to time shift look like?

 

An "AA" battery would probably not hold enough juice xD

 

Seriously though you're buying a battery either way.  A "heat" battery in the form of concrete/UVC or an " electric" battery . 

 

Concrete stores about 0.5kWh/m3/K so if you have 10m3 in your floor and heat it 5 degrees you hold about 25kWh for the cost of concrete about £1250 so £50/kWh of storage. 

 

Batteries by comparison are about £600/kWh at the moment. 

 

 

 

 

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