Heat Pumps and 10mm Microbore Piping

[Odd-no-more]

Johnson and Stanley are still in business in Northampton and have produced thousands of units over the years and would be able to supply a replacement unit compete I’m sure

They don't do warm air any more it can't get anywhere near the minimum efficiency, they provide a heatexchanger and fan that links to a combi boiler, if you need one don't use their combi, it's

 

[acropolis22]

I think when people already have a system the cost implications are a governing factor , also the instant heat factor can be beneficial,also some people prefer just having the registers rather than the radiators taking up wall space

Agree. All true, but it's not for me.

 

[Tykatem]

Yesterday one customer contacted me to say since fitting the cost has risen to around £10 per day this time of year, and this augmented by a wood burner, from oil costs of around £4.50 per day.

It's all about the insulation!
We have a 2019 All electric 3 Bedroomed det bungalow on the east coast with air source heat pump and underfloor heating throughout. Since the beginning of Nov last year till now our electric bill averages £5.25 per day.

Pete

 

[acropolis22]

It's all about the insulation!
We have a 2019 All electric 3 Bedroomed det bungalow on the east coast with air source heat pump and underfloor heating throughout. Since the beginning of Nov last year till now our electric bill averages £5.25 per day.

Pete

And with the recent price increases, I wonder what it would cost to heat with a gas boiler?

 

[Richard n Ann]

It's all about the insulation!
We have a 2019 All electric 3 Bedroomed det bungalow on the east coast with air source heat pump and underfloor heating throughout. Since the beginning of Nov last year till now our electric bill averages £5.25 per day.

Pete

Our smart meter screen is saying we use about £4 a day for gas & electric. Don't know if the correct rate is programed into it or what. Only started looking at it since our tariff changed on the 25th

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[gpat]

Still don’t know why increased pipe work necessary you are transferring less energy to the radiators ! Yes an increase in radiator surface area will possibly be needed it all relies on mean water temperature differential.

That's because , if the water temperature is lower you basically have to shift more water around the system in order to transfer the same amount of heat (BTUs) into the room. Systems with micro bore are already often at the limit (they don't use it anymore do they for that reason).

 

[Plumb]

That's because , if the water temperature is lower you basically have to shift more water around the system in order to transfer the same amount of heat (BTUs) into the room. Systems with micro bore are already often at the limit (they don't use it anymore do they for that reason).

Extra flow rate doesn’t equal more British thermal units

 

[Plumb]

They don't do warm air any more it can't get anywhere near the minimum efficiency, they provide a heatexchanger and fan that links to a combi boiler, if you need one don't use their combi, it's

I stand corrected but they do on Johnson and Stanley website supply a warmcair unit quoted to be 98% efficient

 

[Plumb]

It's all about the insulation!
We have a 2019 All electric 3 Bedroomed det bungalow on the east coast with air source heat pump and underfloor heating throughout. Since the beginning of Nov last year till now our electric bill averages £5.25 per day.

Pete

Exactly right less demand equals less consumption

 

[Ejaydee]

Since the beginning of Nov last year till now our electric bill averages £5.25 per day.

And ours would have been less than that (also a 3 bed detached bungalow, all electric and ASHP, plus an EV, but in Cornwall), especially before the recent increase in cost (we are out of contract and put on variable! ). Before the recent energy price increase, we had a DD of £100 pm, and we were able to stay easily within that figure, usually with a rebate given back to us during the summer months.

As we only received our smart meter a couple of months ago, I would have to go through paperwork to check what our average daily/weekly cost was pre December, but the cost for the last week using the meter, even with the massive increase in energy costs, was £39.57 (£5.65 per day average) and that included charging the EV on one day. The week before it was £40.75. Since the smart meter went in just before Christmas, the average cost of electric per week has has hovered around £40 mark, with one weekly cost of just over £50 (£7.14 average) when the tumble dryer was in use in wet weather on a couple of days and when cooking large roast dinners over Christmas/New Year period.

I fully charged the car again today (45% up to 100%) and the cost of all our electricity consumption will naturally be greater than average. So far it is £5.75 today, and that includes the washing machine being on for a full load and the ASHP heating up the house and water early this morning. As we have a "heat store" full of hot water and the house is already warm, I do not think the cost will be much more than another £1 by midnight. However, I must point out, we do have PVs on the roof (3.89Kw) and it has been nice and sunny today (hence me deciding to charge the car), and so naturally we have made a point of turning on the heavy demand items (car, washing machine, dishwasher etc) while the sun is shining, but not all at the same time, to get the benefit of the PV output.

Having now lived with air source heat pumps for 9 or 10 years, I do not recognise all the negative aspects that some others highlight, IMHO, they are highly efficient (far higher efficiency than a gas or oil boiler) and they do the job as expected in the setup that we have here.

However, as I and other people have said in other threads on the subject, they definitely are not suitable in every situation and for every property though, particularly older or badly insulated properties.

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[gus-lopez]

Air source heat pump? = originally used as pool heaters.
Air to air heat pump? = posh name for a reverse cycle air con unit.

 

[Richard n Ann]

Our smart meter screen is saying we use about £4 a day for gas & electric. Don't know if the correct rate is programed into it or what. Only started looking at it since our tariff changed on the 25th

Just checked the price per kwh in the smart meter screen and it's correct

 

[Odd-no-more]

I stand corrected but they do on Johnson and Stanley website supply a warmcair unit quoted to be 98% efficient

Yes that's what I was talking about

 

[Plumb]

Yes that's what I was talking about

Ok I thought that unit wasn’t a water to air heat exchanger ?

 

[almichie]

Hi

Has anyone had their gas/oil central heating upgraded to an Electric Heat Pump and had any issues?

Ive heard that the flow and the fact that new heat pump systems are pressurised can cause flow issues along with leaks.

I work in this industry, probably easier if you call me. Pm for a number and I will happily chat through it all.
but the up shot it - unless you have underfloor heating don’t bother. The surface area of the radiators sized for a boiler will not output the same amount of heat, in fact you will feel cold. Not only that system flow rate design is very different And you will consume a huge amount more energy.

unless you are on electric point of use heaters it is a waste of time. New installations with a system designed for a heat pump

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[MisterB]

The Ex-Gasman

I would not have a have an air to water heatpump but I am getting an air to air heatpump, just one at the moment to see how well it does, I know they work well but can be noisy. If it works we will only use the heating in the morning and late evening and use the heatpump to keep the main room warm in the day and if it's good I will add more units to heat the whole bungalow. If it doesn't work I will at least have air-conditioning in the main room for the summer.

we have heated our kitchen and conservatory using a 2.5kw Fujitsu inverter (air to air heat pump/air con) from April last year, its around 34 sqm in total - its worked pretty good to be honest. there is the odd evening when we have felt 'cooler', with the inverter set to 21 degrees, so we turn it a bit higher and its 'ok'. obv with it being a conservatory its a bigger heat loss than it would be for a 'normal' room.

running cost is not scary and its pretty efficient in heating the room - i try to keep an eye on the smart meter monitor.

i am tempted to add another within the house, but have recently fitted Quantum storage heaters throughout (other than the conservatory/kitchen) which also seem to be working well. (we are all electric, no gas, 1950's detached property in a rural area) - we do have 4kw of solar which i think really helps keep the operating cost of the inverter lower than it would be, an advantage being of course that in the summer, the solar will probably cover the cost of running it as air con.

 

[JBob]

Not quite sure of the relevance of pipework sizing ! After all the heat pump is only another form of heating energy medium no difference gas ,oil , coal electric all the same as far as system heat requirements

They run much cooler, with small bore pipes the heat is lost before it reaches the rads,

 

[gpat]

Extra flow rate doesn’t equal more British thermal units

Yes it does. Surely

 

[EuroTrotters]

Thanks everyone for the replies.

I have been an RAC Engineer for 35 years. Just installing a new office system, see here

https://www.motorhomefun.co.uk/forum/threads/gas-prices…………wowzer.256910/#post-4881408

I did install a MultiFuel Stove with back boiler that heated my whole house back in 1985, gravity fed tank with 28mm pipe, pumped rads.

But I know very little about these heat pump systems performance other than the science.

So, from what you all suggest, it will be a no then.

Thank you all so much

 

[EuroTrotters]

Heat pumps have been around donkeys years and never very efficient and consequently never caught on

First one I fitted had a COP of 2, 35 years ago. Was on R22

The ones I have fitted are SCOP 5.3 and R32

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[EuroTrotters]

I work in this industry, probably easier if you call me. Pm for a number and I will happily chat through it all.
but the up shot it - unless you have underfloor heating don’t bother. The surface area of the radiators sized for a boiler will not output the same amount of heat, in fact you will feel cold. Not only that system flow rate design is very different And you will consume a huge amount more energy.

unless you are on electric point of use heaters it is a waste of time. New installations with a system designed for a heat pump

PM SENT

 

[MisterB]

I intend fitting a heat pump in the future, I have already installed underfloor heating pipework in the kitchen and conservatory, the reasons I havent done it already are because my inverter worked really well and air to air is supposed to be more efficient than air to water and the ridiculous cost I have been quoted!

I have also been looking at ways to add extra insulation, which along with reducing drafts, is the real key in my opinion.

I would also like to fit additional solar to power batteries but the price of batteries needs to come down quite a lot to actually make it cost effective.

 

[Dutch 68]

And no doubt a sharp intake of breath before they worked out the cost of the extra plumbing.

All good in a highly efficient passive house, installing a heat pump as only source of heating in a older house is not a wise move…….

 

[almichie]

I intend fitting a heat pump in the future, I have already installed underfloor heating pipework in the kitchen and conservatory, the reasons I havent done it already are because my inverter worked really well and air to air is supposed to be more efficient than air to water and the ridiculous cost I have been quoted!

They are expensive, and they’re expensive to run and maintain in the main.

A refrigerant circuit will always be more efficient than a point of use electric, oil or even gas burner but the electric unit price vs gas will mean it is more expensive to run.

 

[MisterB]

They are expensive, and they’re expensive to run and maintain in the main.

A refrigerant circuit will always be more efficient than a point of use electric, oil or even gas burner but the electric unit price vs gas will mean it is more expensive to run.

We don't have any mains gas, we were quoted 25k to have gas installed .... hence the 'intent' to investigate electricity storage, but insulation is prob more cost effective than any heating solution.

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[Plumb]

They run much cooler, with small bore pipes the heat is lost before it reaches the rads,

Sorry that’s not true a pipe with a larger cross sectional area will dissipate more heat than a smaller cross sectional pipe ! That’s a fact .

 

[Plumb]

Yes it does. Surely

No sorry a British thermal unit is a unit of heat

 

[MisterB]

re heat pump pipe sizes - lower temp of water needs a high flow (mass) of water, which is why larger pipe sizes than microbore are required - an increased pump size wouldnt really be a practical solution.
As the heating is ran at a lower temperature, then transferring that heat to a well insulated thermal mass (pipes in concrete floors) is an effective method of heating areas - one method not seen often, is using the internal walls as the thermal mass - in theory there is no reason why internal walls (not exterior walls) shouldnt be just as effective as underfloor heating.

 

[gpat]

No sorry a British thermal unit is a unit of heat

And doesn't hot water carry units of heat. The hotter the water the more units of heat. The greater the volume (flow) the greater the units of heat entering the radiator.

 

[gpat]

Sorry that’s not true a pipe with a larger cross sectional area will dissipate more heat than a smaller cross sectional pipe ! That’s a fact .

Its not a fact. You are kind of correct though. Its the surface area that is important not the cross sectional area. Thats why radiators are so effective

So a narrow pipe has a greater surface are (relatively) than a big pipe.

You are arguing with a scientist and not a plumber

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