Domestic air source and cold callers

[willie.macleod]

Based on current usage with no increase in demand it would power Great Britain for 3 minutes and 30 seconds. What is the point? We can go 2 weeks with virtually no wind in Winter and solar is way down.

It'll never have to power the whole grid though. I suspect it will be used entirely for grid smoothing and even if you get no wind in winter for two weeks we certainly get plenty of wind here and that battery can be storing power generated anywhere on the grid at times of low demand and releasing at peak demand to help smooth peaks.

 

[fizzy]

It'll never have to power the whole grid though. I suspect it will be used entirely for grid smoothing and even if you get no wind in winter for two weeks we certainly get plenty of wind here and that battery can be storing power generated anywhere on the grid at times of low demand and releasing at peak demand to help smooth peaks.

An area of high pressure can sit over the whole of Northern Europe in Winter for quite some time. Those cold bright frosty days. It happened last Winter and happens most years. Britain can be down as low as 2 to 3% wind power.
How many of these expensive white elephants do we need for "smoothing" anyway?
£750 million is a heck of a lot just to smooth our leccy

 

[Farside]

If we install a water borehole, can the same hole be used for some sort of heating/cooling system? Might be a way to get better value from the same project..?

I've given that some serious thought, as my gaff had a borehole put in by the previous owners, in the 1940s (old country creamery building). I'm on mains water, so the borehole is superfluous to my needs. From what I could gather, one borehole is insufficient, you need a second one to put the colder water back down into, and they need to be seperated by a reasonable distance. As it 'appens, I also have a disused well that's been capped over, about 30m away from the borehole, so I think I might be in with a chance of making it work.
Wanna buy a borehole? Buyer collects.

 

[Morrisman]

Aren't the f**kwits put on earth by God to give us pleasure. Best to bait them into believing that you are interested and get excited at the prospect of an easy sale. When they are just about to peak, tell them to bugger off. Next month they will be selling something different.

Like the door knocking guy with the Irish accent, who told me that any double glazing over 8 years old had to be replaced with triple glazing, by law...... He wasn't amused when I laughed in his face.

Mind you, at 63 I'm the youngest resident in my street, so I'm sure his social profiling training must have convinced him we are all impressionable old f***wits in our area.....

I should have asked him for a quote, now my addled old brain thinks of it.

 

[Morrisman]

Heat people not places. I don't think any of these cold-calling installers have any idea about building physics. I've done a successful heat pump installation based around low-temperature underfloor background heat, with radiant panels for smaller specific areas where sedentary activities would take place. People don't overheat in the active bits or freeze in the stationary ones. The central heating concept is a big problem to my mind and a massive efficiency issue. q

How about thermal body warmer vests, powered by induction coils in every room? Heat the person, not the room?

Mate of mine has an electric heated waistcoat for cold days riding his bike, reckons it is the best thing since sliced bread, powered off a small battery pack in the pocket.

 

[Greeves246]

How about thermal body warmer vests, powered by induction coils in every room? Heat the person, not the room?

Mate of mine has an electric heated waistcoat for cold days riding his bike, reckons it is the best thing since sliced bread, powered off a small battery pack in the pocket.

I used to put an old newspaper inside a Belstaff back in the 60s for insulation but I never thought about using sliced bread.

 

[waddycall]

So when the temperature is around zero, it's useless, no?

No, just less efficient. Ground source heat pumps have their efficiency (COP) measured with an inlet from the ground at 0C and return to the ground at -3C.

 

[brewdexta]

There will be very little difference in the design of a heat pump underfloor heating system and a boiler underfloor heating system as the limitations are the maximum temperature that the pipe will accept and the screed / floor covering maximum permissible temp. The upper limit for the PEX pipe is about 50 C so ideally suited for a heat pump flow which is probably about 45 C without any temperature reduction. When using a gas boiler as the heat source, the maximum flow temperature is limited at the underfloor heating manifold by either local mixing valves or direct boiler temperature control so that the maximum pipe temperature is not exceeded. The density of the pipes would be to suit the area heat loss and wouldn't vary between either source.

Max temp of Pex is 200f or about 96c. The boiler we originally used mixed down to a max of 55c and the return temo safety relay was set to 60c. It was an early boiler designed for UFH with mixing valves built in.

 

[Mikes]

Max temp of Pex is 200f or about 96c. The boiler we originally used mixed down to a max of 55c and the return temo safety relay was set to 60c. It was an early boiler designed for UFH with mixing valves built in.

For years we always fitted a high temperature shut off valve as well as the 3-port mixing valve just in case the mixing valve failed open to the boiler circuit. Most manifolds don't even have the mixing valve now when supplied direct from a condensing boiler set to 50 C flow. Now no one wants to fit the additional valve as they all think no one will ever turn a boiler up! At least with a heat pump you know it isn't ever going to get that hot.

 

[Gazz292]

wait, so i can't fit a 3Kw solar PV array to my west / east facing roof and be able to weld and run the compressor at midnight for free, damn

I am planning on fitting a solar PV array one day, got a small roof that's south facing, and i'd like to get rid of the conservatory and replace that with an extension, so i may just about have room for a 4Kw PV array,

But i'm keeping the gas combi boiler for heating, i might fit electronic thermostatic rad valves to make it into a room by room zoned system tho, got concrete floors, so not sure how well that'd work with an 'underfloor' heating system,


I always wonder why they don't have a combined electric and hot water solar panel,
Solar PV panels reduce their output when they are hot, so why not have a pipe snaking on the back of them and pump coolant through it, absorb the heat from the panels and lower their temps so you get more electric output (maybe) and use that heated coolant to heat a thermal store or something.

 

[minimutly]

The residents saved on average 40% on their previous bills

Well I suppose that's an achievement in itself. Doesn't help though, without knowing what they were spending before, and on what.

 

[fizzy]

wait, so i can't fit a 3Kw solar PV array to my west / east facing roof and be able to weld and run the compressor at midnight for free, damn

I am planning on fitting a solar PV array one day, got a small roof that's south facing, and i'd like to get rid of the conservatory and replace that with an extension, so i may just about have room for a 4Kw PV array,

But i'm keeping the gas combi boiler for heating, i might fit electronic thermostatic rad valves to make it into a room by room zoned system tho, got concrete floors, so not sure how well that'd work with an 'underfloor' heating system,


I always wonder why they don't have a combined electric and hot water solar panel,
Solar PV panels reduce their output when they are hot, so why not have a pipe snaking on the back of them and pump coolant through it, absorb the heat from the panels and lower their temps so you get more electric output (maybe) and use that heated coolant to heat a thermal store or something.

They do exist - quite expensive and prone to problems.

 

[minimutly]

They do exist - quite expensive and prone to problems.

A little pointless just to pick up 2 or 3 percentage efficiency points...
best way is to use an immersion heater and controller so when the sun shines you get free hot water. Oh no, wait, lady next door had hers ripped out by the ASH "engineers", then to cap it all the solar panel guys pinched the old copper cylinder, I had to laugh...

 

[AdW]

Whats the depth of a heat source borehole out of interest?

That depends on the type of system that you want to install and the ground conditions.

An abstraction well for an open system needs to get comfortably into the aquifer and for a domestic well, 10-20 m below the depth at which the pump will be set is common. Perhaps less in good productive rock. The level of the pump will depend on the standing water level, the pumping rate required and the drawdown of the water surface when pumping. If recharge from the aquifer is slow, you can increase yield by drilling deeper (giving you more storage capacity in the well itself) and a greater surface area for recharge, but you need to be careful not to overshoot the aquifer into unproductive ground or into poor quality groundwater.

Groundwater in your well may be resting 25' down, but that might not represent the depth of mobile groundwater in the ground - it could be coming in from fractures or more permeable strata deeper in the well and just rising to rest at that level. A quick look at the expected geology would inform on the likelihood of that. Feel free to DM me your location.

Closed system boreholes may be shallower or deeper! That will depend on the number of linear meters of thermal loop required, the space available and the nature of the ground/groundwater regime. My experience of drilling contractors installing thermal loops is that they will only commit to install XXm total, this is to cover themselves in the event that a loop gets hung up in the hole and can't be persuaded further in or recovered - you can end up with more but shallower loops than intended. 100m deep holes are not uncommon.

 

[Kayos]

Well I suppose that's an achievement in itself. Doesn't help though, without knowing what they were spending before, and on what.

Electricity, it doesn't matter if you spend £2 or £200 a week, 40% is 40% and a significant saving

 

[Kayos]

That depends on the type of system that you want to install and the ground conditions.

An abstraction well for an open system needs to get comfortably into the aquifer and for a domestic well, 10-20 m below the depth at which the pump will be set is common. Perhaps less in good productive rock. The level of the pump will depend on the standing water level, the pumping rate required and the drawdown of the water surface when pumping. If recharge from the aquifer is slow, you can increase yield by drilling deeper (giving you more storage capacity in the well itself) and a greater surface area for recharge, but you need to be careful not to overshoot the aquifer into unproductive ground or into poor quality groundwater.

Groundwater in your well may be resting 25' down, but that might not represent the depth of mobile groundwater in the ground - it could be coming in from fractures or more permeable strata deeper in the well and just rising to rest at that level. A quick look at the expected geology would inform on the likelihood of that. Feel free to DM me your location.

Closed system boreholes may be shallower or deeper! That will depend on the number of linear meters of thermal loop required, the space available and the nature of the ground/groundwater regime. My experience of drilling contractors installing thermal loops is that they will only commit to install XXm total, this is to cover themselves in the event that a loop gets hung up in the hole and can't be persuaded further in or recovered - you can end up with more but shallower loops than intended. 100m deep holes are not uncommon.

Deepest we did was 300m, referred to as medium depth

We only pay drillers for completed loops, if it's 100m short they will be £4k down

More shallower boreholes doesn't always work as the pressure drop on the system becomes too high, the ground side pump can only consume 3% of the units total power so is limited in size

 

[minimutly]

Electricity, it doesn't matter if you spend £2 or £200 a week, 40% is 40% and a significant saving

Damn you can be a stubborn so and so sometimes.
It does matter, since the whole point of the post was to highlight these cold callers telling people they would be saving money on oil heating. But since you don't know, that's that. No one is doubting you're savings, but, oh I give up...
Actually I will say that 40% of £2 is actually, buggerall....

 

[Kayos]

Damn you can be a stubborn so and so sometimes.
It does matter, since the whole point of the post was to highlight these cold callers telling people they would be saving money on oil heating. But since you don't know, that's that. No one is doubting you're savings, but, oh I give up...
Actually I will say that 40% of £2 is actually, buggerall....

I'm just tired of the drivel posted about heat pumps

Sign an NDA and I will share the full M&V report for one of my projects

There is a reason I can't post specifics, but if you sign the NDA, then neither can you

 

[not done it yet]

Fizzy,

Dinorwig @ 9.1GWh is 4 times the capacity of this battery? (no ‘/‘ in GWh, btw - no such unit as GW/h)

The single advantage of a battery is the response time - Dinorwig takes about 20s if the turbines are already spinning (probably a minute, if not). Dinorwig can supply 1728MW - nearly half a GW than this battery (without extra upgrade to the grid connection)

Ffestiniog pumped hydro can add another 360MW with a capacity of nearly 1.5GWh. Both those installations will be working long after the battery has been changed a few times, Inexpect,

Even so, this battery is yet another aid to avoid power outages, balance the grid and act as an energy store. Another piece of the national grid supply.

It could never supply enough power to run the whole grid - even for one second, so the 3 1/2 minute ‘analogy’ is a joke. What Scenario can you foresee where all of the UK power would need to be replaced within a few seconds? We now have nuclear plants as base load as well as fossil fuel generation as dispatchable output. Only the renewables are not quite as predictable - but are quite well forecast most of the time. Then there are umpteen HVDC International connectors.

So what is your problem? I don’t see it, the National grid don’t see it. Only you and a few others cry about it.

 

[minimutly]

I'm just tired of the drivel posted about heat pumps

Sign an NDA and I will share the full M&V report for one of my projects

There is a reason I can't post specifics, but if you sign the NDA, then neither can you

Thanks. As posted above I have no reason to doubt your claimed savings, but I would dispute any claims that a single dwelling domestic system will outperform (on running cost terms) an existing oil system. Until someone can post these numbers I remain sceptic.
Thanks.