Future Firewood Demand Optimism?

[openspaceman]

11 hours ago, Baldbloke said:

I’m sure heat pump efficiency has improved vastly over the years, but my experience of them about 18 years ago was not good. A scout building was considered too expensive to heat for its limited use plus a grant was available at the time too. 10 k worth of equipment was installed and ran until the first quarterly bill came in at over £800.00.
The heat pump was removed shortly after that.

This is exactly the situation we decided air circulating pellet stoves were ideal for, a 10kW fast heat up of the air space  which tailed off as horsed of sweaty bodies contributed their 200W to.

 

We imported 25 in about 2000, I still have the demo unit idle in my shed, but take up was not good and the pellet price shot up from£70/tonne.

[openspaceman]

2 hours ago, Puffingbilly413 said:

The insulation point is a good one and certainly is a factor in the winter re money spent on heating.  That said, there have been certain points this summer when I have been glad of the cooler temperature inside an old stone built house.

You too are missing the point like @Big J's guardian reader. As @Woodworks says if the stonework is insulated outside the  insulation can prevent solar gain, thus keeping the inside cooler

[openspaceman]

2 hours ago, Puffingbilly413 said:

Sounds like GSHP might be more efficient?

It's interesting that I seem to hear more problems with ASHP than GSHP but that may be because they tend to be much cheaper to install.

 

My first experience of GSHP was 30 years ago on a big house, offices and garden of a property developer. The pipes were under about an acre of lawn. In deep winter they tried to heat everything, including a pool and stables and this resulted in the soil around the pipes freezing and raising ridges in the lawn. This was entirely a problem of the development company owner not understanding the science and he scrapped the installation rather than accept its limitations and add an alternative for cold weather.

 

I came across a similar thing when my brother converted an old house into 8 flats, he did not take advice and fitted radiators instead of underfloor, he also used the ASHP for domestic hot water whereas a point of use hot water would have been more sensible. Worse still was because 8 flats domestic hot water was stored in a common tank the temperature had to be raised electrically each day to eliminate Legionella bacteria. Had the ASHP only supplied underfloor heating it would have been adequate most of the time. Instead it was ripped out at great expense.

 

The interesting thing about ASHP  is that the air temperature varies  much greater than the soil even only six feet down, so in cold weather the GSHP has less work to do as long as the heat exchange surface under ground is adequate. Both depend on the sun. Oddly a lot of folk seem to believe that GSHP get their heat from the earth's core[1], there is some but it's only about 50mW/m2, the vast bulk is stored up in the surface layers in warmer weather. It strikes me a big pond would be an ideal source as the bottom layer would remain at 4C even as ice thickens over the top.

 

[1] this reserve of heat in hot rocks is  accessed because the hot rocks have been heated for millennia but as the heat is taken out, in Iceland as high pressure steam  or low temperature water from flooded mines, the rocks cool faster than the heat coming in from the core, so the heat is not sustainably mined any more than an aquifer  in a desert region is mined for water.

 

 

[Chalgravesteve]

4 hours ago, Puffingbilly413 said:

I did try to get our loft re-done through one of the grant schemes but when they came round to assess the job, the cost of ripping out the old loft boarding and re-doing it (not that old either) would have fallen on us and we simply couldn't afford to do it at the time so we let it pass.  I think we'll have to revisit the idea though.

Why rip out the old boarding? If you put the new, extra deep insulation onto the existing loft boarding, you are still insulating and retaining any heat existing below that? If you need some loft flooring, put a new suspended loft floor in where you need it?

 

If you rip out all the old stuff, you are then putting new extra deep insulation onto the ceiling boards of the room below. If you put it onto the existing loft floor, there is an insulated layer under your insulated layer and unless there is a bloody great hole where the air can escape to within that layer, then you must be achieving the same thing.

 

 

[Rob_the_Sparky]

2 hours ago, openspaceman said:

The interesting thing about ASHP  is that the air temperature varies  much greater than the soil even only six feet down, so in cold weather the GSHP has less work to do as long as the heat exchange surface under ground is adequate. Both depend on the sun. Oddly a lot of folk seem to believe that GSHP get their heat from the earth's core[1], there is some but it's only about 50mW/m2, the vast bulk is stored up in the surface layers in warmer weather. It strikes me a big pond would be an ideal source as the bottom layer would remain at 4C even as ice thickens over the top.

 

[1] this reserve of heat in hot rocks is  accessed because the hot rocks have been heated for millennia but as the heat is taken out, in Iceland as high pressure steam  or low temperature water from flooded mines, the rocks cool faster than the heat coming in from the core, so the heat is not sustainably mined any more than an aquifer  in a desert region is mined for water.

 

 

I don't know any details but for sure a pond can be used but it might have to be quite large.  One of the University of Surrey's buildings is heated using this technique but the pond is actually quite a sizable lake.  Interesting about the amount of heat from the core.

 

wrt solar hot water:

How do you avoid boiling the tank if not using water fast enough?  If you size the panels to be useful in winter then in summer the power is just going to be far too much. (also going on holiday might be an issue)

As most systems appear to be pumped, how do you prevent it boiling if the pump stops?

 

Both of these have been things stopping me moving beyond thinking about it.

[Billhook]

1 hour ago, Rob_the_Sparky said:

I don't know any details but for sure a pond can be used but it might have to be quite large.  One of the University of Surrey's buildings is heated using this technique but the pond is actually quite a sizable lake.  Interesting about the amount of heat from the core.

 

wrt solar hot water:

How do you avoid boiling the tank if not using water fast enough?  If you size the panels to be useful in winter then in summer the power is just going to be far too much. (also going on holiday might be an issue)

As most systems appear to be pumped, how do you prevent it boiling if the pump stops?

 

Both of these have been things stopping me moving beyond thinking about it.

I thought that people living next to a river found it a better source than the ground, cannot remember where I read it though

[david lawrence]

Village Open air swim pool at Lazonby cumbria

heated by ‘water’ source heat pump type arrangement

rivet Eden didn’t seem that warm to me last time I was in thou

 

 

[Puffingbilly413]

7 hours ago, openspaceman said:

You too are missing the point like @Big J's guardian reader. As @Woodworks says if the stonework is insulated outside the  insulation can prevent solar gain, thus keeping the inside cooler

No I’m not - I agreed with the point. I was just saying I like my house cool inside in the summer.  I believe I acknowledged J’s point about insulation…

[openspaceman]

4 hours ago, Rob_the_Sparky said:

I don't know any details but for sure a pond can be used but it might have to be quite large.  One of the University of Surrey's buildings is heated using this technique but the pond is actually quite a sizable lake.  Interesting about the amount of heat from the core.

 

wrt solar hot water:

How do you avoid boiling the tank if not using water fast enough?  If you size the panels to be useful in winter then in summer the power is just going to be far too much. (also going on holiday might be an issue)

As most systems appear to be pumped, how do you prevent it boiling if the pump stops?

 

Both of these have been things stopping me moving beyond thinking about it.

My second try at replying as lost first in cycberspace. Twenty years ago I did a lot of work in UniS grounds and woodlands and wasn't aware of that. They now have a woodburner at the sports complex. I guess the sizeable lake is also heating a sizeable building. The thing about a natural pond is that the  coupling with groundwater exchanges more heat and as @Billhook says a running river is picking up heat as it travels. Also water is good at absorbing infra red radiation from the sun.

 

I wouldn't worry about solar thermal over heating in this country and even if it did there are ways to deal with it, freezing would be a bigger worry.

 

PS I experimented with flat plate collectors but with a small South west facing roof  opted for solar PV for the available space.

Edited October 25, 2021 by openspaceman

[openspaceman]

3 minutes ago, Puffingbilly413 said:

No I’m not - I agreed with the point. I was just saying I like my house cool inside in the summer.  I believe I acknowledged J’s point about insulation…

Okay  sorry if I misinterpreted. So we agree  good insulation  works both ways and a house with high thermal mass will have less temperature fluctuations with exterior insulation.

 

I still haven't attempted wall insulation  for my solid walls because it would destroy the look of the two tone bricks.