Air conditioner/heat pumps?

[fifthcolumn]

One of the main areas of life post peak we are going to have to solve (other than by dying off as per the doomers) is how to keep warm.

Given that we are going to be in a bidding war for the last dregs of oil/gas I suspect many of us are going to go for electric heating.

Since dissuaded a month or so back of the idea that halogen heaters are efficient enough I just did a bit of digging after reading a post on the oil drum about air source heat pumps.

Turns out you can get a fairly cheap portable one which is also an air conditioner for about 400 quid. You get nearly 3KW for every KW of electricity.

Sounds fairly decent to me as a solution. Might even be theoretically possible to run one of these off a B&Q windmill.

That along with solar water heating, rollout of electric cars en masse etc it's starting to look like the techno people are right that solutions are doable.

Now all we need to do is solve the pesky problem of soil depletion....

[Bandidoz]

Might even be theoretically possible to run one of these off a B&Q windmill.

Somehow I doubt that very much. I really don't like GSHP - a huge installation project, and a potential maintenance nightmare; if anything goes wrong there could be a lot of digging. On the other hand - at least it's "invisible" and hard to steal, compared to SWH.

[RenewableCandy]

Guys iirc air source heat pumps require no digging (use heat from air not from ground). The quid pro quo is their efficiency ("Co-efficient of performance") is less than the 3-to-4 found in GSHPs. The reason for this is the greater temperature difference (indoor air - outside air difference is greater than indoor air - underground difference).

Strangely enough ordinary electric heat from wind (tho' something a bit bigger than a B&Q job) seems by all accounts to work better than the theory predicts. My money's on the reason that the Average Brit house is rather drafty and that therefore the periods of peak heat requirement coincide perfectly with those of peak wind-turbine output. Will dig out the account of this I found, if anyone asks.

[kenneal - lagger]

The coldest temperatures experienced in our winters are generally due to high pressure, frosty weather when there isn't much wind. In such conditions 3kW might heat a room in the average house but a 1kW air source heat pump will only give you about 1.5 kW of output and a temperature of about 35 to 40 deg C: the greater the temperature difference required the less the Coefficient of Performance (COP). Unfortunately, heat pumps work most efficiently in the summer and air conditioners in the winter!!

If you've got the five or six grand to spend that such a setup would require, spend it on insulation, a porch on each external door and heavy, lined, full length curtains on all openings.

If you've got a large house, get one room, with a chimney, insulated from the rest of the house and be prepared to move the whole family into that on very cold days and nights.

Yes. a doomer I am.

[mikepepler]

I've talked with people who make GSHPs, they say that for efficient operation it is vital to insulate your house well, and ideally use underfloor heating, or failing that, oversized radiators. The reason being that the lower the temperature the heat pump has to generate the more efficient it is.

As for reliability, if you do it right the pipes underground are continuous lengths with no joins, so as long as there are no manufacturing defects then they should last for a very long time.

Also, with underfloor heating you can run the GSHP off-peak on Economy 7 tariff, as the concrete floor (with insulation under it) will keep the house warm through the day.

It seems to me that our heating strategy in the UK should be:
- insulate
- use biomass up to a sustainable level
- use GHSP/ASHP, with sufficient renewable energy generation to meet the new demand.

Otherwise we're stuck with gas...

[Neily at the peak]

A quick google (or other preferred search engine) of superinsulated houses or zero heat buildings will soon show how technology can keep us warm, Kenneal has a good argument that the cost of the heat pump would be better spent on insulation.

Renewable Candy I would be interested in knowing more about wind powered heat.

Neil

[Andy Hunt]

It seems to me that our heating strategy in the UK should be:
- insulate
- use biomass up to a sustainable level
- use GHSP/ASHP, with sufficient renewable energy generation to meet the new demand.

That's exactly the way it seems to me also.

It would be interesting to see what the sustainable level of biomass heating is - whether for example all the old terraced homes with chimneys could be heated with wood, and the larger semi- and detached homes using heat pumps.

Maybe there is a natural order of things in the solution.

[Erik]

One of the main areas of life post peak we are going to have to solve [...] is how to keep warm.

How warm do we need to be? How cold does it get in the UK? How feasible would it be to solve this problem not with technology such as heat pumps etc but with more simple solutions such as:

- (improving) insulation in houses
- wearing more clothes (no more padding around the house in a t-shirt in January with the central heating on full)
- greater numbers of people living in the same house

I just got back from spending a long weekend in a tiny village in the mountains in northern Spain where the temperatures in winter can easily drop down to -10?C at night, sometimes even lower. There were still many houses there that had no heating system whatsoever other than a wood stove to cook on in the kitchen). Admittedly, some of them (but not many) did still keep cattle on the ground floor over winter which must help (not recommendable for your typical terraced house or flat in the UK though!). One of the locals told me that they just "wore a lot of clothes" and were, well, "used to the cold".

[MacG]

I got good news and I got bad news.

The good news is that houses really don't need warming. The Earthship concept of evening out seasonal variations works just nice. Some elements of it in the Passivhaus

The bad news is that we have been building houses like we were complete idiots the last 50 years, and that almost every building around is hopelessly outdated and useless in a non-fossil energy world.

[mikepepler]

It would be interesting to see what the sustainable level of biomass heating is - whether for example all the old terraced homes with chimneys could be heated with wood, and the larger semi- and detached homes using heat pumps.

I looked into this for work about a year ago, and it seemed we were using roughly 25% of the sustainably available biomass right now. There were options to increase this amount quite a bit by planting, but that would be at the expense of whatever the land is being used for at present...

To access the 75% not being used right now there needs to be better woodland management, which as you know is something that Tracy and I are working to encourage!

[fifthcolumn]

To access the 75% not being used right now there needs to be better woodland management, which as you know is something that Tracy and I are working to encourage!

Not to sound like a hair shirt wearing hippy but...

It's interesting you say this. I was thinking about forests the other day and I was wondering if what we as a civilisation have maybe done wrong in our agriculture is overlooked the importance of the forest as a stabiliser of the oil.

Mulling over everything I have learned the last couple of years about soil and compost and terra preta and everything else, I'm thinking perhaps the four field, one year fallow system should really be a five field system where the fifth field is a forest and should always be left as a forest.
It would be necessary to extract some of the biomass from this region and put it into the fallow field to make it more forest-soil-like and make it more resistant to just blowing away in the wind. I don't know how big the forest "field" would need to be in area compared to the other four fields but I think it's an interesting speculation.

[Eth666us]

One of the main areas of life post peak we are going to have to solve (other than by dying off as per the doomers) is how to keep warm.

Given that we are going to be in a bidding war for the last dregs of oil/gas I suspect many of us are going to go for electric heating.

Since dissuaded a month or so back of the idea that halogen heaters are efficient enough I just did a bit of digging after reading a post on the oil drum about air source heat pumps.

Turns out you can get a fairly cheap portable one which is also an air conditioner for about 400 quid. You get nearly 3KW for every KW of electricity.

Sounds fairly decent to me as a solution. Might even be theoretically possible to run one of these off a B&Q windmill.

That along with solar water heating, rollout of electric cars en masse etc it's starting to look like the techno people are right that solutions are doable.

Now all we need to do is solve the pesky problem of soil depletion....

I have preferred electric heating(heat pumps) to gas heating system because I save energy and money...
The electric efficiency of turbogas plants is about 55 % so I save energy if I get around 1.5 kwh of heat(always in my living place) for every kwh of electricity...

[Ballard]

Heat pumps only work with extremely well insulated buildings, they also produce low temp supply (45 degrees or so), and so work with under floor heating only. Ok for new build, useless for existing houses.

If there was an easy and cheap way heat houses you can bet all the volume house builders would do it, they hate spending money if they don't have to.

I think you need to reappraise the massive amount of energy we currently pour into our buildings, to quote JHK

The idea that it's possible to get something for nothing is alive and rampant among those who think we can run the interstate highway system and Walt Disney World on bio-diesel or solar power.
People who believe that it is possible to get something for nothing have trouble living in a reality-based community.

However, New Zealand has a similar climate, and most of the houses have no central heating and no insulation and are built of matchsticks, they all seem to survive quite well.

[mikepepler]

Good thinking fc. I think every farm should have enough chestnut coppice to keep itself supplied in fence posts. The offcuts can be burned for heating.

The other thing for woodland is to make it a "food forest", where many of the plants are edible. Not so easy to change ours, as its ancient woodland so there are good reasons to leave it as it is. But we do at least get chestnuts from it - if the weather continues this warm we might get a good crop!