What did you do today (2015)

[V8EngParticipant @v8eng]

 

Posted by Speedy Builder5 on 07/11/2015 11:03:47:

What I feel is a blot on the skyline is solar panels which are just 'dumped' onto a roof. Why can't they be tailored to completely cover a roof so they look like they were meant to be there in the first place. COST – but then what is the 'cost' of living and looking at these hideous additions.
Grumpy BobH 

 

Some "new Builds" seem to have have very well integrated Solar Systems on thier roofs.

A case in point is a on a small Apartment Block located in a town I pass through on a regular basis, they were built a couple of years ago with slate roofs, the solar panel sections were fitted (flush) at build stages and look just like the surrounding slates.

Looking casually at the buildings you would not easily see that there is a panel installation, especially now that everything has weathered.

I wonder if adding weight to roof structures has something to do with limited panel quantities on retrofits?

Edited By V8Eng on 07/11/2015 14:27:29

Edited By V8Eng on 07/11/2015 14:29:58

[Clive HartlandParticipant @clivehartland94829]

One of the tile making companies does have Photo Voltaic tiles and they mimic standard tiles in shape and size. Redland springs to mind, Ideal as an initial roof build.

Clive

[Michael GilliganParticipant @michaelgilligan61133]

Just came across this rather ambitious ebay listing for a John Wilding book.

They have two copies available

MichaelG.

[NJHParticipant @njh]

Ah

I have a copy! –

I might be prepared to knock off the 26p when I offer it for sale!

Norman

[Neil WyattModerator @neilwyatt]

I have some discussion with a group who are planning a trial of 'Energiesprong' in the UK. In short they take a property, clad the outside with insulation and new windows, fit a solar roof, rip out all glass appliances, fit a new kitchen, air- or ground-source heat pumps and a new bathroom.

The Dutch installations have achieved 'zero on the meter', and because the whole thing is fabricated off site (following a millimetre accuracy laser survey) the actual fit takes less than a week and the residents don't have to move out.

Aimed chiefly at council and housing association properties, in the Netherlands it has worked so well many private owners are going for it.

**LINK**

I have seen photos of a few of the fit-outs and the houses look much better afterwards, so I'm very interested to see how it goes in the UK.

Neil

[David Clark 13Participant @davidclark13]

Hi Michael They often put up high prices and then drop them. I suspect a gofor lists them and then somone with a bit of common sense sets the correct price. The other reason is they don't have it in stock but want the listing to continue indefinitly so it looks like they sold lots of them.

[David Clark 13Participant @davidclark13]

I lived in Scotland for about 4 years and often drove past wind turbines. They often made me feel dizzy as I drove past them.

They also had small turbines at the local Tescos on the roof. They had a habit of the blades coming off and wrecking cars in the car park.

[AjohnwParticipant @ajohnw51620]

Ground source heating aught to be the cheapest option really. Bore hole / buried pipe networks and a freezer sort of arrangement which gives some idea what the gear would cost if some one really got down to making it in volume.

This touches on the problems with "green technologies". Subsidies aimed at helping with start up costs with larger items in real terms tends to attract people who say hey I can make some money with this and don't really do anything useful in terms of getting costs down and just moan when the subsidies go.

The other problem for consumers is pay back time. That can be rather surprising if some one takes the time to work it out. I looked at converting a car to lpg once. Bit of a joke cost wise but at the time that may have been down to every man and his dog becoming conversion specialists. People can also buy things for a few hundred quid that are pretty dubious. I was always fascinated by ebay sellers offering certain motors for home made wind "turbines". Even B&Q sold something that might keep a light on but not much else at that sort of price. Then there were people making and selling units which extracted heat from the outside air – heat pumps aka freezers again.

On the plus side though when central heating was installed in our house – it was on economy seven. I wasn't at all happy with the plumbers that came and looked so did the sums myself. Also had the gas people in and the surveyor happened to see my sums when he was looking around. He told me he had come up with the same numbers. Still not happy and had come across some flow rates and radiator heating information through 10mm pipes. For a certain size of radiator there is a max pipe length related to bore. No one would do this so did that myself. Plumbers came up with crazy boiler prices so went and bought one myself and then got some one in to finish off. Most of the info came from some one that was determined to get some science into central heating and they made some interesting claims about radiator valves so I fitted those when I installed the radiators. Radiators sized on the basis of efficiency from the science man, they run cooler than what was usual at that time. The boiler has an in built heat store. The idea being that a bath can be run, water will cool but not go cold and 4min later another bath can be run. It runs full whack to heat the water and around 1/2 power for heating. Sums suggested that heating would need to be turned up to near full whack. It never has been and we haven't been cold – thanks to simple wax stats on the radiators. The boiler will be replaced soon so has to be a condensing boiler. Thanks to the radiator sizing that will be far more beneficial to us than it will be to many people having them fitted as a replacement for an older boiler. Biggest problem is the heat store. The manufacturers tell me we want one that is truly very much larger than the one we have been using which means that it will take a lot lot longer to heat up if it cools. The house is generally considered to be too big for a combi. Hot water was supplied by 2 powerful gas instant water heaters when it was on economy seven.

Light bulbs – for much of the year in the UK filament bulbs produce useful heat when they are on a lot. The heat has to come from somewhere.

Street lighting – became a lot more widespread when electricity companies offered electricity for them cheaply as much of the time they are on during off peak periods. Some councils fit high cri led lighting. These are less efficient than low pressure sodium. When ever the lighting is changed it always provides higher light levels as well.

Green ? makes one wonder. More like an opportunity to rip the general public off.

John

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[martin perman 1Participant @martinperman1]

My brother looked into ground heat pumps, when the company he picked came to see him to quote they told him his 200 foot x 60 foot garden wasnt big enough to justify the outlay, he settled for water and electric solar panels on his roof which are working well.

Martin P

 

Edited By martin perman on 07/11/2015 17:47:28

[AjohnwParticipant @ajohnw51620]

Martin I understand some without much space have gone for a bore hole but no idea how deep or costs.

They use solar water heating in Turkey, extensively. Just a barrel on the roof and pipes sized to allow convection to circulate the water.

John

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[JAParticipant @ja]

Superficially the heat pump appears to be a very attactive device for heating. However there is a major down side – the heat source, which is the cold side of what is essentially a refrigerator, should be relatively warm to keep the energy used to move the heat low. If the cold side is buried in the ground, during cold weather the ground will freeze solid so increasing the energy required. The volume of frozen ground will then get larger and colder without any warmth arriving making matters even worse.

I believe the Festival Hall in London was heated by a heat pump using the Thames as the heat source. However, I guess, the Environment Agency would have something to say if I did the same with my local river which is usually not much more than a trickle of water.

JA

[Bob Brown 1Participant @bobbrown1]

John,

What size boiler do you think you need as they do gas combi boilers up to 40kw (hot water) but you would need a large water flow (hot water) for that kind of heat input. I have just done our 3 bed bungalow with a Baxi boiler (28kw) that modulates the burner depending on the demand both hot water and heating. The system is some what different from the norm as I fitted a manifold in the loft with a 8 way control valves and wireless stats in each room so no need for rad stats. Each "Radical" rad is individual fed in 10mm copper, do not like plastic, with pipes out of the wall in the middle of the rad (connections in the middle rather than ends), rather than up from the floor so no ugly pipes to be seen and so far the system has run really well. A bungalow has a bigger roof area than a house as the footprint is bigger but I did insulate the roof (not ceiling)with 120mm of Celotex 60mm between and 60mm over the rafters which took it above current standards but thought as I was replacing the roof tiles it was the way to go..

Bob

[BazyleParticipant @bazyle]

If you wan to get seriously into energy discussions try the Navitron forum. Lot of sensible people on it without the weirdos on the greeen forums. The ground works for borehole are roughly twice the cost of the trench system which in the UK are about 6-8ft deep to gather mostly earth core energy – yes that's right not solar heat. However in some countries like Norway trenches are often shallower, insulated by deep snow in winter and picking up more solar than earth core heat in spring / autumn.
Heat pumps may be eco but without the subsidy are long term uneconomic as they wear out just as they are paid off from savings. Someone in the village has installed an air source heat pump. They don't hear it inside but the peace of the night is lost. Wouldn't like to live close to them as I like the bedroom window open.

[Clive HartlandParticipant @clivehartland94829]

The building we worked in Milton Keynes had plastic pipes in the concrete base. These were supposed to cool the concrete and they had fan units in the floor blowing into the underfloor space and over concrete to cool the air.

Outside they had a cooling tower that had a fan up draft, this whole set up was costing approx £3700 per annum on top of power requirements. This being the twice annual maintenance and Biocide costs.

You may guess the out come as women sitting over or close to the floor outlets wanted to move as they started getting a frozen leg syndrome. In the end I recommended turning the whole system off and there were no more complaints and it cost less. From this I learnt that the soil was a standard 11C temperature and was very stable as we monitored the system 24/7 with recorders.

Clive

[NJHParticipant @njh]

" Someone in the village has installed an air source heat pump."

Oh dear Bazyle – guilty as charged I'm afraid – we have just installed one ! It has a largish fan and I guess it does produce some noise close by. In mitigation we are not close to other properties in the village. These pumps are quite popular here and several of our neighbours have them. It is early days but (I hope!) it will be the solution to our heating problems. Up to now we have been dependant on oil fired central heating (and big price swings) plus a woodturner – there is no gas out here in the sticks. It is, it seems, a different philosophy of heating – it is not hot but an even, comfortable, temperature throughout the house at all times.

( My wife also insists on an open bedroom window at night – we will see how that pans out in the colder weather!)

Norman

[KWILParticipant @kwil]

Nobody has mentioned it, but if you are on the gas supply grid going for solar/air or ground sourced heat will cost too much. Pay back periods exceed the time the average occupier stays in that house and I for one would not be too impressed with a higher house price just because of "eco" heating.

Heat pumps have a "gain" factor (Coefficient of Performance or COP) of 3+, ie for 1Kw electrical input you pump 3+Kw of heat, but then electricty power costs 3x that of gas power, so where is the advantage? The factor would need to be at least x5 plus low unsubsidised install cost to be attractive.

Edited By KWIL on 07/11/2015 23:17:40

[KWILParticipant @kwil]

Norman,

Never open a window, I have the advantage of a Mechanical Whole House Heat Recovery System, air and hence heat (+ water vapour) is drawn from Kitchen, Bathroom etc and dumped to atmosphere via a cross flow heat exchanger which warms the incoming ai, which is piped to all the other rooms. End result, clean fresh warm air and no need to open the windows at night!!

K

[AjohnwParticipant @ajohnw51620]

Posted by KWIL on 07/11/2015 23:17:08:

Nobody has mentioned it, but if you are on the gas supply grid going for solar/air or ground sourced heat will cost too much. Pay back periods exceed the time the average occupier stays in that house and I for one would not be too impressed with a higher house price just because of "eco" heating.

Heat pumps have a "gain" factor (Coefficient of Performance or COP) of 3+, ie for 1Kw electrical input you pump 3+Kw of heat, but then electricty power costs 3x that of gas power, so where is the advantage? The factor would need to be at least x5 plus low unsubsidised install cost to be attractive.

Edited By KWIL on 07/11/2015 23:17:40

That's what I was inferring earlier also that prices are artificially high because people are "saving money" or so they say which in many cases they wont be considering how long it takes to recoup the cost. It also gets less attractive as people age. There comes a point in life where people are unlikely to ever recoup the cost.

Condensing boilers don't work out too well when installed on older systems either as they generally don't have sufficient radiator area. To make best use of them systems need designing from scratch specifically to suit this style of boiler so that it can actually condense. There is a bit about that here

**LINK**

The problem is that prior to this style of boiler being used the design temperatures were too high and a lot more radiator area is needed to make good use of them.

John

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[BazyleParticipant @bazyle]

grrrr. Workshop dehumidifier made horrible noises (3 yrs old) so replaced with Dimplex from Screwfix. Just been to workshop and find new water sucking machine sitting in a puddle. Assume something wrong with drip tube so looking into that when I see the tank which I had taken out and set aside was now sitting in a puddle. The moulding ingate left a small hole right in the middle of the bottom. Few seconds with soldering iron has it sealed but I now have 2 damp patches in the chipboard floor. Hope it dries this out before they have a chance to swell.

[KWILParticipant @kwil]

I installed a condensing boiler some 3 years ago on a system which I designed and fitted 27 years ago. The exhaust plume indicates that it condenses most if not all of the time.

Flow temperature is controlled by reference to the outside temperature (ie weather controlled reference). All Rads are fitted with wax thermostats for room temperature control and the master thermostat is fitted in the inner hall where there are no radiators. When the time clock shuts the system down there is a fall back (night set back) temperature level set which over rides the clock if the core temperature falls due a sudden overnight drop in temperature.

Result, economic constant comfort levels, properly controlled. All floors, ceilings and walls are more than fully insulated with complete double glazing.

[Ian S CParticipant @iansc]

In Christchurch NZ, open fires are banned, and only approved closed log burners are allowed, but the form of household heating that is preferred is the heat pump, and after the 2010/11 earthquakes heat pumps were supplied to replace damaged fire places.

My heating is by a Night Store heater, a pile of bricks heated by electric elements, it is switched on and off 11PM, 7AM by the same ripple control that switches the hot water cylinder(this is at a cheaper rate than the normal heating and lighting)

The Christchurch Drainage Board uses bio gas at the sewerage works to make fuel for it's vehicles, and to generate electricity with two old, large diesel engines (ex marine, about 5000hp each).

Ian S C

[MuzzerParticipant @muzzer]

Lots of cynicism about heat pumps and condensing boilers on here, surprise, surprise, much of it anecdotal, ill-informed or simply urban myth.

I got an air source heat pump fitted in our house in Canada when the original system started to show signs of corrosion after 30 years. The system is very similar to a standard aircon system, ie well proven system compts, the main difference being that a heat pump is bidirectional. It all sounds terribly mysterious but it's basically just a heat exchanger that can operate in either direction. Essentially during the summer, the outside heat exchanger of the heat pump is hotter than the outside world (and thus cools the house). In the winter, it is cooler than the outside world and consequently heats up the house. We retained a gas-fired furnace as a backup and for when the ambient was below 0C but in practice we hardly ever needed it (Vancouver weather is like the UK). Many people simply have an electric heater to boost the system in the winter but in our case the house wiring would have been a problem. Didn't actually cost a lot more than a std system to install and there were grants available to subsidise more efficient heating systems, rather like in the UK.

The reason heat pumps are lower cost is because of their thermodynamic coefficient of performance (COP) which is something like 4 or so for these systems. A COP of 4 would mean you only pay for 1kWh to create 4kWh of heat effect, unlike an electric heater which has a COP of 1. So even if you are using more expensive electricity to power the system, it uses less energy and still costs less than gas or electric heating – with the benefit of aircon in the summer months. In many cases you can do away with the gas / oil / electric heating altogether.

The system components are very well proven, as they have been is use for many years across the world within aircon, refrigeration and heat pump systems. Our system came with a 10 year parts and labo(u)r manufacturer-backed warranty which wasn't unusual. Externally (hidden behind some bushes), there was a heat exchanger with a fan inside it that was about big enough to hide inside if you removed the guts. It wasn't much noisier than many modern condensing boilers (which also have a fan).

Not so convinced about ground source systems, given the extra installation cost and effort. One of the main obstacles to heat pumps in the UK must be the low demand and lack of awareness. This must push up the cost and probably limits uptake to mainly the eco-warrier / tree hugger minority. Pity – as they have a lot going for them.

Murray

[Neil WyattModerator @neilwyatt]

Posted by Ian S C on 08/11/2015 10:54:37:

My heating is by a Night Store heater, a pile of bricks heated by electric elements, it is switched on and off 11PM, 7AM by the same ripple control that switches the hot water cylinder(this is at a cheaper rate than the normal heating and lighting)

In the UK we have timers on our meters that do the switch over – has the major advantage that the switch times of each installation is different (by up to an hour or two) so you don't get them all switching together.

> Not so convinced about ground source systems

Agreed, ground source really only makes economic sense if you have a really big installation and is best done as a borehole or using a water body that doesn't freeze. The problems come when too much capacity is squeezed into a small space.

Air source heat pumps are ideal for most UK domestic situations.

Neil

[Gordon WParticipant @gordonw]

I've just finished installing an air-to-air heat pump, this is our second. The first one worked well but the electronics gave up. the problems were very similar to what I was reading about lathe speed controls. Our pump heats one large room. It feels like a 3kw fan heater but draws about 3-4 amps, and then not for long. Ideal for autumn-spring weather but does struggle when outside drops to -10. Non-scientific calcs. show it is cheaper than buying in hardwood for log-burner and a lot easier on the old back.

[BazyleParticipant @bazyle]

Unfortunately the UK market is distorted by regulation and profiteering, labour costs etc so a £1000 heat pump in Canada becomes £3.5k in the UK. Mild climate reduces use and extends payback time. COP falls dramatically below 5C source heat (when the gas mix is tuned for UK temperatures) so bad just when you need it and when using 'economy 7' (original 8 hour cheap rate in the 'sixties was reduced to 7 hours in the 'seventies once they had got millions signed up). Ground source is never <0C so has advantages there.
If using domestic airconditioning (rare in UK) a bidirectional HVAC system makes more sense.

Anyway in workshop damp patch next to dehumidifier dried overnight but he smaller one 4ft away has only just cleared. So it's not just Chinese made lathes that have defects.

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