Member postings for Peter Bell

Thanks for the advice Stuart. Good idea t get a demo, not near any of the stores but sure we can do something about it. Some systems very fancy (and pricy) !

Tried Hi-Fi through TV previously with mixed results so dont really wnat to go that route again.

Stuart, Your comments and setup are interesting as I have just got a flat screen TV and now realise after experimenting with settings that I'm going to have to spend to improve the sound quality. Speech is fine for me but overall it sounds very much like its coming from a tin can. The previous CRT 20 yr old Phillips TV sounded great!

So looking around and of course so much to choose from, are home cinema kits much of a step up from sound bars and is a "modest home cinema setup" just a smaller/cheaper version of a larger outfit?

Peter

Yes agree, thats often the case, the real world figures of anything are vastly different to the test results and the ASHP is just part of the muddle. I had to do something about my heating system and the way I've "split it" seems succesful so I'm pleased with the results, the ASHP could be changed for a more efficient gas/oil boiler or even an improved HP. There is the threat of Stirling cycle and two stage HP which are supposed to be more efficient so I regards my experiment as meeting my objectives but only at the moment.

I'll be interested in how your views develop and the results of any actions.

Peter.

Hi Steve,

I did very similar to what you are suggesting (see pic) so I retained the use of the original boiler if I wanted it, in practice never used it for ages. Sometime think it would be useful to do a costing of each system but l'd rather do something more interesting....

Think our original themal store was around 300l but replaced this with a 90l thermal store and presurised SS cyl which I think is 150l. I hoped the SS cyl would be less prone to leak /corrode and seems fine up to now.

Not sure what the COP is when its in block of ice mode but the parameters for a defrost can be set, think I've got mine set for the min of 1/2hr continous running also taking into account the condensor temp.

Being a "budget" ASHP its suffered from spade connectrors overheating/burning, replaced with eyelets onto the existing studs and capacitors failing. I've replaced the start and run caps with decent run polyester ones. The two schroll compressors are Toshiba. It also has 2 fans pulling air through the condensor. Earlier this year I noticed one fan seemed slightly slower than the other so removed panels etc. When I put my Smiths tacho onto the top fan discovered it was doing 500rpm and when pushed the tacho onto the bottom fan it slowed and stopped-mmm! More digging revealed that the fans are 960rpm and the caps had gone from 4uf to 1.5uf. Changed these and its producing a howling gale once again which should improve the low temp performance and perhaps help keep the condensor freeer from ice. Not sure how long its been running at the lower effiency though.

I still have the smaller ASHP sitting in the garage Steve but unfortunatly I'm in Staffordshire else you could have had look at it all and even borowed the smaller ASHP to try/play.

Peter

Yes indeed and the first commercial installation to heat a large building used water from the river Wensum in Norwich as a heat source. This was designed and built by John Sumner and started opearation in Oct 1945 but only lasted for a couple of years due to corrosion of the plant and nationalisation of the electricity industry.

Peter

Steve, Just re-read your post about damp climate. Our does freeze up but still works when its a block of ice until it does a defrost cycle which looks pretty impressive but as you say the COP is pretty poor at that time. I've heard of problems with ground source HP due them freezing the ground giving poor themal transfer especially if its dry or sandy ground but not got direct experience of them.

Only advantage I can really see from my experiment is that they do work and the electricity can come from any source green or otherwise but they are definatly not a direct replacement for a boiler on cost and output temperature as most posters have outlined.

Peter

Yes I changed the cyl Steve. Perhaps better add that we are a new build from 2000 but not terribly good on insulation, wanted better but building regs awkward/dodnt understand at the time. Also have heat recovery ventilation which is excellent.

The original system used a large cyl which incorporated a thermal store and heat exchanger for the underfloor but was designed to run UF at 65/70C. Not very good for effienciey but nice and hot as was the house, and used lots of oil. Cyl was showing signs of leaks at the time of the small HP experiment.

Now run UF from a heat exchanger direct from HP, output from heat exchanger goes to a dedicated thermal store then pumped back to the HP. This prevents the HP cycling. When the thermal store is up to temp(48C) HP is off and another pump circulates the contents of the thermal store to the UF heat exchanger. At 42C HP it changes over and HP on again and the cycle repeates. Could have just circulated HP to thermal store but this way UF get the benefit of quicker temp rise.

I have motorised ball valves to change HP over to heat the cyl as needed, can be automatic but cyl has seperate thermostats to control HP. As most of the time a lot of hot water is not needed run cyl at 35C and have undersink instant elec heaters to boost to 50C which also works for the shower.

The UF piping is plastic/rubber as was designed for us, could be better on heat transfer especially through carpets. If I was doing it again would use rads and UF but circulate to rads then onto UF on return from rads. Did this on my sons house(gas fired) and it gives the best of both worlds, UF heating very nice and cosy!

Peter

I became interested in heat pumps after read ing a book in the early 60's in the technical college library called "Domestic heat pumps" by John F Sumner. Of course at the time nothing was know about them but as the years have chugged on they have become more to the fore and I always thought that some day I would experience a heat pump.

Our house has underfloor heating with an oil boiler but eventually I got fed up with oil cost so rejigged the heating and installed a 7kw output heat air source pump which worked reasonable well but didnt have enough grunt. Changed this for a 22kw output ASHP (Ebay) and the oil boiler has not been fired up for 6 years now so some sort of a success but I'm sure I'll hear more!

Not for everyone I'm sure as can be noisy depending on location and gives running cost somewhere near gas. Major disadvantage is it cannot reach the same temps as a normal boiler so not an instant swap for a gas boiler in most cases.

Peter

Dave, Interested in your comments re Dynamometer project and using 2 Arduino with one for the display. I've tried doing this but failed miserably earlier this year so wondering if the code is around anywhere as original Dynamometer project is on the WDMS website or failing that if you have anything you could share?

With the approaching darker nights feel some Arduino coming on!

Thanks Peter

Yes I could not find the forum so assumed it had gone and thanks for the alternative.

Thanks also for the explanation on the hub, looks idea. I had looked at static loads previously and everything was way over what I need. Think its going to be around 140-180kg total and it will be based around the cenre so is balanced.

Peter

tAbout the size I was thinking of but that hub looks like it slides onto a splined drive shaft so the bearings are in a separate housing, if I'm looking at it correctly!

Did a bit more searching and slew bearings everywhere like elevating platform etc, often combined with a motor to rotate them, probably similar on fairground rides but I'll bet some of the ancient stuff used a lorry front hub.

Yes the tube idea is a possibility--thanks.

Tried Navitron previously on other things so maybe worth a go--thanks.

Rotation of PV arrays is not popular because of the obvious complications and its normally reccommended to install extra panels to compensate but dont want to do this!

Peter

I'd looked at bearing like used on a washing machine etc but all are too small/flimsy. On the other hand there are "proper" slew bearings as used on 360 degree excavators etc but very pricy /large to experiment with.

Its a single axis tracker I was interested, single pole mount is quite popular around the world and even in the UK.

This is a similar size to what I am doing. The support is very much like a roof with the panels attached to the correct alloy rails with clips

However it is fixed, I want mine to rotate as the next step, hence the question in case someone has already done it or has practical experience of it.

I may end up with a grid ties inverter etc but it's heating water, matched to an imersion heater. At present its running at 156v and 312w in todays cloudy conditions, full sun is 1100w.

The link below is the controller I am using. It matches the impediance when the sun is not shinning fully. Works very well and the link gives comprensive data as well as a working project.

Peter

https://create.arduino.cc/projecthub/stevetearle/loadmaster-xp-a-smart-pv-mppt-solar-hot-water-controller-4a813f

Thanks for the messages eveyone. They are Photovoltaic panel, 5 of them.Yes they will be out in all weathers and windage is an important consideration which is why I was asking in case anyone had seen or have experience of a commercial installation and could recall the bearings type or how it was made up?

A lot of the info out there does not really go into the detail I am looking for, I have seen plain plastic (for wont of a better word!) bearings advertised which is what I suspect the commercial installations use. I only picked on a rear hub type arrangement as an alternative as they are robust and readily available.

Peter

Thanks for the reply. If I used a suitable rear hub complete with bearings etc I was going replicate the original stub but make the length reasonable as it would be inside the pole/tube to avoid over stressing the welds.

Is that what you mean?

Hello, I Have 5 solar panels for water heating which are doing a good job. As part of the experiment I intend making these into a pole mount so that I can rotate and track the sun. I have worked most details out like tracking electronics (arduino), pole and mounting frame.

I wonder if any of our readers has seen a suitable installation and can describe the slew bearing or bearing assembly?

Initial thoughts are to use a front wheel drive van rear hub which has taper rollers, probably, overkill but readily avalailable?

Thanks Peter

Thanks for the suggestions but no sensors or batteries (hidden or otherwise) on the actual door also no batteries in the unit, its all mains powered. The fault appears and it stops working witout moving or being touched, only a mains switch off/on gets it going again.

But it's worked this morning!

Thanks for even more helpful comments.

Changed the capacitor, it measured 220uf down from 470uf. Now doesnt get warm but I dont think thats the problem. I can make it display a 5 for overload if I hang onto the door while its moving. but my fault is 4 while its standing doing nothing.

Maybe quite a sophistcated unit with suspected pwm to slow the door as it's nearing the end stops. Think these are set as part of the installation if I remember correct. As its probably some microprocessor problem dont expect its easily fixable so another unit to try maybe a better option. Maybe manual operation is an easier option! This is a 550Nm unit, the ones on ebay are 1000Nm so probably quite old.

Thanks for the offer, shall I send a PM John?

Peter

Thanks for the helpful comments.

When it was stopped the unit had clicked off. I've put my clamp on meter on it and switching off fine. Transformer Volltage is 27v but dc to the motor dips as expected on load but a cap on the board is getting very hot. Its only 470uf which seems a very small value for a smoothing cap.

If nothing else reckon I've found a wasps nest!

Peter

Yes its all running fine/smooth on the mech side.

Working in the garage earlier with eth door open it put 4 on the display and stopped working after a few minutes without being touched or moving.

I'll have to explore the unit more.