Moxi's cottage

[Moxi]

Ok

As some of you will know I've bought a little place for myself on the North Wales coast, it has solid stone/ slate walls approx 3ft thick, a slate roof at approx 30 degrees west facing and my elevation is approx 93 meters above sea level, (I get a good view of ireland on a clear day and cracking sun sets(not been too many of them so far though oops))

I have added 500mm of insulation to the loft spaces and 50mm PIR to the underside of the skielings and will be dry lining the walls and insulating the downstairs floors in the spring.

I have a 15yr old valiant ? (emblem of a rabbit or hare?) giving direct hot water fueled from LPG.  I would like to put up a solar water heating system and have read avidly through the previous posts and have a couple of questions that i would like to canvas opinions on :

1) Roof mounted at 30 degrees and west faced or gable mounted at 90 ish degrees and south faced?
2) Integrate to work with the boiler (boiler to be replaced later when funds allow) or a stand alone system?

In usage terms I'm there most of the time but other than a bath and washing etc I am a light user as the single occupier.  I would like to consider any of the three DIY packages offered on the Navi web site 1* 30 at 47mm, 2* 20 at 47mm or the single 20 at 47mm options.  I welcome any advice and guidance, if there's anything i have missed just ask,

Thank you in anticipation

Moxi

[biff]

all the best in your new home moxi,
                              the posse will be along to help shortly.
                                                           biff

[A.L.]

hello,

I would vote for 30x47mm on the roof or 40x47mm on the gable, the latter would need planning permission as it is not permitted development but it would extend the solar season and not increase summer overheating.

Fit a 150 litre twin coil cylinder with an immersion heater as even daytime electricity would be no dearer than LPG when part load efficiency (<50%) during summer is considered 

[brackwell]

Agree with A.L.

Using http://re.jrc.ec.europa.eu/pvgis/apps3/pvest.php you can see that for the same array size the 90/south produces 639 and the 30/west produces 750 (forget units a minute).
Not a lot of difference but it masks the monthly variation whereby the 90/0 produces Jan,  33.3  July 67 compared to 30/90 being Jan 16.7  July 112

I think panels should be at 90/south and where possible on a white background and with some reflecting surface in front and then this will surpass the 30/west (for the same size)

Ken

[Moxi]

The white background is easy as the cottage is rendered and painted with a white/ cream background, so as long as i can get planning permission the wall mounted option offers more usefull heat through the colder months, thanks A.L and Ken thats been very helpfull 

Moxi

[rhys]

Not sure if Cottage is listed or in a conservation area. If not wall mounted may be OK.
Rules for Wales are here
http://www.planningportal.gov.uk/permission/commonprojects/solarpanels/

[Moxi]

No its not a listed building and we are outside the national park so it looks as though its permitted under the legislaton, thanks rhys that was a nice bonus for the end of today

Moxi 

[rhys]

Check and confirm with your planners, but  they often get the rules wrong, so be prepared to argue and if necessary quote the circular, not just the planning portal!! Some districts charge for confirmation of permitted development rights, may be worth the fee, if they won't give you verbal confirmation.
In the Plannng Office, most councils operate a Duty Officer service, who may or may not be helpful!!

[knighty]

does the LPG boiler heat radiators as well ?

if it does it's quite unusual for a 15yr old boiler to do heating and direct hot water in my experience...


how you plumb in the solar depends on how your system is currently plumbed



if you have a model name/number we might be able to figure it out for you :-)

[Moxi]

Hi Rhys, I will give the duty officer a call and try that as an approach.

Knighty, the chap that owned the cottage (my neighbour) said he thought it was about fifteen years old, I'm working on a station today but when I get home tomorrow I will look out the model number.  It runs both the hot water and the central heating there is a rocker selection switch with a rubber cover over it to select, the timer is the old type rotary unit with pins to select on off periods.  Its a valliant (rabbits head) and looks fairly old even to me.

I will take a few photos of the boiler and the pipe work and try to load them up next week when i have good IT access.

Moxi

[knighty]

cool

I'm just thinking..... you pretty much have 2 choices

either setup your solar tank and use that to feed pre-heated water into your LPG boiler - you'll waste a bit of lpg as the dead leg of cold water in the pipes works through the boiler, but then if the water is up to temp the boiler should shut down....
(I guess you could add a 3way valve at the boiler, so in summer you could bypass the boiler entirely, and then turn the valve in the winter so the water goes through it?)

or...

you can have 2 coils in your hot water tank, 1 solar (at the bottom) and one for the lpg boiler (higher up), then use that tank of hot water directly
(adding a 3 way valve and using your lpg boiler as a system boiler)



I'm not sure which system would be better for you.... there's probably not much difference between the two

[Moxi]

Hi Knighty,

Thanks for the post, I failed to get photos but the boiler is A Vaillant VCW-GB242 or 282 EH (not sure which as there is no indication on the boiler and the instruction booklet doesn't distinguish between the two)

I think option two is the better option for me as I'm away overnight quite a bit and I prefer a bath to a shower so the tank has the opportunity to accumulate heat for up to 48 hours before i might call for water and where water has not got hot enough the boiler would run for a period to heat the tank which is more efficient as the boiler gets hotter  rather than what it does at present which is comes on for 4 minutes then goes off when i run a bowl of water to was the pots.

Thanks  I can move to phase two now and ask for quotes from the navi installers in my area.