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Sunuser Ltd (UK)

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Posted by dazzaxe on March 9, 2005, 10:55 pm
Hi all,
Has anyone in the UK had any dealings with Sunuser Ltd.  They are based in
Leeds.  We're thinking of buying their solar powered water heating system.
Any recommendations / horror stories about these guys?

Posted by dazzaxe on March 9, 2005, 10:59 pm
Hi all,

Has anyone had any dealings with this company based in Leeds.  We're
thinking of installing their solar powered water heating system.  Any
recommendations or horror stories?


Posted by Nick Rouse on March 10, 2005, 4:43 pm
I  have no knowledge of them but I note they are not members of the
UK Solar Trade Association
and not approved by the Department of Trade
ClearSkies scheme.
This means that you will not be able to get
your 400 grant. If they say that they will give you this as a
rebate and claim it back off the government themselves (as some
of the cowboy outfits in this business are doing) they are lying.
By not being in either of these schemes they are not obliged to
to give you a cooling off period if you sign up with them.
I would ask them why they are not members of these schemes and
treat their responses with caution. Also ask who makes their
solar collectors and look up their web site. Most of the better
manufactures give technical data. Find out the expected yield
and see if it corresponds with the expected savings they have
promised you. In the UK the solar energy falling each year on
1 square meter of a south facing roof inclined at 30
is between 1200kWHr  and 800kWHr. There is a good map on
the Solar Trade Association site. Multiply this figure by
the aperture area and the efficiency to get the annual
yield. The efficiency will be in the order of 45% to 65%
Don't believe any higher claims.
If you have any difficulties let me know

Nick Rouse

Posted by auto on March 11, 2005, 7:31 pm
 why not go for a Navitron panel - their panels are the much higher
efficiency evacuated tube type and the price is probably no more than for
a flat plate panel. (navitron.org.uk)


Posted by Nick Rouse on March 12, 2005, 12:59 am
Your web site is not operating and looks like it would be quite
primitive when it is so I could not get data on the system you
are offering.
The relative merits of non-evacuated glazed panels such as I
see Sunuser supply and evacuated tubes you offer in a relatively mild
climate such as the south of England is not as clear cut as many
salesmen of evacuated tubes like to make out. The efficiency at zero
temperature differential between the external air and the circulating
water and with high insolation is about the same when compared on an
equal aperture area basis. The efficiency of flat panels drops off
far faster than evacuated tubes as the temperature differential
increases and also as the insolation level drops. However this
increased retention of efficiency is bought at the cost of reducing
the proportion of the gross area that is an effective absorption
area as the area is sliced up to fit in the tubes. Reflectors can
buy back some of the loss but not all. Since most users are not
running up against the limit of the available roof area you can
compensate for lost efficiency by bigger panels so that it is then
down to cost. Flat panels are usually a fair bit cheaper per square
metre of aperture area.  If you equal up the total annual yield
you will finish up with a more peaky annual cycle with the flat
panels and may throw away more of your potential summer yield and
have an even lower percentage of winter hot water requirements
but you need to evaluate the yield per cost for each proposed system
and not place too much faith in salesman's promises or even of
letters of commendation from users. Few users keep very accurate
tallies of savings. There is at least a three to one ratio in
the costs from different installers in the UK for equivalent systems
with some of the biggest and most advertised giving the worst value.

On the original question of Sunuser, I see that they were taken
to the office of fair trading in 1998 because of their terms of contract
They were also the subject of an Early Day Motion in parliament
by Julie Kirkbride MP although weather this was to praise them or
damn them I don't know as the online records do no go back that far

Nick Rouse

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