Gravity type solar heaters

**DrAndy** · 31-10-2011, 11:45 AM

Originally Posted by Butterfly

your pic is small, but yes your tank is better looking

the question remains that they seem to be a pain to install, above all when most Thai houses are equipped with only "cold" water canalization and only "local" water heater pipes in the bathroom

of course you have to add hot water pipes! if adding to an existing set-up it can be extra work, but nothing substantial

both mine were put into new builds

**DrAndy** · 31-10-2011, 11:47 AM

Originally Posted by Butterfly

still quite big,

I assume you currently use something else in your house to heat the water ?

I am using a plate version, which can be pumped through

they look similar but instead of the glass pipes they have a flat plate with finning inside, like radiators

they are great; once fitted the free hot water is available anytime for any purpose

I had the small one set up on the ground and tried pumping out of it, but my pump didn't like hot water!! I think you can buy special hot water pumps but they cost a lot

**gammelnok** · 31-10-2011, 03:04 PM

Please excuse me for trying to take advantage from your tread.

I really like to understand the difference between the 2 types of panels mentioned here.

If going for a pressuresed split system, do you say, that the flat panel system is to be preferred to the glass tybe system?

What are the advantages of the one to the other if any?

Enjoy the day

Thank you
rasmus

**benlovesnuk** · 31-10-2011, 06:25 PM

Hi, i will try to answer your question.

Tubes are cheaper and an update from plates, they have the ability to caych more sunlight because of their shape. The panel version is more expensive, probably because it uses copper, it might be worth checking your water source as the type you get is dependant on that.
For example copper pipes might close up, over time from sediment. As water in a seperate system doesnt flow through the tubes this is not a problem. Normally tubes cost about 1000 baht to replace and are easy to exvhange. I would reccomend Abo trading if near chiangmai.

For the moment Dr.A ive been persuaded to a new system, split tank,however if my guesthouse needs a seperate panel, i will let you know.

sabaii sabaii · 31-10-2011, 10:50 PM

Originally Posted by DrAndy

I have two oldish solar water heaters for sale

Originally Posted by DrAndy

not sure how old

Originally Posted by DrAndy

I originally picked them up from Bangkok

So you forgot when you bought them ?

Originally Posted by DrAndy

they are excellent devices and work well

Originally Posted by DrAndy

I tried pumpng out of one of them but the hot water ruined the pump

Oh dear

Originally Posted by DrAndy

free advice comes with them

Originally Posted by DrAndy

get free hot water

Originally Posted by DrAndy

save yourself a fortune and get free hot water

No such thing as a free lunch

Originally Posted by DrAndy

offers invited!!

**DrAndy** · 02-11-2011, 08:56 AM

^ I got them from a dealer who had used them as demo models, and that is why I have no idea how old they are

so, no, I didn't forget

Originally Posted by gammelnok

I really like to understand the difference between the 2 types of panels mentioned here. If going for a pressuresed split system, do you say, that the flat panel system is to be preferred to the glass tybe system? What are the advantages of the one to the other if any?

the glass tube system is the simplest and cheapest system, but cannot be pressurised. So if you don't have them mounted on the roof or on a tower, you cannot use them

the flat panel types can sit on the ground, be pressurised so your pump can distribute water through them to your house, but they are quite a bit more expensive

the two I have are in used looking condition and are cheap, so if anyone needs them, let me know

there has been quite a bit of interest and only a couple of fools

**Marmite the Dog** · 02-11-2011, 01:10 PM

If you've still got them in a year or so, I'll take them.

**DrAndy** · 02-11-2011, 02:35 PM

Ok Marmite, I will write your name on them plus 2012 November

unless some other bargain hunter wants them first!!

**DrAndy** · 08-11-2011, 10:32 AM

only a few PMs and no takers, as yet

so you still have a chance to have lovely hot water for whatever you like

**Butterfly** · 08-11-2011, 11:47 AM

do you include free installation ?

how much you give us if we take them

**roger77** · 08-11-2011, 12:13 PM

How much for the little one.

**DrAndy** · 08-11-2011, 01:52 PM

have a look at it

that one is set up on a stand, and has the magnesium rods in place, ready to go

B10,000 would get me my money back

sabaii sabaii · 08-11-2011, 02:11 PM

Have you tried putting 'em on Craigslist ?

**Butterfly** · 08-11-2011, 02:51 PM

I bid 2,000 THB

**DrAndy** · 08-11-2011, 03:16 PM

Originally Posted by sabaii sabaii

Have you tried putting 'em on Craigslist ?

no, I thought that was full of perverts

OK I will then

Originally Posted by Butterfly

I bid 2,000 THB

nobody would give you a cold water soapy for that, BF, never mind a hot one

sabaii sabaii · 08-11-2011, 03:30 PM

Thrown in a hairy arsed plumber to install it, and Butterfly would be up Chiang Mai in a flash

**DrAndy** · 09-11-2011, 08:39 AM

prob true

anyway, I have decided only to sell to a nice person, so that rules him out

**GuttaPercha** · 09-11-2011, 02:20 PM

There seems to be a lot of confusion here...

Broadly speaking there are two types of Solar HWS.
(1) Mains Pressure units which are designed to withstand town water pressure (or pressure pump),
and (2) Low Pressure units, which need a header tank (with float valve, etc) mounted above the unit to reduce the mains pressure, but still provide sufficient head..

Mains pressure units are normally more expensive due to their stronger construction, but have the advantage that your shower gets high pressure. To save cost, mains pressure units often use a steel tank (with a vitreous glass coating), unfortunately a tiny pinhole in the glass will cause corrosion and rapid failure.

The low pressure ones tend to last longer, but have the disadvantage that the shower pressure is much lower. You must use large diameter pipe for low pressure units.

Many HWS use a "sacrificial Anode" to prevent corrosion. The particular Anode must be matched to your water type. There are different Anodes for different water hardness. And the Anodes need to be replaced periodically.

All of them need an electric booster for when it is overcast for long periods. There are also wood and gas based boosters available.

You could mount either type at ground level, but it is better to mount them at roof level where they are out of harms way and get better sunlight.

I was puzzled re the "pump on the output" comment. You cannot put a pump on the outlet of a HWS. It makes no sense at all. If its a low pressure unit, you put the pump on the input and use a header tank to regulate the pressure.

**Thetyim** · 09-11-2011, 02:53 PM

Originally Posted by GuttaPercha

(2) Low Pressure units, which need a header tank (with float valve, etc) mounted above the unit to reduce the mains pressure, but still provide sufficient head..

So how much pressure/head can you apply to it?
8 metres OK ?

**Butterfly** · 09-11-2011, 04:17 PM

Originally Posted by DrAndy

prob true

anyway, I have decided only to sell to a nice person, so that rules him out

for 2,000 THB I can be a very nice person

**DrAndy** · 10-11-2011, 07:34 AM

Originally Posted by GuttaPercha

I was puzzled re the "pump on the output" comment. You cannot put a pump on the outlet of a HWS. It makes no sense at all. If its a low pressure unit, you put the pump on the input and use a header tank to regulate the pressure.

I put a pump on the outlet of the unit, no problem. It takes the water and can pump it up into the house; unfortunately, the pump did not like the water so hot and collapsed

so no confusion, but thanks for your post making things clear

Originally Posted by Thetyim

So how much pressure/head can you apply to it? 8 metres OK ?

the little header tank is screwed onto the top of the unit and just feeds water in as it is used

**benlovesnuk** · 10-11-2011, 10:41 AM

What about a closed system with separate tank, pump, electric back up and solar heater?

Surely this is the best system. Using the round tubes solar heaters?

It makes sense about the pump, because then you dont need to worry about hot water, if i get this system i will ask if i can add mutiple heating points for different areas sufficient for the persons usage and then i might think of buying one.

If not good luck selling to these cronies!

**DrAndy** · 10-11-2011, 11:14 AM

a closed system? what you have is the cold feed to the small header tank, which just refills the unit when hot water is taken out

the hot water can go to all the different outlets needed, by gravity normally. As I said, if you get a special pump suitable for hot (to 80C) water, then you can pump the hot water all over

they have an electric back up built in usually, for those cloudy days

**DrAndy** · 22-11-2011, 03:07 PM

update: the small solar water heater has been sold (bargain price)

the large is still available although I have been thinking that, if I could get it to the top of my shophouse it would work well there

anyway, B15k to anyone interested

**nedwalk** · 23-11-2011, 05:19 AM

very cheap ..DR A..and those tube systems are great..i was touting them in ozzie..setting up at the local shows and such, i did however break a few tubes , they are fragile compared to the 'panel' systems

Thread: Gravity type solar heaters

Thread Tools

Display

Solar water heating

Thread Information

Users Browsing this Thread

Posting Permissions