Solar water heater: Points to consider?
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praveen
Feb 18, 2009, 5:40:13 AM2/18/09
to construction
From: blrguy (Original Message) Sent: 2/8/2009 8:47 AM
Hello,
I am about the start the research on the solar water heaters for our
house & thought of asking the experts here for their inputs. I
couldn't find any consolidated information online & hence thought of
putting it togethe here for everyone's benefit.
I am adding some points which I have come across till now. Pl. correct
me and add additional considerations which go in selecting the right/
effective/economical solar heater for house use.
--------------------------------------------------------------------------------
Guidelines for selecting a solar water heater for domestic usage:
1. Size: For a home with 3-4 people, go for a 100-150Ltr version. If
with 5-6 people, preferably go for a 200 Ltr version.
- Upto 150ltr, it comes with a single panel. 200lt version comes with
2 panels
- With 2 panels, they say 1-2 hrs of sunlight is good to heat up the
water for usability
2. Outlet Pipe insulation
- The outlet / hot water distribution pipe need to be thoroughly
insulated.
- Options available: < pl. populate >
* Rubber/wool/Foam insulated pipe
* PUF insulated pipe
* GI Pipe with AC rope insulation & a covering PVC sleeve
* HDPE pipe with AC rope insulation? (Better?? experts comment)
* Copper tubes :P - Seen this abroad for all heating purposes
(valid option?)
- Decide on the type of insulation needed based on the distance you
need to transfer the hot water
- Size of the pipe matters. Go for a 1.25 inch sized pipe just like
how you would do it for normal overhead tank's distribution line so
that adequate presure is maintained
3. Tank type
- Inner tank : Stainless Steel (SS). Companies claim that they put SS
304 grade for this. <Pl. expand this further - what other grade tanks
are good?>
- Outer tank: There are different options & types. Coated, Painted,
Steel. All steel versions are expensive
- Frame type: support frame for the tank &
- Tank shape: (what is the implication here of differnt shapes &
sizes)
6. Collector: ETC or FPC
ETC - Evacuated Tube Collector
FPC - Flat Plate Collecter
FPC is the traditional model with a flat copper plate used for
collecting solar energy & transferring the heat to the water
circulating underneath it.
ETC is the newer models which you see in showrooms these days with
Glass tubes which have a heat pipe for absorbingn the sun light &
passing it to the water. The glass tubes are vaccumised so that there
is very minimal heat loss. So, in my opinion, ETC is a better heating
option "technically", but practically, needs to be debated here.
* Which heats up faster? -- <Experts, pl. add technical explanation>
* Which stays hot longer? -- <Experts, pl. add technical explanation>
* Which is economical to maintain & service? -- The ETC model comes
with glass tubes which may need to be replaced if broken. Since they
are vaccummised models, if one tube is broken, the system is non-
functional. Each tube costs 600rs or so is what is understood. In
general, other than cleaning the dust on the panels, there is no need
of any kind of maintenance for the solar heaters is my understanding.
Service requirements are very minimal.
5. Pressurised Systems:
What we usually see works on atmospheric pressure. There are pumped
versions available known as Forced Circulation System. The domestic
versions used in India are the passive ones.
7. Insulation type
Both the storage tank & the collector plate should be well insulated
to avoid thermal losses. Commonly used insulation is PUF (Polyurethane
foam)
< Add details on what should be considered>
8. Facing directions
Direct sunlight with no obstructions.
Panels facing southwards
Water inlet tank maintained at sufficient height - About 3-4 feet
above the collector panel & storage tank for proper circulation within
the collector area & the storage tank.
9. Installation & Servicability
* Installation: Usually done by the supplier & all costs towards
transport & installation is included in the quoted price
* Service: Check their service centre location. It better be in your
vicinity so that you can go & bring them when you need them.
* Prerequisites for installation:
- Pipe lengths for plumbing purposes around the solar panel :
extneding the water inlet, connecting to your outdistribution etc
- Insulation material - check with the solar guy if it is needed
- Additional points?
10. Pricing (approximate street price - including all taxes & charges,
transport & installation)
FPC
100L with all steel: range?
150L with all steel:
200L with all steel:
ETC:
100L:
150L:
200L:
See TOI's property supplement on fridays for current prices :)
11. Some good options (subjective)
Tata BP solar - Quite expensive, peace of mind?
Kamal/Anu/SunTechnics/... series of pvt players - ??
Selco - govt funded/NGO initiative ???
12. Combo options : Solar water heater + Photovoltaic cells?
Any good details that you know of for having solar lighting also set
up for the house?
Hello,
I am about the start the research on the solar water heaters for our
house & thought of asking the experts here for their inputs. I
couldn't find any consolidated information online & hence thought of
putting it togethe here for everyone's benefit.
I am adding some points which I have come across till now. Pl. correct
me and add additional considerations which go in selecting the right/
effective/economical solar heater for house use.
--------------------------------------------------------------------------------
Guidelines for selecting a solar water heater for domestic usage:
1. Size: For a home with 3-4 people, go for a 100-150Ltr version. If
with 5-6 people, preferably go for a 200 Ltr version.
- Upto 150ltr, it comes with a single panel. 200lt version comes with
2 panels
- With 2 panels, they say 1-2 hrs of sunlight is good to heat up the
water for usability
2. Outlet Pipe insulation
- The outlet / hot water distribution pipe need to be thoroughly
insulated.
- Options available: < pl. populate >
* Rubber/wool/Foam insulated pipe
* PUF insulated pipe
* GI Pipe with AC rope insulation & a covering PVC sleeve
* HDPE pipe with AC rope insulation? (Better?? experts comment)
* Copper tubes :P - Seen this abroad for all heating purposes
(valid option?)
- Decide on the type of insulation needed based on the distance you
need to transfer the hot water
- Size of the pipe matters. Go for a 1.25 inch sized pipe just like
how you would do it for normal overhead tank's distribution line so
that adequate presure is maintained
3. Tank type
- Inner tank : Stainless Steel (SS). Companies claim that they put SS
304 grade for this. <Pl. expand this further - what other grade tanks
are good?>
- Outer tank: There are different options & types. Coated, Painted,
Steel. All steel versions are expensive
- Frame type: support frame for the tank &
- Tank shape: (what is the implication here of differnt shapes &
sizes)
6. Collector: ETC or FPC
ETC - Evacuated Tube Collector
FPC - Flat Plate Collecter
FPC is the traditional model with a flat copper plate used for
collecting solar energy & transferring the heat to the water
circulating underneath it.
ETC is the newer models which you see in showrooms these days with
Glass tubes which have a heat pipe for absorbingn the sun light &
passing it to the water. The glass tubes are vaccumised so that there
is very minimal heat loss. So, in my opinion, ETC is a better heating
option "technically", but practically, needs to be debated here.
* Which heats up faster? -- <Experts, pl. add technical explanation>
* Which stays hot longer? -- <Experts, pl. add technical explanation>
* Which is economical to maintain & service? -- The ETC model comes
with glass tubes which may need to be replaced if broken. Since they
are vaccummised models, if one tube is broken, the system is non-
functional. Each tube costs 600rs or so is what is understood. In
general, other than cleaning the dust on the panels, there is no need
of any kind of maintenance for the solar heaters is my understanding.
Service requirements are very minimal.
5. Pressurised Systems:
What we usually see works on atmospheric pressure. There are pumped
versions available known as Forced Circulation System. The domestic
versions used in India are the passive ones.
7. Insulation type
Both the storage tank & the collector plate should be well insulated
to avoid thermal losses. Commonly used insulation is PUF (Polyurethane
foam)
< Add details on what should be considered>
8. Facing directions
Direct sunlight with no obstructions.
Panels facing southwards
Water inlet tank maintained at sufficient height - About 3-4 feet
above the collector panel & storage tank for proper circulation within
the collector area & the storage tank.
9. Installation & Servicability
* Installation: Usually done by the supplier & all costs towards
transport & installation is included in the quoted price
* Service: Check their service centre location. It better be in your
vicinity so that you can go & bring them when you need them.
* Prerequisites for installation:
- Pipe lengths for plumbing purposes around the solar panel :
extneding the water inlet, connecting to your outdistribution etc
- Insulation material - check with the solar guy if it is needed
- Additional points?
10. Pricing (approximate street price - including all taxes & charges,
transport & installation)
FPC
100L with all steel: range?
150L with all steel:
200L with all steel:
ETC:
100L:
150L:
200L:
See TOI's property supplement on fridays for current prices :)
11. Some good options (subjective)
Tata BP solar - Quite expensive, peace of mind?
Kamal/Anu/SunTechnics/... series of pvt players - ??
Selco - govt funded/NGO initiative ???
12. Combo options : Solar water heater + Photovoltaic cells?
Any good details that you know of for having solar lighting also set
up for the house?
praveen
Feb 18, 2009, 5:40:33 AM2/18/09
to construction
From: blrguy Sent: 2/8/2009 8:49 AM
Calling all experts to pitch in with their inputs so that I can update
the main post with a consolidated view for every1s benefit :)
Calling all experts to pitch in with their inputs so that I can update
the main post with a consolidated view for every1s benefit :)
praveen
Feb 18, 2009, 5:40:44 AM2/18/09
to construction
From: tvsh Sent: 2/9/2009 2:12 AM
I am not aware of the models available in india. All the ones you
described are "direct circulation systems" in which water is
circulated through the collectors. One concern with these systems is
how well these would handle untreated borewell hardwater in the long
run. I read somewhere, indirect circulation systems are better if the
water used in untreated ground water (say a borewell). Not sure if
this is available in India yet.
Here is some useful information on solarwater heaters.
http://apps1.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=12850
I am not aware of the models available in india. All the ones you
described are "direct circulation systems" in which water is
circulated through the collectors. One concern with these systems is
how well these would handle untreated borewell hardwater in the long
run. I read somewhere, indirect circulation systems are better if the
water used in untreated ground water (say a borewell). Not sure if
this is available in India yet.
Here is some useful information on solarwater heaters.
http://apps1.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=12850
praveen
Feb 18, 2009, 5:40:54 AM2/18/09
to construction
From: sathyamkm Sent: 2/9/2009 12:51 PM
I tried solar lighting few years back and the systems available at
that time were not very attractice. (The battery needed, output for
the investment etc). Not sure if the situation has changed now. There
is lots of work and interest in USA and I will wait for next
generation of this technology.
Water heating is really worth considering.
I tried solar lighting few years back and the systems available at
that time were not very attractice. (The battery needed, output for
the investment etc). Not sure if the situation has changed now. There
is lots of work and interest in USA and I will wait for next
generation of this technology.
Water heating is really worth considering.
praveen
Feb 18, 2009, 5:41:21 AM2/18/09
to construction
From: namburi Sent: 2/16/2009 3:08 PM
Hi every one
Here are few points to consider while planning for solar points in
home.
1. Make sure every solar mail inlet point in toilet have facility to
pass through geyser or instant water heater. Since in winters you need
to leave at least one bucket of water to flush out the water in the
pipes and get hot water form solar tank.
2. Solar water heater is not the solution for instant water heating
requirements like in kitchen
The usage is very nominal of 4-8 liters for cooking or cleaning oil
vessels. So you should prefer instant heater .The size of instant
heater permits to fit below the kitchen counter.
3. If you are using showers like rain dance /shower panels you need
pressure booster pump. So make sure your plumbing lines takes that
pressure.
Regards
Ar.Praveen.N
Ardes Architects and Interior Designers
ardesar...@yahoo.co.in
Hi every one
Here are few points to consider while planning for solar points in
home.
1. Make sure every solar mail inlet point in toilet have facility to
pass through geyser or instant water heater. Since in winters you need
to leave at least one bucket of water to flush out the water in the
pipes and get hot water form solar tank.
2. Solar water heater is not the solution for instant water heating
requirements like in kitchen
The usage is very nominal of 4-8 liters for cooking or cleaning oil
vessels. So you should prefer instant heater .The size of instant
heater permits to fit below the kitchen counter.
3. If you are using showers like rain dance /shower panels you need
pressure booster pump. So make sure your plumbing lines takes that
pressure.
Regards
Ar.Praveen.N
Ardes Architects and Interior Designers
ardesar...@yahoo.co.in
praveen
Feb 19, 2009, 3:03:29 AM2/19/09
to construction
From: jaison_2007 Sent: 2/19/2009 12:16 PM
Hi,
Found some useful reviews in another forum,
http://www.mouthshut.com/review/V-Guard_Solar_Water_Heaters-145691-1.html
Hi,
Found some useful reviews in another forum,
http://www.mouthshut.com/review/V-Guard_Solar_Water_Heaters-145691-1.html
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