Solar Collector Build DIY

REXXIBOY

Member
May 11, 2020
9
Long Beach California
I'm planning on putting a solar collector heating setup for the first time. The roof where I want the solar collector is almost flat. It is facing west as seen below. My equipment is in the south side. I have a few questions below regarding the placement of air relief valve and also the design etc. I was looking at Swimjoy and Heliocol because there ease of installation.

1. I've seen some solar installation where the relief valve is at the top , by the return side. But I also see some install it in the feed side, almost close to the roof. I'm wondering what is best..

2. It you look closely, I have added a dedicated return line instead of some designs where they just add it at the other end of the collectors, even manuals show this type of design which confuses me. This is one of those big question I have at this time.

The current design I have is from this website. I'm also planning to get the same type of valves and diverter they use on their installations.

My current collector is no where closer to 50% of my area to heat, but I wanted to start with 4-5 panels and perhaps add 4-5 more later.
max is 9 for my roof and per Swimjoy specifications for a 4x10.5 collector.

1589242955981.png

Pool Size Kidney Shape Size.JPG
 
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mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,584
Pleasanton, CA
1. I've seen some solar installation where the relief valve is at the top , by the return side. But I also see some install it in the feed side, almost close to the roof. I'm wondering what is best..
The supply side will give you more head room for pressure to keep the VRV closed. This is especially useful for VS pumps running at lower RPM. Also, it can be useful for your situation where you have a dedicated return where the head loss can be lower than in a traditional installation. In some installations, they will drop the VRV to about 6' above the equipment so the pump can run at very low speeds.

2. It you look closely, I have added a dedicated return line instead of some designs where they just add it at the other end of the collectors, even manuals show this type of design which confuses me. This is one of those big question I have at this time.
Most installations plumb the solar return into the existing pad plumbing rather than having a separate return. You can do it either way but by having a separate return, it lowers the head loss in the plumbing which means there is less pressure at the VRV to keep it closed and less head room if you want to use lower RPM on a VS pump. This can be mitigated by using a smaller return eyeball for solar.
 

REXXIBOY

Member
May 11, 2020
9
Long Beach California
Thanks Mark!

With regards to
#1. I really don't have VS pump at the moment and probably have no plans for VS pump unless it really is required for Solar Collector installation. If the VRV it is beneficial for a dedicated return line then I can probably put the VRV 6 feet above the equipment. Sorry to sound stupid, is there an instance where you actually have 2 VRV? 1 at the return side and 1 at the supply side?

#2. This is a great insight. This really locks my plan. I will definitely have a separate return.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,584
Pleasanton, CA
No you don't want/need 2 VRVs. You only need to break the vacuum at one location.

I didn't mean to encourage the use of a separate return. I think you are better off using one set of returns for both the pool and solar. In my mind, there is no real benefit for having a separate return for just solar. Since it sounds like you won't be using a VS, the lower head loss actually means higher energy costs for single speed pumps although not much.
 

REXXIBOY

Member
May 11, 2020
9
Long Beach California
No you don't want/need 2 VRVs. You only need to break the vacuum at one location.

I didn't mean to encourage the use of a separate return. I think you are better off using one set of returns for both the pool and solar. In my mind, there is no real benefit for having a separate return for just solar. Since it sounds like you won't be using a VS, the lower head loss actually means higher energy costs for single speed pumps although not much.

Sorry for the confusion Mark, I think I misunderstood the word "separate return" , What I was actually talking about was 2 different designs of return, Some designs have longer returns versus shorter. I've always wonder why. But, what I've seen on other design was that the supply side has to be push farther, but the return is shorter distance as seen on 2nd image below.



SOLAR Collector RETURN TYPE A.JPG
SOLAR Collector RETURN TYPE B.JPG
 

REXXIBOY

Member
May 11, 2020
9
Long Beach California
Here is another design I mention similar the image I sent above. It almost feel like different contractors have different strokes. Perhaps this has to do with the roof pitch, I have flat roof.
1589329952982.png

versus Design that I'm originally planing.


1589330263270.png
 

REXXIBOY

Member
May 11, 2020
9
Long Beach California
You should look into a Pentair/Hayward solar controller, they really help maximize the benefit of solar.
Oh, most definitely, There are several brands out there, but it looks Pentaire solartouch is a candidate for me. I'm planning to this in phases. I will add the controller eventually, I'm getting those Pentaire diverters and will add actuators to them.
 

norcalpool1

Silver Supporter
Sep 16, 2017
85
Silicon Valley,CA
Yup, If I understand correctly 15k is really low correct? I think my volume is more around 22-24k.
My pool is smaller, but I measured the volume when I filled it to be around 13Kgal-14Kgal. My home is closer to the bay and is often windy and not as hot as the interior SFO bay area. I have five panels on the south-facing roof and the heating doesn't seem sufficient. If there were more space, I would put two more heater panels.
 

REXXIBOY

Member
May 11, 2020
9
Long Beach California
Hello all. I finally got most of my 2, 3 way valves and also a Hayward Solar Controller. I have a question for any one that lives in Southern California.

1. Is it mandatory to have the 3 way valve with the drain hole? I live in Long Beach and I'm just thinking if this draining is necessary every night. I got the Pentair 3 way valve for $48 and I just realize for freeze protection, another model comes with a special drain hole for $80.

Pentair 263028 2 In. - 2.5 In. 3 Way Pentair Compool Valve
with NO DRAIN HOLE.
1590176383714.png


I can get this part separately for $50-$60
3-Way Solar drain down Diverter Assembly
1590176281683.png
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,584
Pleasanton, CA
It is a good idea to have the panels drain when the pump shuts off. If it doesn't drain, water could possibly remain in the panels while the sun heats it up to very high temperatures softening the panels and/or piping allowing for them to collapse.

As a minimum, one should drill a small hole in the valve to allow for draining. Some installers will do this. However, this short cut will allow the panels to fill with water when the valve is off and pump is on. Ideally, it should be unidirectional like in a solar valve.
 

REXXIBOY

Member
May 11, 2020
9
Long Beach California
Finally finish the valve setup. My pool guy tells me that out of 100 clients he takes care off, only 3 have solar pool heating. He says solar collects or cause algae? Shocking to know because I'm in southern california. I just want to extend my swimming season not heat the pool in winter lol.
I do not do my own chemical so that is why I have a service. I have it on bypass until I have ordered enough materials for the roof and ordering solar pool heating system below.
I have a solar controller from
Going for 5 panels for starters.

Current setup now
IMG_20200524_165001.jpg
 

AllenA

Silver Supporter
Bronze Supporter
May 1, 2011
83
Scottsdale, AZ
Hey Rex,
How's your build going? Will you build or purchase the panels? If built, what material will you use? PVC/PEX/CPVC? What size tees? I'm trying to see if feasible to build them. See my thread here:
Allen