Where do I start with Solar heating

[NetComrade]

Capex:
Sanden 4K
Taco RMB 1K
Eco 11k $200
Pressure Pal MF200S $600
Heat Exchanger $150
Filter/Expansion tank $200
Manifolds x2 $300
Mixing Valves x2 $300
Misc Plumbing estimated ~1k
-------
Total: ~8K + labor

Solar heat exchangers/sensors/pumps TBD later

[NetComrade]

All,

I've followed up with a post on the heating forum on this

https://forum.heatinghelp.com/discussion/165372/sanden-ecocute-instant-heater-as-backup-radiant-design/p1?new=1

After doing some reading, I think I found a solution that will work.. here's a copy and paste of my last post

After reading the following..

https://www.bpa.gov/EE/Technology/EE-emerging-technologies/Projects-Reports-Archives/Pages/Combined-Space-and-Water-CO2-Heat-Pump-System-Performance-Research-.aspx

I decided to flip the Sanden to the DHW side of the heat exchanger.. Sanden really likes the water to be colder. I will need to filter water to minimize impact of well water to equipment.

The long paper basically validated my design (as it has been field tested with backup), and my new design now looks more like the design used in this study.

This will also allow me to pre-heat water for radiant use (but not DHW, although that could be figured out later, IMO), which would have been difficult if Sanden was on the 'heating' side of the plumbing.

Diagram is overly simplified, and will need additional plumbing details by a professional,.

20180319_122415_small.jpg

[monogram]

sorry to post it here as Admin haven't approve for new user like me yet.

my question is: can I connect 2 panel with different voltage in parallel?
Suntech STP250 - 20/Wd Specifications

[TABLE="border: 0, cellpadding: 0, cellspacing: 0"]
[TR]
[TD]STC[/TD]
[TD]STP250-20/Wd[/TD]
[/TR]
[TR]
[TD] [/TD]
[TD] [/TD]
[/TR]
[TR]
[TD]Maximum Power at STC (Pmax)[/TD]
[TD]250 W[/TD]
[/TR]
[TR]
[TD]Optimum Operating Voltage (Vmp)[/TD]
[TD]30.7 V[/TD]
[/TR]
[TR]
[TD]Optimum Operating Current (Imp)[/TD]
[TD]8.15 A[/TD]
[/TR]
[TR]
[TD]Open Circuit Voltage (Voc)[/TD]
[TD]37.4 V[/TD]
[/TR]
[TR]
[TD]Short Circuit Current (Isc)[/TD]
[TD]8.63 A[/TD]
[/TR]
[TR]
[TD]Module Efficiency[/TD]
[TD]15.4%[/TD]
[/TR]
[TR]
[TD]Operating Module Temperature[/TD]
[TD]-40

[Mike90250]

sorry to post it here as Admin haven't approve for new user like me yet.

my question is: can I connect 2 panel with different voltage in parallel?

Generally, yes, as long as they have Vmp spec within 10% of each other - you only listed one Vmp 30.7v