The best solar water heaters are somewhat like choosing your holiday destination — it’s all about personal preference and what best matches your needs!
Many of you reading this have decided it’s time to go solar with your household water heating; you may be wondering what the best systems on the market may be.
This all depends on brand preference, system design, and needs, such as how much hot water you need.
This article looks at seven of the best solar water heaters in the United States.
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Table of Contents
How Does A Solar Water Heater Work?
Mechanism Of Action
The basics of how a solar water heater works all start at the source – solar radiation.
The sun’s rays reach and heat (this is solar thermal energy) an absorbent surface that heats the fluid passing through strategically placed pipes. This fluid can be the water, returning to the tank until needed. In more complex systems, the fluid is a heat-transfer fluid that flows back to a heat exchanging mechanism and warms up the water.
Source: U.S. Energy Information Administration
While the basic concept remains the same, an array of technologies allow you to do this.
Related Reading: How much do water heaters cost in the U.S.?
Types of solar water heaters
There are two primary types of solar water heaters.
These are active or passive. Each has the following subtypes:
| Solar Water Heater Type | Subtypes |
|---|---|
| Active Solar Water Heater | Direct Circulation Indirect Circulation |
| Passive Solar Water Heater | Thermosyphon Integral Collector-Storage |
Active Solar Water Heaters
Direct Circulation
These are the best solar water heaters for warmer climates!
In these systems, cold water pumps from storage units to a collector (solar absorptive surface) when the sun is out and back into your home.
They generally work to maintain warmth by constantly recirculating the heated water and simply flushing the hot water down as it is used within your household.
Indirect Circulation
Source: Valentine Eastern Sierra Reserves
These are known as closed-loop water heaters. They heat water by pumping an anti-freeze heating fluid to the collector solar absorbing surfaces and back down into a heat exchanger.
The heat exchanger absorbs the transferred energy effectively because of the thermal conduction materials it is made of. These include copper (most popular), bronze, steel, and other metals.
Passive Solar Water Heaters
Thermosyphon
This type of system is very popular and works by storing water on your rooftop and allowing the water to flow through solar energy collection tubes. The hot water flows directly into your household plumbing system as you open the hot water faucets.
Integral Collector-Storage
The integral collector-storage system works similarly to the thermosyphons. However, in this case, the cold water first flows into a solar collector which works to heat it in an integrated box-like structure containing tanks and tubes.
After that, water flows into a conventional heater to ensure a constant source of hot water.
What Are The 7 Best Solar Water Heaters In The U.S.?
Now that you know what type of solar heaters there are and how they work, it’s time to take a closer look at the best solar water heaters for your household on the market today:
1. Sunbank 40 Gallon Solar Water Heater
- System type: passive
- General price: $2500
- Capacity: 40 gallons
- Collector: borosilicate & nickel-plated copper heat pipe collectors
- Working fluid: water
- System certification: SRCC OG-300
The Sunbank is one of the best solar water heaters on the market!
It is a reputable heating system that prides itself on easy installation, efficiency, and affordability. Moreover, it comes with a 10-year and one-year warranty on separate components.
One of the latest developments making this heater stand out is its stainless steel tank’s new and improved corrosion resistance.
It also utilizes nickel-plated copper heat pipes. But the best thing about this solar water heater — it can be used as a pre-heating function as an entirely independent system!
2. Duda 300L Solar Water Heater System
- System type: active
- General price: $3601,83
- Capacity: 80 gallons
- Collector: borosilicate glass and tri-metal coated glass
- Working fluid: inhibited propylene glycol
- System certification: SRCC OG-100
According to DudaDiesel, their Duda active solar water heater systems are one-of-a-kind in absorption efficiency, with a whopping 93-96% rate!
This system is the most popular type in North America and has the advantage of allowing you to store your hot water anywhere you please, as well as the option of gas assistance heating.
In other words, storage can be placed at quite a distance from the collectors that absorb the solar radiation, and seasonal changes won’t affect this either (unlike in most passive heater storage systems).
So, this heater might be the best solar water heater for your household, should you live in a seasonally dynamic environment.
3. HelioMaxx™ 80G Glycol Solar Hot Water Evacuated Tube Collector Kit
- System type: active
- General price: $5399,94
- Capacity: 80 gallons
- Collector: borosilicate glass
- Working fluid: inhibited propylene glycol
- System certification: SRCC OG-100
Looking for a solar heating system but still want the option of a backup electrical connection too?
Then Heliomaxx might prove to be the best option for you.
The residential solar kits are designed by highly trained engineers who have crafted a product ideally suited to the colder northern climate – infamous for bursting and breaking most solar water systems.
Even better, the company mentions that you can expect a 10-year performance warranty.
The patented parts of this performing piece allow for excellent results and compatibility for almost all retrofitting.
If you find yourself in the icy northern environment and perhaps have some existing structural components you would like to add; the Heliomaxx is simply perfect.
4. Heliodyne Cool Climate Water Heating System
- System type: active
- General price: $6070
- Capacity: 80 gallons
- Collector: Not defined
- Working fluid: glycol
- System certification: SRCC OG-100
The closed loop design of the Heliodyne Cool Climate water heating system is ideal if you’re looking for a system that offers protection from harsh cold and harsh water chemistry (such as very brackish water).
This product works in any home setup, and the heating fluid offers maximum durability.
According to the company, this system will pay itself off in a mere 4-8 years from the start of operation. So if you’re after a system with a relatively short payback period and a hardy one, this system is a great choice that won’t disappoint.
5. Stiebel Eltron SOLkit SB 300
- System type: active
- General price: $4659
- Capacity: 80 gallons
- Collector: Copper tubes
- Working fluid: glycol
- System certification: SRCC OG-100
If you are somebody who likes a product from a company with a long-standing reputation – Stiebel Eltron is for you.
This company has been actively producing energy products for over 40 years and is dedicated to being at the forefront of advanced water heating technology.
These are among the best solar water heaters for federal tax credits, with savings and returns of around 30%.
The price of this kit is in the middle range, so you need not worry about crazy costs for this level of quality.
6. SolPal Integrated Collector Storage System
- System type: passive
- General price: $3793.54
- Capacity: 51.5 gallons
- Collector: Copper, aluminum, glass
- Working fluid: water
- System certification: SRCC OG-300
The SolPal brand offers one of the best solar water heating systems today.
This brand is all about unique design, aesthetic integration into your home, and easy installation, and it comes with a cherry on top – a 5-year guarantee.
If you’re looking for a sleek design, aesthetic pleasure, and good quality, you have come across the perfect match.
And to top things off, the price is also more affordable.
7. EagleSun DBS-80-40 Drainback System
- System type: passive
- General price: $3590
- Capacity: 51.5 gallons
- Collector: Not defined
- Working fluid: Not defined
- System certification: SRCC OG-300
This product is a drain-back design prides itself on its excellent reliability and ability to overcome the most common solar water heating system failures.
A more straightforward design with fewer components means more efficiency and stability in this case.
If it’s consistency that you’re after but don’t find yourself particularly concerned about the smaller capacity, then the EagleSun makes the perfect addition to your house.
Related Reading: Heating Your Pool With Solar Panels
Final Thoughts
Choosing between the best solar water heaters is quite a challenge – they all offer unique selling points.
At the end of the day, it depends on the type of system – active or passive – you are looking for, the cost (although they all fall within close range), brand reputation, and volume.
If you’re after a smaller and simple design, the EagleSun is for you.
If it’s the long-standing brand reputation that you’re after, the Stiebel Eltron is for you.
The good news is there is quite a variety to choose from.
So take your time, and research, and you’ll soon find what you’re looking for.
If you want to share your thoughts or ask us a question, please feel free to reach out to us in the comments section below! Alternatively, visit our forum or follow us on Twitter!
