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has anybody used ; https://www.commodoreaustralia.com.a...water-booster/ ?? seems kinda expensive for what it is , but good idea.... is there anything to do diy style ?, cheaper than $ 400....
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I agree that that is way overpriced, but they can charge that 'cause there isn't much else like it out there! Read through the page and manual; I get their point. They are doing two things at once: running the element at the maximum power point voltage, as well as giving a "switched AC" output to make the thermostat contacts work.
DIY style...well, apart from that controller, you'd better know electronics REALLY well. Working with that amount of power can be dangerous.
You can find lower voltage water heating elements available on eBay (and other places, I'm sure). Depends what kind of system you have or are thinking of, and what you're trying to do.
For that matter, I have wondered how feasible it would be to secure a water mat to the back of a solar panel, and collect heat that way--because the cooler solar panels run, the more efficiently they'll produce electricity--and you get free hot water, to boot. -
Looks like a B.S. scam to me.
Besides, why would you heat water that's already hot ?Comment
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It's an attempt to run a hot water heating element off of solar power with minimal conversion losses, plus a little "on/off" switched waveform to prevent an existing bimetallic thermostat from sticking shut. This replaces the power source of an existing electric hot water heater. Worth it? Probably not.Comment
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I say put an inverter on the panels and get a regular electric hot water heater. This way when the water is hot enough the heater turns off and you can send the excess to the poco for net metering or house usage.Comment
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If someone has net metering it makes a heck of lot more sense to install a heat pump hot water heater and heat water when they need it.Comment
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Heat pump hot water heaters don't pay in the north...but yes good idea in cooling dominated areas.Comment
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Back to basics:
If available, using nat. gas for domestic water heating is usually the most cost effective method.
HPWH methods can be difficult to get as cost effective as nat. gas in many areas of colder weather and/or less sunny climates.
In many warmer/sunny climates HPWH can probably compete w/nat. gas for cost fuel effectiveness but are more complicated, have higher installation costs and probably require more maint./servicing/baby sitting.
Using electric resistance for domestic water heating is easy to install, but very expensive compared to nat. gas.
PV to electric resistance heating is probably not cost effective compared to just about any other method of heating water, particularly if the PV is deliberately or ignorantly oversized and the excess generation is "stored" as heat in a domestic water tank.Comment
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That looks like the $250 tecluk board only more expensive. I wouldn't recommend for several technical reasons. This is one I do find interesting for about $200, I think from Poland. It appears to use the same technology I use to heat water with PV. It can be operated at a set fixed array voltage for use in parallel with a charge controller. Other mode is stand alone using MPPT. I rolled my own for less than $20 and it runs in parallel with my charge controllers gathering any excess power not used to charge my batteries. I use a 60V array of grid tie panels and common 120V 2.000W heating elements that can produce about 500W at the lower voltage. When the whole system costs less than $500, it is a quick payoff. Here is a video of the system that is on the market. It is computer narration, but far better than their prior video. https://www.youtube.com/watch?v=x1wqhZKJJscComment
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Here is an article about HPWHs. There are example from Vermont and Canada.
9 kW solar, 42kWh LFP storage. EV owner since 2012Comment
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I have a NYLE (built in Maine so they know cold) external HPWH and it is sad they left the home market. They used a different refrigerant that was a little more suitable for the colder climate. I have a couple of engineering studies on HPWH and just don't believe COP of much over 2. Refrigeration technology hasn't changed that much. It is all about the fine print and how far you want to stretch the truth.Comment
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No one questions that there is a temperature below which the heat pump portion of a HPWH wont work. If that is 30 days or 120 days out of the year that still leaves nine months or more days in which it can beat the pants off a resistive element. That is why a Hybrid like the Rheem or AO Smith can work in Northern climates..I agree a HPWH is no match for Natural Gas when available.
Also, to get back to the topic of this thread which is about heating hot water. A further point is that a HPWH has some degree of intelligence and would not waste energy to heat water that was already hot.LOLLast edited by Ampster; 08-02-2019, 10:08 AM.9 kW solar, 42kWh LFP storage. EV owner since 2012Comment
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And that from a trade publication with skin in the game.
Here is an article about HPWHs. There are example from Vermont and Canada.
Sometimes, and depending on the application, a HPWH can be cost effective in colder climates, but based on the operating principles of heat pumps, my educated opinion is the probability of getting a cost effective heat pump system in colder climates will be lower than getting a cost effective heat pump system in a warmer climate.
Do you have anything more to offer or add to the conversation beyond pointing to what others have to say/write ? What do you know of the subject ?Comment
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