Solarhart/Solar Water Heating

[Kelena]

On the other side of the island, there is a lot of praise for the Solarhart hot water heaters. They go on the roof and heat water using the sun. I was wondering if any of you have alternative water-heating or Paloma, on catchment, and if you have any thoughts on that.

Is there enough sun for Solarhart? Potential for rust?

[gtill]

The Solarhart is a real classic on Oahu. It doesn't need a pump to circulate till you need flow below, in which time it goes to full line pressure for feed. All the function of a ground tank. You need a strong roof for about 40gals. They are very visible, but very reliable.

[jerry]

We have solar hot water and it works great. The only problem is that there is no anti-scald valve at the water can get very hot.

The systems are sized according to the amount of average sun hours in your area. A system in Puna will usually have two panels, a system in Kona one. We have an 80 gallon tank and a passive system.

A passive system has the storage tank on the roof and sits above the solar collectors. By convection the hot water rises and the cold sinks generating the necessary circulation to keep the water hot.

It only takes a few hours of moderate sun to heat it up and three or four really gray days to run out of hot water. There is a back up electric element in the tank but we keep it off most of the time.

The other common type of system is considered an electric (or gas) water heater with solar backup. You have a larger than normal hot water tank at ground level and solar collectors on the roof. A small pump on the hot water tank circulates the water though the collectors. There is a thermostat on the pump to turn it off at night and when the water is hot enough.

I like the passive systems best--fewer parts, less electric usage.

Jerry
Art and Orchids B&B
http://www.artandorchids.com

[janeadams]

We have a solarhart, and are very happy with it. It's only when we've had solid cloudy days all in a row that we have to use the gas flash heater. Being off-grid, it's perfect because of its lack of a pump. We have 2 panels, and all the hot water we need! Go for it!

Jane

[macuu222]

Even cheaper...just put a tank in your back yard and let the sun heat the tank for hot water. You may be restricted to the sunny daytime for hot water...but if your retired like me....it's not a problem.

[StillHope]

Checked the Solahart website.There are 3 types of the device available.What type do you guys have and how much does it cost?
The company located in Australia.I typed a couple zip codes-no result.I assume,there is a dealer on BI.Any information would be appreciated.Thank you in advance.

[Guest]

quote:

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Originally posted by StillHope

Checked the Solahart website.There are 3 types of the device available.What type do you guys have and how much does it cost?
The company located in Australia.I typed a couple zip codes-no result.I assume,there is a dealer on BI.Any information would be appreciated.Thank you in advance.

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You can get a direct quote from a professional here

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Lower your expectations and be ready for anything.

[dirk1609]

We have a solarhart and really like it except for the fact that it cant automaticaly shut itself off. For example when we go on vacation we have to cover the solar panel so it doesnt over heat the water, release the preasure, and send scalding hot water down our roof and into the plastic gutters which I assume would pretty much melt. That is our only complaint, but it is kind of a big one. I was pretty stuned when we were told that this was an issue with a 2 year old system. You would think it would have a shut of once the water reached a certin temp.

[Kelena]

Wow -- that is a pretty important complaint -- it never shuts off and can spew scalding hot water if left unattended. The lack of a "scald" protector seems pretty important, too, although I can't help but imagine there is some fix for that.

And so, you have to get up the roof and cover the thing to prevent it from getting the water too hot. Hmm.....maybe a Paloma would be better, although I seem to recall from a previous thread that those don't work on catchment too well.

[Rob Tucker]

I experienced those unexpected rains of scalding water a few times. Killed the lawn were the water fell and I considered it quite dangerous. The cure, in my opinion, is to have a carefully selected pressure relief valve and then pipe it with a good capacity copper pipe down to the ground at a safe location or small drywell.

Some poorly done installation simply add the pressure relief valve on the roof and when it blows theres a dangerous cascade of very, very hot water.