Source of heat for hotwater

[Keith R]

Originally Posted by rotondon

electric shower heads no more no less dangerous than any other electrical appliance-been in use in central and south america for ions of years

Yes, and I have used them safely there many, many times.

HOWEVER, they tend to be energy-inefficient. Brazil, for example, has decided that they can reduce a big chunk of their energy consumption by replacing electric shower heads with solar water heaters. Some Brazilian cities have even passed laws requiring all new buildings to have solar water heating systems.

[adrianb]

Originally Posted by Ringo

We could not find any others. But as you know, stock and brand names will change. If we see something that will work, we don't get to picky.

Regards, Ringo

Thanks for the tip.

I just am not sure I want a no name chinese propane heater in my house.. Seems like there's a lot of ways for it to go wrong between carbon monoxide and gas leaks. The ones I saw didn't seem very high quality.

[eztime]

okay this is the simplest and easiest and most maintenance free way to go...a tankless propane hot water heater..I have installed a number of tankers hot water heaters..although they were natural gas heaters...they also come in propane..hot-water on-demand...with these particular units you do not need to store water and tank which eventually will cool down and takes awhile to heat back up..when you turn on the the hot water the unit automatically turns on and eats the water as you used.it.once you turn off the faucet the unit then turns itself off..as far as carbon dioxide is concerned you vent the gases outside not a big concern.

[JDJones]

The tankless propane heaters ain't bad.. as long as you don't live near the coastline.

If you do, they'll rust out in no time..(been there, done that)

Also, you'd be amazed how fast they consume a tank of LP gas.

[Ringo]

Originally Posted by JDJones

The tankless propane heaters ain't bad.. as long as you don't live near the coastline.

If you do, they'll rust out in no time..(been there, done that)

Also, you'd be amazed how fast they consume a tank of LP gas.

Just the facts from my experience.
I gave names and web sites for 2 LPG tankless water heaters.

I live on the Ocean, less then 100 meters from my house. Rust is a concern but we deal with it with no noticed rust on tanks or unit(s) after 2 years... LPG tanks and heater units are protected from direct wind driven salt air. Just had to change over a 50 lb LPG tank after 5 months by moving a valve to the second tank. Supplies hot water to the 2 bath sinks, kitchen sink and shower... and wife likes long and hot showers. No elec. needed for the heaters except for new ones that use 2 D sized batteries.

Regards, Ringo

[Ringo]

Oops, also hot water for the day housekeeper in her bath and cleaning.

Each can find what works best for themselves.

Regards, Ringo

[jer]

installed a gas tankless (taiwan model) two weeks ago.* needed a small pump to boost the tinaco water pressure.* so far so good.

[beeza]

Yes you're right beware of the trolls, there's plenty in these fora (is that the plural of forum?)

Everyone seems to be an engineer! What exactly is a maintenance engineer? It's another name for a technician. So let's get these qualifications into perspective.

In the field of engineering there are generally three trade levels. A mechanic, a technician and an engineer.

A mechanic maintains things by following procedures written in manuals and skill.

A technician repairs things by using manuals, diagnosis and skill.

An engineer builds things and writes the manuals.

Engineers are educated to degree level. They not only use formulae, they write them and derive from source.

So let's get back to what our esteemed and educated Skippy is trying to tell us with his considerable and well founded knowledge.

Dominican houses are plumbed with plastic piping and as a result it is almost impossible to get the water running through them at the same potential (another name for voltage) as earth.

In modern electrical systems a device called a Residual Circuit Current Detector RCCD is used. This device measures the amount of current going into the load and then measures the amount of current coming out of it, see Kirchoff's law for details. If at any time a current leakage occurs the RCCD would trip off in milliseconds. A current leakage is when either the supply current or returning current goes to ground. As there is no real grounding in Dominican houses this leaked current goes through the water, through YOU and then to ground. A lethal voltage is considered to be 50 volts AC or 120 volts DC. So its stands to reason that you potentially have TWICE the lethal voltage from our 110v electrical supply.

All for this current leakage to occur would be a faulty connection, a broken down insulation or a mechanical failure. Have you seen how Dominicans wire up houses here?

I'm not going to put it all down to Dominican workmanship either. These on-demand electric heaters have an electrical element that is constantly heating up then cooling down. This causes premature ageing and fatigue in metal. Inside these elements, the only thing insulating you from 110v AC is a 2mm sleeve of ceramic. As soon as this ceramic breaks down....you're dead! And who knows when that will happen, could be 40 years, could be more, could be less. But it's a when, not an if.

I haven't seen RCCDs for sale here in any of the ferreterias. I've spoken to a few Dominican electricians who have never heard of them. Even if they are available, it still needs a good, well bonded ground circuit for it to be effective.

So IMHO stay away from electric water heaters in this country.

By the way did I mention that I'm an engineer too! And the difference between a mechanical engineer and a civil engineer?

Mechanical engineers build weapons.

Civil engineers build targets!

[catcherintherye]

beeza, you must be a civil engineer because you just made yourself a target. Just kidding, of course.
However, your analysis of how electricity seeks ground through water is faulty, since water isn't necessarily a ground unless it is IN the ground. In other words, when water is stored in a plastic tinaco and passes through PVC pipes and PVC drains, it is not actually grounded at any time. Therefore it never is in a position to complete an electrical circuit, thus cutting the chances of electric shock from faulty electrical showerhead heaters considerably.
And that from neither a builder of weapons nor targets.

[beeza]

Catcherintheye, my analysis isn't faulty and you've helped explain why!

Just because something is in the ground it doesn't necessarily have the same potential as ground. So like you have now explained we now have an entire water system at a different potential to the rest of the house.

If you know about electrical theory you need a PD (potential difference) for current to flow, That's where the flow of electrons from a positively charged atom flow to a negatively charged one

Stand under a shower with a water system at a different charged potential to you and whatever you are standing and you will get a current flow. And some of that current flow will go through your heart!

Also don't forget you only need a PD of 50vac for it to kill you. With 110v you are starting with twice the lethal voltage, with 220v you have four and a half times!