We're considering putting some frost potection heaters in a 12 metre
boat, it's a pretty well insulated steel boat and a 5kW oil central
heating system easily makes it uncomfortably hot without being turned
up high. (not very scientific/accurate but it goves some idea).

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.

--
Chris Green

On Nov 26, 12:10*pm, wrote:

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? *The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.

Tiny, tiny. Use heating tape directly on the pipes and under their
insulation.

Use rubbery closed-cell insulation, armaflex IIRC (not the open-cell
foam stuff which can absorb moisture and thus freeze).

Most important thing then is to eliminate draughts, try to partition
the area being frost-heated.

ET05 is a good digital frost thermostat, but quite expensive this time
of year (£22-24)... wait, TLC Direct have them on special offer right
now (£13 or something like that).

On 26/11/2010 in message
wrote:

We're considering putting some frost potection heaters in a 12 metre
boat, it's a pretty well insulated steel boat and a 5kW oil central
heating system easily makes it uncomfortably hot without being turned
up high. (not very scientific/accurate but it goves some idea).

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.

Before my Broom European became a victim of divorce I put 2 of the tubular
greenhouse heaters in the engine space run off a frost stat and that
worked fine.

--
Jeff Gaines Wiltshire UK
There are 10 types of people in the world, those who do binary and those
who don't.

Jeff Gaines wrote:
On 26/11/2010 in message
wrote:

We're considering putting some frost potection heaters in a 12 metre
boat, it's a pretty well insulated steel boat and a 5kW oil central
heating system easily makes it uncomfortably hot without being turned
up high. (not very scientific/accurate but it goves some idea).

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.

Before my Broom European became a victim of divorce I put 2 of the tubular
greenhouse heaters in the engine space run off a frost stat and that
worked fine.

How big were they? From CPC 2ft long is 80 watts and 4ft ling is 180 watts.

--
Chris Green

On 26/11/2010 in message
wrote:

How big were they? From CPC 2ft long is 80 watts and 4ft ling is 180
watts.

From memory 4' - definitely longer than 2'.

--
Jeff Gaines Wiltshire UK
That's an amazing invention but who would ever want to use one of them?
(President Hayes speaking to Alexander Graham Bell on the invention of the
telephone)

Jeff Gaines wrote:
On 26/11/2010 in message
wrote:

How big were they? From CPC 2ft long is 80 watts and 4ft ling is 180
watts.

From memory 4' - definitely longer than 2'.

OK, thanks (and to all the other contributions here).

--
Chris Green

On Nov 26, 12:10*pm, wrote:
We're considering putting some frost potection heaters in a 12 metre
boat, it's a pretty well insulated steel boat and a 5kW oil central
heating system easily makes it uncomfortably hot without being turned
up high. (not very scientific/accurate but it goves some idea).

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? *The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.

--
Chris Green

The best form of frost protection is to drain down. But you have to
make sure all the water is drained and all taps and valves opened.
The pipe work normally has to be installed with this in mind.

harry wrote:
On Nov 26, 12:10Â*pm, wrote:
We're considering putting some frost potection heaters in a 12 metre
boat, it's a pretty well insulated steel boat and a 5kW oil central
heating system easily makes it uncomfortably hot without being turned
up high. (not very scientific/accurate but it goves some idea).

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? Â*The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.

--
Chris Green

The best form of frost protection is to drain down. But you have to
make sure all the water is drained and all taps and valves opened.
The pipe work normally has to be installed with this in mind.

Well, possibly, but the boat is new (to us) and so I haven't a really
good idea yet where there may be water that can freeze. In addition
we're aiming to use/visit the boat occasionally all through the year
so total drain down won't be very convenient.

--
Chris Green

wrote:

We're considering putting some frost potection heaters in a 12 metre
boat, it's a pretty well insulated steel boat and a 5kW oil central
heating system easily makes it uncomfortably hot without being turned
up high. (not very scientific/accurate but it goves some idea).

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.

Difficult to say. You would need more when the outside temperature
is seriously cold than when it's merely just below freezing.

I use a 200W tubular heater on permanently, plus a cheap 240W convector
with a thermostat in it, in a 10m uninsulated GRP boat.

That's with the boat ashore, of course. Were it afloat, it might get
the odd bit of light deck frost, but the interior would not get cold
enough to freeze anything.

wrote:
We're considering putting some frost potection heaters in a 12 metre
boat, it's a pretty well insulated steel boat and a 5kW oil central
heating system easily makes it uncomfortably hot without being turned
up high. (not very scientific/accurate but it goves some idea).

Can anyone offer any ideas of what size electric heater(s) would be
necessary to keep the interior above freezing? The engine is frost
protected (anti-freeze in coolant) but there is other cold water
pipework to the galley and loo which would be damaged if it froze.


probavly 50-100W or less.

If 5KW is uncomfortably warm - say 25C and its -5 outside, then 1KW will
get you to 1C.

But whole house can be heated on 5Kw so I doubt you would neeed that
for just a boat.

Best to have a lot of heat and a frost stat.