Calorifier vs Instant ?

[dewshi]

Which do people prefer and why: Calorifier or instant gas water heater?

 

Thanks

Edited December 16, 2020 by dewshi

[Tonka]

calorifer is heated free by waste from the engine

[Tony Brooks]

Calorifier plus gas boiler (or diesel boiler/stove). Lost too many eyebrows to instant gas heaters and they have a limited degree of water temperature rise so in really cold conditions the water can be not much more than  warm.

[tehmarks]

I've had a Paloma in the past and now only have an engine-heated calorifier (and 230V immersion heater, which is about as much use as a chocolate fireguard to a liveaboard continuous cruiser — but it's a relic of previous ownership). The instant heater was very convenient — but my old boat didn't have a shower (long story, don't ask). i only used hot water for the dishes and occasionally the laundry, and the bloody thing still went through gas relatively rapidly. And where it was installed made it very difficult to do anything sensible with the bathroom layout.

 

As someone who doesn't boat every day, the calorifier takes some thinking about in summer. I have a decent solar installation, and so there's not much need to run the engine in the summer months when not actually boating. And so I end up doing the dishes with kettle water and having cold showers. But my gas lasted five months even during lockdown when constantly home and making tea.

 

They both have their advantages and disavantages, and I think that if you were to choose between them, the correct answer woul depend on how you use the boat.

[Alan de Enfield]

38 minutes ago, dewshi said:

Which do people prefer and why: Calorifier or instant gas water heater?

 

Thanks

An 'instant' water heater is quite thirsty on gas - even when not in use, so it is always recommended that you turn off the pilot light, you then have to relight it every time you need hot water.

 

The second problem is that the output temperature is only 25 degrees C above the input temperature so if you have cold water in your tank at (say) 5 degrees in the winter your hot water is never going to get above 30 degrees C (not much more than 'luke warm')

 

A calorifier will hold the hot water for you at the engine water temperature (normally around 65 degrees C) so you get HOT water and can 'dilute' it with cold to get sufficient for a couple of 'hot' showers.

If you have a mains electric supply available (on your mooring) then you can use the immersion heater in the calorifier and get your water at 85+ degrees C , which gives much, much more hot water when diluted to 'comfortable temperatures'.

 

As as has been said, it depends on how you use the boat, or, even if you ever move the boat, as to which system will be best for you.

 

Maybe if you explain how you plan to use the boat you will get better answers taikored to your needs.

[cuthound]

I prefer a calorifier. Free hot water when cruising, reliable and no maintenance.

[dewshi]

@Alan de Enfield

 

30 minutes ago, Alan de Enfield said:

Maybe if you explain how you plan to use the boat you will get better answers taikored to your needs.

 

Thanks for this info, I'm currently looking at buying a boat with calorifer, so happy to hear it's potentially piping hot !!

 

I'll be continuous cruising, not anticipating mooring with a shoreline. So I guess I'll have to run the engine every day for hot water. Unless it's viable to use the immersion heater off the battery + inverter ??? I would guess this drains the battery in minutes.

 

Instant gas heaters remind me of my student bedsit days :--//

[Detling]

Calorifier free engine heat and with a webasto hot water as well. but webasto needs a to have a full load when running so needs rads on a bit when heating the calorifier in summer so we do that mid afternoon have doors and windows open and enjoy a glass or two outside. a well insulated calorifier heated to 65 C from the webasto is still warm enough for a shower 20 hours later.

[dewshi]

@tehmarks

 

Thanks for this ! I wondered how much use you get out of a gas bottle, and about managing the lack of hot water on demand from a calorifier. 

[Alan de Enfield]

8 minutes ago, dewshi said:

@Alan de Enfield

 

 

Thanks for this info, I'm currently looking at buying a boat with calorifer, so happy to hear it's potentially piping hot !!

 

I'll be continuous cruising, not anticipating mooring with a shoreline. So I guess I'll have to run the engine every day for hot water. Unless it's viable to use the immersion heater off the battery + inverter ??? I would guess this drains the battery in minutes.

 

Instant gas heaters remind me of my student bedsit days :--//

 

Fit a diesel fired Eberspacher and you have hot water on demand - along with central heating and a 'calorifier' full of hot water.

 

However, you will need to run your engine everyday for 2-4 hours to charge your batteries and you get 'free' hot water as a by product.

 

YOU DO KNOW about the need to charge your batteries EVERY day don't you ?

 

NEVER USE YOUR BATTERIES TO HEAT WATER.

[dewshi]

@Detling

 

6 minutes ago, Detling said:

a well insulated calorifier heated to 65 C from the webasto is still warm enough for a shower 20 hours later.

 

Wow! 

 

8 minutes ago, Detling said:

but webasto needs a to have a full load when running so needs rads on a bit when heating the calorifier in summer so we do that mid afternoon have doors and windows open and enjoy a glass or two outside. 

 

Really ?? I would be scared Greta finds out

[TheBiscuits]

2 minutes ago, Alan de Enfield said:

NEVER USE YOUR BATTERIES TO HEAT WATER.

 

And that's the voice of experience talking.

 

Just that one time, but it was enough!

[Alan de Enfield]

Just now, TheBiscuits said:

 

And that's the voice of experience talking.

 

Just that one time, but it was enough!

Memory like an elephant !!!!!!!!!!!11

 

 

Yes, you learn by your own mistakes - rarely from others mistakes.

[dewshi]

@Alan de Enfield

 

2 minutes ago, Alan de Enfield said:

However, you will need to run your engine everyday for 2-4 hours to charge your batteries and you get 'free' hot water as a by product.

 

Right! Probably get solar panels to help in summer.

 

5 minutes ago, Alan de Enfield said:

 

YOU DO KNOW about the need to charge your batteries EVERY day don't you ?

 

NEVER USE YOUR BATTERIES TO HEAT WATER.

 

Got it

[ditchcrawler]

1 hour ago, Alan de Enfield said:

 

 

 

However, you will need to run your engine everyday for 2-4 hours to charge your batteries and you get 'free' hot water as a by product.

 

YOU DO KNOW about the need to charge your batteries EVERY day don't you ?

 

NEVER USE YOUR BATTERIES TO HEAT WATER.

If you have sufficient solar in the summer time you don't need to run the engine and could use an immersion heater to use excess energy using a load dump system

[blackrose]

I prefer to have both - calorifier and instant gas. Plus more hot water options from the Webasto once I get that working and immersion heater from the mains.

 

Living afloat isn't about either/or, it's about having as many options as possible.

Edited December 16, 2020 by blackrose

[tehmarks]

5 hours ago, ditchcrawler said:

If you have sufficient solar in the summer time you don't need to run the engine and could use an immersion heater to use excess energy using a load dump system

Only my own perspective, and I haven't done the sums to back it up, but I wouldn't expect a moderate solar array (~400W) to support an average 230V immersion heater for very long.

 

You can get 12/24V immersions, but I've heard conflicting reports of their utility.

 

 

[sueb]

You don't need to run an engine every day without a solar system. A back boiler will also provide hot water.

[Alan de Enfield]

Just now, sueb said:

You don't need to run an engine every day without a solar system. A back boiler will also provide hot water.

You miss the point - without a solar system you need to run the engine every day to replace your electricity, you get the hot water as a 'bonus'.

[blackrose]

I don't have solar but I can go 4 or 5 days when I go away in summer without recharging the batteries. I put that down to the gas fridge. 

 

I'd like solar but it seems like it's a bit difficult to justify the expense at the moment. More equipment for equipment's sake.... The other thing is I'd need to remove a load of interior lining to route the cables from the roof to the batteries. External routing would be a botch.

[TheBiscuits]

2 minutes ago, blackrose said:

The other thing is I'd need to remove a load of interior lining to route the cables from the roof to the batteries. External routing would be a botch.

 

You could always make a hard top canopy for the back deck - sort of an electric generating bimini top ...

[blackrose]

1 minute ago, TheBiscuits said:

 

You could always make a hard top canopy for the back deck - sort of an electric generating bimini top ...

?

[tehmarks]

4 minutes ago, blackrose said:

The other thing is I'd need to remove a load of interior lining to route the cables from the roof to the batteries. External routing would be a botch.

Neat external routing is the only sensible approach for an already-lined boat, assuming you can't put the panels in the vague vicinity of the batteries (ie aft). Another option is to route the cables under the gunwales, so the only significant lining that needs to be removed is in the vicinity of the entry hole.

 

It seems stupid to eschew a wallet-saving and especially a planet-saving measure just because the results aren't visually pleasing enough for you. In the same category as buying a massive 4x4 for show when you don't need one, in my world.

[blackrose]

39 minutes ago, tehmarks said:

 

It seems stupid to eschew a wallet-saving and especially a planet-saving measure just because the results aren't visually pleasing enough for you. In the same category as buying a massive 4x4 for show when you don't need one, in my world.

 

Except that it wouldn't necessarily be wallet saving or planet saving in my case because when I go away I'm not running my engine every day for power. I'd still need to be hooked up to shore power at my mooring to run power hungry mains appliances like the washing machine, etc, and how much power is a mains battery charger on float actually using to power the boat's 12v system? Not very much.

 

I think what you're forgetting about is all the embedded energy that goes into the manufacture of solar panels and all the accoutrements that make up a solar system. If that equipment isn't used to generate power then the initial energy outlay of manufacture and cost of buying the equipment may well outweigh the energy payback. A bit like buying a massive 4x4 and not using it because you don't need one.

 

What might ostensibly be seen as "green" solutions aren't always the most environmentally sustainable. It really depends on the situation and on a lot of assumptions made from the outset.

Edited December 16, 2020 by blackrose

[blackrose]

21 minutes ago, tehmarks said:

Neat external routing is the only sensible approach for an already-lined boat, assuming you can't put the panels in the vague vicinity of the batteries (ie aft). Another option is to route the cables under the gunwales, so the only significant lining that needs to be removed is in the vicinity of the entry hole.

 

 

I'm not sure I understand. Are you suggesting routing the cables over the cabin side and drilling a hole through the gunwale? 

 

I could route the cables along the centre of the roof for a few feet and under one of the sliding hatch rails, but it's getting the cables around the edge of the roof overhang and down the stern bulkhead neatly to the deck and then through the deck that's the tricky bit.

 

Edited December 16, 2020 by blackrose