How many Ah per day for Chinapscher?

[Graham_Wright]

No, they dont usually have a thermostat. They just go n churning out heat at whatever setting you choose. They start at full heat during warmup. They do use a little more power at full belt obviously, as the fan is working harder. Some do have a preset temprature setting, but most people find it isnt sensitive enough to be worth bothering with. Mine just carries on churning out heat regardless! If you want a room thermostat facility you pay seven times the price and buy a 'proper' one from Eversplasher...

"At full belt" the pump will be dosing vigorously but its electrical consumption is low.

 

[B27]

"At full belt" the pump will be dosing vigorously but its electrical consumption is low.

At full whack the fans run faster though.

 

[B27]

What's a definition of small boat? Average size in the Caribbean is about 45ft. 'Small' isnt an SI unit

I try not to offend other people by calling their boat 'small'. Mostly!
Some people's 'big boat' is 23ft because their 'little boat' is a 14ft racing dinghy.
My 27ft is small to me, but suddenly it's a big lump among the line of 21ft weekenders.
I used occasionally to get to play on 80ft boats, a mate of mine used to be a superyot captain. So 45 or 50ft isn't big in the boasting stakes.
My ex-crew's son is Merchant Navy so all yachts are 'small boats'.

It's also about budget. Our boat is not a huge commitment.

 

[geem]

I try not to offend other people by calling their boat 'small'. Mostly!
Some people's 'big boat' is 23ft because their 'little boat' is a 14ft racing dinghy.
My 27ft is small to me, but suddenly it's a big lump among the line of 21ft weekenders.
I used occasionally to get to play on 80ft boats, a mate of mine used to be a superyot captain. So 45 or 50ft isn't big in the boasting stakes.
My ex-crew's son is Merchant Navy so all yachts are 'small boats'.

It's also about budget. Our boat is not a huge commitment.

If we are talking about how long a heater needs to run, it needs some context. A 2kw heater on a 27ft boat would be fine. A 5kw heater on a 45ft boat struggles. One will run on tick over. The other will be running hard

 

[LittleSister]

No, they dont usually have a thermostat. They just go n churning out heat at whatever setting you choose. They start at full heat during warmup. They do use a little more power at full belt obviously, as the fan is working harder. Some do have a preset temprature setting, but most people find it isnt sensitive enough to be worth bothering with. Mine just carries on churning out heat regardless! If you want a room thermostat facility you pay seven times the price and buy a 'proper' one from Eversplasher...

Mine must be different, it does have a temperature setting and the closer it gets to that setting, then the power output from the heater reduces and the fan speed reduces, so you can have it running at a low power and slow fan speed just to maintain the warmth.

Interesting. Mine does have a temprature setting, but it is so insensitive that its nto worth using: it willget far too hot befroe it switches off, and far too cold before itcomes back on again. Maybe something to do with where the sensor is fitted, but a with a t/stat worked pretty well - when it could be persuaded to stay lit, which wasnt too often!

The different eras of heater, across the different brands, have different means and methods for controlling temperature. My aged Eber (and some other brands of various ages) has just two heat settings. It starts on high, and can be turned manually to low (maybe half heat?). I have a simple thermostat in the cabin, but that merely turns the heater to off (with shutdown procedure) when the set temperature is reached, and restarts when the temperature falls. Downside of that is that it is very power hungry, as running the glow plug and start up uses a lot of amps.

More recent heaters I looked at a while ago could be connected to a thermostat, but were limited to one of two modes: either you could set it to switch by thermostat between low and high settings (in which case it will never turn off automatically, no matter how hot it got on the lower setting), or between on and off by thermostat (in which case switching between low & high could, like mine, only be done manually).

The latest heaters appear more sophisticated and have more continuous variability in heat output, rather than merely high and low settings (this seems implied, but not explicitly stated, by the manuals IIRC). The heater controls are also more sophisticated and can be set either to a particular heat output, or connected to a heat sensor and the heat output is varied torch and then maintain the set temperature.

Of course, how sensitive the switching is to temperature will depend partly on the thermostat itself (e.g the hysteresis set), and especially on the location of the sensor and how representative that is of the overall and used space, and whether it is or isn't too directly affected by the heater outlet(s). What temperature feels comfortable will, of course, depend on a range of factors, including radiation gains and losses, dampness and air movement.

In terms of overall consumption, switching off and restarting is very power hungry; the higher the temperature set the higher the consumption; the colder outside, the damper and the windier, the higher the consumption; the better insulated the boat the lower the consumption; the better ventilated the boat the higher the consumption (but reduced damp and less work for the fan); recirculating the heating air will reduce consumption but increase dampness (and hence not reduce it quite as much as you might assume); the bigger the boat, or the sections of boat actually heated, the higher the consumption (assuming the heater is capable of delivering the heat required), so closing a vent in a part of the boat where the heat isn't currently required will reduce it.

 

[Aja]

As per title really.
I have a generic diesel hot air heater, how many amp hours should I expect to use running it for e.g. a couple of hours in the evening and half an hour in the morning?

Does it not tell you in the instruction manual/ handbook?

 

[B27]

Does it not tell you in the instruction manual/ handbook?

I don't have the exact manual for the thing which came with my boat.
What I've found on line is a bit vague so real life data is reassuring.

Thanks to all those who've chipped in with real data.

 

[plumbob]

It's not supposed to have a main switch as that risks someone unwittingly switching it off before the cooldown sequence is done which best case might damage the unit and worst case could cause a fire.

I'm with that which is why I don't yet have one but as it's only ever me using it, I'll risk it.