Oven, Alarms and Fridge

[simplicity1987]

Hi,

 

Having recently taken the plunge to buy my first narrowboat, I am trying to do a new fit out and finding A LOT of steep learning curves to overcome. Please find other posts listed in this forum, with any helpful advice gratefully received.

 

Oven

As long as it is LPG adaptable and has the FSD protection am I right in thinking I can just buy a 'normal' gas oven for the boat? The only issue is how to convert the ignition from 240V mains to 12V. Any ideas?

 

Alarms

Cheap but reliable recommendations please (quite the heavy sleeper). Was going to fit a lpg gas (£10.00) http://www.ebay.co.uk/itm/838-1L-Kitchen-Warning-Alarm-LPG-Natural-Gas-Sensor-Detector-DC-12V-ONLY-/150933060239?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BIEW%252BFICS%252BUFI%26otn%3D21%26pmod%3D160908813237%26ps%3D54, smoke (£6.00) and carbon alarm http://www.thesafetysupplycompany.co.uk/p/4566878/Kidde-Carbon-Monoxide-Alarm---Digital-Readout---Battery-Operated-AAs-Included---KS-DCO.html?gclid=CLel0tGU3rYCFaTItAodnmYA2Q#.UXUdlaWBW5Q (£25.00) - is this going too cheap or will these suffice?

 

Fridge

Looking at a 12V but will have 240V split that would switch to 240V when plugged into mains. These are really expensive (£400-500)? Is this just the going rate for such a product. It seems anything thats' got 'boat' or 'marine' attached to the product has a heavy premium attached.

 

Hope to hear from some of you soon.

 

Happy Boating

 

Max

[Chalky]

Oven

As long as it is LPG adaptable and has the FSD protection am I right in thinking I can just buy a 'normal' gas oven for the boat? The only issue is how to convert the ignition from 240V mains to 12V. Any ideas?

 

As long as it meets the requirements of the Boat Safety Scheme you can fit what you like

 

http://www.boatsafetyscheme.org/

Edited April 22, 2013 by Chalky

[nicknorman]

Oven: assuming its not a fan oven, you could always use a match! Otherwise a small inverter would be needed - you could install it with a switch in the galley so its only on when you are cooking. Of course it is possible to install a 12v igniter system but that could be diddly and involve dismantling your new oven.

 

Yes a domestic oven with LPG jets and flame failure device should be OK, if perhaps on the large side for a boat (but we have one like that).

 

12v fridges are expensive but worth it - expensive I think just because its a relatively small market and the economies of scale are lacking. There is no need to have a 240v option - better to have a battery charger that keeps the 12 system topped up when on land line. Avoid the old multi-source (gas, 12v, mains) absorption type caravan fridges because they are very inefficient on 12v.

 

For a CO alarm I would go for one with a display, so you can monitor for any increase in CO level below that which actually triggered the alarm. Pay attention to the instructions about positioning the alarms.

Edited April 22, 2013 by nicknorman

[Chalky]

We have a 240V fridge with an inverter running off the batteries. We also have an auto switch over between the inverter and mains supply. Ideal for a holiday boat but not ideal for a live aboard since the current draw from the batteries is high unless you have a permanent land line (with a galvanic isolator or transformer). Not necessarily the best solution but it works for our use case.

[Jambo]

12v fridges are expensive but worth it - expensive I think just because its a relatively small market and the economies of scale are lacking. There is no need to have a 240v option - better to have a battery charger that keeps the 12 system topped up when on land line. Avoid the old multi-source (gas, 12v, mains) absorption type caravan fridges because they are very inefficient on 12v.

 

I'm interested to know if there's any actual consumption data for 12V fridges. We ended up plumping for an A+++ rated 240V under the counter fridge (no freezer box), partly because we only have 240V sockets in our boat, but mostly because its efficiency was so amazing.

 

The official figures put consumption at 64kWh per year which works out to be an average power draw of 7W. Naturally we need to run our inverter 24/7 to keep it cold but that operates at 90% efficiency so I'm not too fussed about that.

 

I'd be interested to know how many amps the best 12V fridges draw on average. Anyone know?

[simplicity1987]

Oven

"Use a match" - that's that issue solved then. I assume by just connecting the gas oven up to the lpg pipe and leaving the mains off the oven, the oven should still work fine without any issues - the mains would only be needed for the ignition and no other saftey features? Just for reference, this is the oven I am currently looking at buying:

http://www.idealkit.co.uk/products/beko-bdg582s-50cm-double-cavity-gas-cooker?utm_source=google-product-search

 

 

Fridge

Does this seem good value/the going rate for a decent 12V fridge then?

http://www.ebay.co.uk/itm/Shoreline-12v-24v-White-Fridge-Icebox-Boat-Caravan-Motorhome-RK131W-/271190733369

 

Also, just out of curiosity - from my understanding, quite an expensive system to fit, but does anyone have a solar panel that is connected up to just one of your domestic batteries, that is then solely responsible for powering the fridge freezer?

 

Thanks again

[BEngo]

<Snip>

 

Also, just out of curiosity - from my understanding, quite an expensive system to fit, but does anyone have a solar panel that is connected up to just one of your domestic batteries, that is then solely responsible for powering the fridge freezer?

 

Thanks again

The chemistry of batteries is such that it is best to have the fridge part discharge a large bank rather than have a smaller dedicated battery. A solar panel will deliver as much, if not more power into a large bank as it will into a smaller one, depending on your controller. The Smartgauge site has an explanation of why using a smaller battery just for the fridge is not a good idea- Mr Peukert is not on your side.

 

N

[bottle]

Oven: make sure the FSD (FFD) is on all burners.

 

Fridge; google is your friend have a search with the model number, price is in the ball park for a 12/24v fridge.

 

Curiosity: simple answer forget it. By all means have a solar panel (you may be surprised how big you need, to run the fridge especially in autumn, winter spring)

[Jambo]

Fridge

Does this seem good value/the going rate for a decent 12V fridge then?

http://www.ebay.co.uk/itm/Shoreline-12v-24v-White-Fridge-Icebox-Boat-Caravan-Motorhome-RK131W-/271190733369

 

Also, just out of curiosity - from my understanding, quite an expensive system to fit, but does anyone have a solar panel that is connected up to just one of your domestic batteries, that is then solely responsible for powering the fridge freezer?

 

Thanks again

 

That one costs slightly more than the A+++ rated 240V fridge that I bought and uses 2.4 times the electricity and is smaller (but this 12V one has an ice box which mine doesn't)

 

There are 240V fridges with ice boxes which are bigger, more efficient and cheaper than that 12V fridge here:

 

http://greenandeasy.co.uk/categories/liebherr-fridges.aspx

[Keeping Up]

I'm interested to know if there's any actual consumption data for 12V fridges. We ended up plumping for an A+++ rated 240V under the counter fridge (no freezer box), partly because we only have 240V sockets in our boat, but mostly because its efficiency was so amazing.

 

The official figures put consumption at 64kWh per year which works out to be an average power draw of 7W. Naturally we need to run our inverter 24/7 to keep it cold but that operates at 90% efficiency so I'm not too fussed about that.

 

I'd be interested to know how many amps the best 12V fridges draw on average. Anyone know?

 

Our Shoreline12v fridge (with icebox) consumes about 1.5 amps on average.

[Chalky]

I'm interested to know if there's any actual consumption data for 12V fridges. We ended up plumping for an A+++ rated 240V under the counter fridge (no freezer box), partly because we only have 240V sockets in our boat, but mostly because its efficiency was so amazing.

 

The official figures put consumption at 64kWh per year which works out to be an average power draw of 7W. Naturally we need to run our inverter 24/7 to keep it cold but that operates at 90% efficiency so I'm not too fussed about that.

 

I'd be interested to know how many amps the best 12V fridges draw on average. Anyone know?

 

If the fridge has a traditional control system then you can run it off a pseudo sine inverter. If it's an inverter controlled motor then you'll need a sine wave inverter to drive it. The inverter won't be 100% efficient - pseudo sine are more efficient than sine (transistor switching losses) so recon on 80% - 90% efficiency.

You'll also need to keep the inverter running whenever you run the fridge and this can draw anywhere between 500ma to 1A permanently just to keep the electronics running (quiescent current). Your inverter will have to be able to cope with a surge of several kW to start the motor so this implies a larger inverter with a higher quiescent current.

Factor these in and it's significantly worse than 7W.

[simplicity1987]

So, with the oven, as long as it meets regs, there would be no issue with simply not plugging in the ignition mains connection and just using matches to get the hobs and oven going? Is this safe or would the oven need to be connected to electricity for any other purpose?

 

"Just like the good ole days..."

[Jambo]

Fair points Chalky.

 

We have a Mastervolt Mass Combi 12/2000 and its specs suggest 90% efficiency and "< 9W DC consumption inverter at 230 V" so if I allocate all of that demand to the fridge (which isn't quite right as we have other AC demands) then we're looking at somewhere around 16W and 0.38kWh per day - comparable to the 12V linked to above.

 

Looking forward to installing the PV so that we can cover this and more!

[simplicity1987]

Also, which models, where and how many lpg gas alarms have you all fitted inside your boats?

[Chris Pink]

Just for reference, this is the oven I am currently looking at buying:

http://www.idealkit.co.uk/products/beko-bdg582s-50cm-double-cavity-gas-cooker?utm_source=google-product-search

LPG? Edited April 22, 2013 by Chris Pink

[simplicity1987]

LPG - Liquefied petroleum gas

[Chris Pink]

Thank you. I've lived on a boat for 25 years and I never realised.

[nicknorman]

So, with the oven, as long as it meets regs, there would be no issue with simply not plugging in the ignition mains connection and just using matches to get the hobs and oven going? Is this safe or would the oven need to be connected to electricity for any other purpose?

 

"Just like the good ole days..."

It's a cooker not an oven, but never mind! The flame failure devices are self- powered by thermocouple. So assuming the oven has no fan to cool the gap between oven and external surface, the only other thing you will lose is the oven light, useful to see how your latest bakery masterpiece is doing!

 

If it was me, If you are going to the trouble of fitting out a new kitchen I would fit a cheap small inverter to run these things. But I suppose you could just run some wiring to a suitable cupboard etc and see how it goes, adding a dedicated inverter later if it proves necessary.

 

Modern 12v fridges are pretty efficient. So are mains ones, but you need a reasonable sized inverter to deal with the compressor startup current and its not so much the efficiency as the fixed current taken by the inverter 24/7 that affects overall power efficiency. Unless of course you plan to have an inverter running all the time for other reasons. Having a fridge powered by an inverter also adds a layer of technical complexity and hence reduces reliability. You would have two things either of which going wrong would mean no ice for the G&T - disaster!

 

Solar panels are a good idea for live aboard but I see no point in seperating the battery banks other than for the engine starter

Edited April 22, 2013 by nicknorman

[simplicity1987]

Thanks nicknorman - good sound advice. I think a 12V fridge will keep it simple, so am going to stick with the option discussed. With regards to the cooker, I've phoned the store and the fella on the phone seems reluctant to offer any advice on the matter. 'Legal reasons' apparantly. From doing a bit of reading, it seems the hobs would be fine to light with a match, but the main cooker could be tricky as it has a shut off valve if the oven isn't being supplied with electricity.

 

Will probably end up buying a cheap invertor like this one (http://www.rockshore.uk.com/maypole-300w-power-inverter-12v230v-6822-p.asp) for the dake of £30.00, this seems like a decent option. I will find out the wattage needed, but would imagine the iginition starter wouldn't need much more than 3000 Watts Invertor as seen in link provided?

[simplicity1987]

*300 Watts

[Chris Pink]

 

LPG?

I see the answer to my question is 'it can be converted'. Shouldn't be difficult to source but might be.

Edited April 22, 2013 by Chris Pink

[simplicity1987]

I see the answer to my question is 'it can be converted'. Shouldn't be difficult to source but might be.

 

Most ovens nowadays are 'LPG adaptable' meaning you can either request the correct valves to be inserted, or you can buy a seperate LPG conversion kit - only costs around £10.00.

[Keeping Up]

Also any oven which is stated as suitable for installation in a flat, must meet the same flame failure requirements as one for installation on a boat.

[nicknorman]

I see the answer to my question is 'it can be converted'. Shouldn't be difficult to source but might be.

There's a fairly big market for domestic cookers to be supplied by calor gas etc, so I think a manufacturer making an appliance without that capability is limiting their market unnecessarily for the sake of some different jets. Worth checking though, of course.

 

*300 Watts

300W will be fine for oven light and ignition. I am surprised you say that mains is required for a gas valve for the oven, makes me think that perhaps there is a cooling fan? That inverter has a cooling fan, might be worth checking that it only runs when the inverter is getting hot, not all the time, otherwise it could be a bit irritating and of course increase fixed current drain. Edited April 22, 2013 by nicknorman

[Alan de Enfield]

. I am surprised you say that mains is required for a gas valve for the oven, .............

 

We have an LPG cooker (and rings) at home, this has a 220v controlled gas valve.

You cannot get a gas flow without the power switched on, and, there is a red 'escape button' by the door, so, if there is a problem you can hit the button on the way out and it cuts off the electricity and hence the gas supply.

 

Poblem is that when we have a power cut we dont have any gas either !!!

 

Sounds similar to that mentioned above.

Edited April 22, 2013 by Alan de Enfield