440: Lagoon 440 -- Need Input on Appliances

[james3]

yes this is what I was thinking about simply because the space is too small to include an insulation layer. Anyway fiberglass is an insulating material but I don't know if it's thick enough.

Have anyone took a look to the aerogel ASPEN AEROGELS ?? Nothing insulate like this (it came from the aerospace industry and insulate more than polyurethan so it should do the job in an enough thin layer )

[Dockhead]

Originally Posted by Cotemar

In NYC the winters are to cold for that system.
Just purchase a few of these portable oil heaters or go with a diesel furnace.

I disagree. A reverse cycle AC system can pump out a huge amount of heat, and it takes less amps of electricity for BTU than electrical resistance heating, at least down to a certain water temperature (probably lower than freezing). Just do the numbers. But you will get much greater efficiency with a water-cooled, purpose designed marine air conditioning system. This is a very worthwhile investment.

I think all your appliances prospects are realistic. I think you can live in perfect comfort in the NYC climate on a decent sizing cruising boat like yours. I say go for it. You will just need to keep enough heat pumping through to eliminate condensation, and some ventilation. But for that, I think reverse cycle AC is your best bet. Have fun; sounds like a great life.

[james3]

Originally Posted by Dockhead

I disagree. A reverse cycle AC system can pump out a huge amount of heat, and it takes less amps of electricity for BTU than electrical resistance heating, at least down to a certain water temperature (probably lower than freezing). Just do the numbers. But you will get much greater efficiency with a water-cooled, purpose designed marine air conditioning system. This is a very worthwhile investment.

I think all your appliances prospects are realistic. I think you can live in perfect comfort in the NYC climate on a decent sizing cruising boat like yours. I say go for it. You will just need to keep enough heat pumping through to eliminate condensation, and some ventilation. But for that, I think reverse cycle AC is your best bet. Have fun; sounds like a great life.

I'm sorry but I can't agree with you,
heat pump doesn't works fine with a really cold temperature outside (2- 3°C). An heat pump system work efficiently when the difference between outside and inside is not that much, differently they simply doesn't work.
here the heat pump cycle is explained https://en.wikipedia.org/wiki/Heat_p...geration_cycle
About what I got, the best heating system for a boat in a so low temperature is the diesel heating system (the same that Lagoon sells as optional).
The cheapest system is to buy some of these electric heaters

[MylesK1]

DotDun is right. Lagoon 440's, like most production boats nowadays, have no insulation. They're typically fiberglass on balsa wood with a layer of gelcoat over it. Most houses, on the other hand, have at least a layer of air between the outer walls and inner walls. Believe it or not but that air creates a thermos effect, even if it's not substantial.

Our plans are to use space heaters and wear socks. Reverse-cycle AC/Heaters shut off when the water is less than 40 degrees F (from what I hear).

[james3]

Originally Posted by MylesK1

DotDun is right. Lagoon 440's, like most production boats nowadays, have no insulation. They're typically fiberglass on balsa wood with a layer of gelcoat over it. Most houses, on the other hand, have at least a layer of air between the outer walls and inner walls. Believe it or not but that air creates a thermos effect, even if it's not substantial.

Our plans are to use space heaters and wear socks. Reverse-cycle AC/Heaters shut off when the water is less than 40 degrees F (from what I hear).

Yes an A/C reverse cycle heat pump simply doesn't work below certain outside air temperatures. Anyway don't forget that the ocean water in the winter is really cold (I live in Mediterranean and here is not that cold) take a look here Ocean Water Temperatures for New York - Current Results

so think that your hulls will be partially submerged into a 36-43 °F cold water into the winter period

[Dockhead]

Originally Posted by james3

I'm sorry but I can't agree with you,
heat pump doesn't works fine with a really cold temperature outside (2- 3°C). An heat pump system work efficiently when the difference between outside and inside is not that much, differently they simply doesn't work.
here the heat pump cycle is explained https://en.wikipedia.org/wiki/Heat_p...geration_cycle
About what I got, the best heating system for a boat in a so low temperature is the diesel heating system (the same that Lagoon sells as optional).
The cheapest system is to buy some of these electric heaters

Sorry, if you will read your own link carefully, you will see that the outside temperature has nothing to do with the efficiency of the cycle. It is the temperature of the heat exchange medium, not the outside temperature. In this case, it is sea water. So it can be -50 outside or +40, and it makes no difference at all. The amount of BTU's of heat produced depends purely on the temperature of the sea water.

The confusion comes from the fact that regular domestic heat pumps use outside air as the heat exchange medium. That's a different story from a marine system which uses sea water.

The problem with cold water is not efficiency -- reverse cycle heat is still very efficient at 38 degrees. The problem is that when the water is close to freezing temperatures, the condenser can freeze the water and screw everything up. So Dometic systems are limited to 38 degrees water temperature. For times when the water is colder than that, you will need a space heater. But with water temperature from 38 degrees (which is 98% of the time in NYC, I think), the reverse cycle is supreme, producing something like 6x as much heat per kilowatt hour of power consumed than a simple resistance heater like a space heater.

I keep my boat in a fairly cold climate and spend a lot of time on board in the winter. It's kind of quasi living aboard because my boat is my only home in the UK, where I spend a fair proportion of my time. I don't have shore power, however, so I can't use reverse cycle heat. I have an Espar diesel fuel burning central heating system which heats and circulates glycol to make domestic hot water and heat the cabins with fan coils. It works ok, but needs a fair amount of maintenance, and is quite expensive to run -- at full power it burns 1.5 liters of fuel per hour, costing me about $2.50 an hour. Although my boat has a well insulated fully cored hull, it requires just about the full 10kW power of my central heating system to maintain 20 degrees C in temperatures below freezing outside. I would much prefer reverse cycle, if I only had shore power.

[james3]

Originally Posted by Dockhead

Sorry, if you will read your own link carefully, you will see that the outside temperature has nothing to do with the efficiency of the cycle. It is the temperature of the heat exchange medium, not the outside temperature. In this case, it is sea water. So it can be -50 outside or +40, and it makes no difference at all. The amount of BTU's of heat produced depends purely on the temperature of the sea water.

The confusion comes from the fact that regular domestic heat pumps use outside air as the heat exchange medium. That's a different story from a marine system which uses sea water.

The problem with cold water is not efficiency -- reverse cycle heat is still very efficient at 38 degrees. The problem is that when the water is close to freezing temperatures, the condenser can freeze the water and screw everything up. So Dometic systems are limited to 38 degrees water temperature. For times when the water is colder than that, you will need a space heater. But with water temperature from 38 degrees (which is 98% of the time in NYC, I think), the reverse cycle is supreme, producing something like 6x as much heat per kilowatt hour of power consumed than a simple resistance heater like a space heater.

I keep my boat in a fairly cold climate and spend a lot of time on board in the winter. It's kind of quasi living aboard because my boat is my only home in the UK, where I spend a fair proportion of my time. I don't have shore power, however, so I can't use reverse cycle heat. I have an Espar diesel fuel burning central heating system which heats and circulates glycol to make domestic hot water and heat the cabins with fan coils. It works ok, but needs a fair amount of maintenance, and is quite expensive to run -- at full power it burns 1.5 liters of fuel per hour, costing me about $2.50 an hour. Although my boat has a well insulated fully cored hull, it requires just about the full 10kW power of my central heating system to maintain 20 degrees C in temperatures below freezing outside. I would much prefer reverse cycle, if I only had shore power.

What you say it's wrong, there is a basic concept about heat pumps and it's that they move heat from lower source temperature (ex.: 10 °C) to an higher place temperature (ex.: 20°C), the source can be water. air or ground. there are various kind of heating pumps and these can be installed into your house too (of course if you install an water to air heat pump you need a water source as a lake or a river, if you install a ground to air heat pump you need to make a perforation in the ground). The basic concept if that they are able to move heat efficiently just within certain temperatures differences, if the difference between the cold source (where the heat came from) to the warm destination (where the heat goes) it's too big and the cold source is less than 2°C simply the cycle doesn't work. lower is the differences between sources and destination and higher is the performance of the heat pump (it's called CoP Coefficient of Performance) In a marine system you can easily use an air to air heat pump or a water to air system, because it's simpler to reach a water source, but in both cases in winter time the source temp is lower than 40°F (both water and air take a look to this link Ocean Water Temperatures for New York - Current Results ) so the system will be totally non efficient or will not work at all. If you saw a system that works below these temperature it's simply because it has an installed electric resistance that start to works in colder temperature.

[Oliver L.]

Guys,

this thread is funny to watch - too many misperceptions running around...

OK, from a safe physicist's standpoint:

1. There are very few insulating materials better than Balsa wood. Which I can second since my boat has it and I am frequently surprised how hot the deck can be when minutes ago I slept comfortably right below it in a relatively cool cabin. Yes, the infiltration process forms some better-conducting paths, but overall the insulating effect is very good.

2. Heat pumps are based on the Carnot cycle. Essentially (without boring you with formulae) the COP, or coefficient of performance, is inversely related to the temperature rise the heat pump has to perform between the heat source (sea water or outside air) and the heat consumer (fan coils or radiators). If you get a good COP, you get maybe 5...that means, if you need 5 kW of heat, you need 1 kW of electricity - which you cannot really draw from a battery.

3. If you have the option, a direct fire Diesel (or gasoline, for those that have it) heater is the most efficient, quietest and most economic form of heating. Allows you to sleep without running the genset, works underway, if necessary etc. etc.

Considering the weather this summer, I think it is no surprise that we are worrying more about heaters than about air conditioning...

...and now I go back to painting my new bow seats white - two more weeks and they get installed, and shortly thereafter they may get wet...

Oliver

[dirkdig]

On the insulation side there is an air layer in a lot of the 440 hulls.
From the exterior glass then balsa then interior glass layer then air pocket then wood paneling.
Since insulation is based on air pocket between layers of walls the 440 has a lot throughout.
How cold does NY get?

[james3]

Originally Posted by dirkdig

On the insulation side there is an air layer in a lot of the 440 hulls.
From the exterior glass then balsa then interior glass layer then air pocket then wood paneling.
Since insulation is based on air pocket between layers of walls the 440 has a lot throughout.
How cold does NY get?

How is done the 440 hulls ? the 450 has Balsa core hull, solid laminate under water
line, white gel coat, is the 440 the same or it's 100% sandwitch ?

anyway NY waters are really cold into the winter period (from 36 to 42 °F)

[dirkdig]

There is a a layer of fibreglass about 8 mm under the gelcoat then about 22mm of balsa core with another layer of fibreglass of about 5 mm on top on the inside of the hull.
This is all above the waterline and then under that solid fibreglass.
Sitting in cold water makes it harder to heat.
Last summer our 440 was sitting in water that was 36 deg celcius and it was hard to cool the whole boat down.
Standing in the heads the floors were hot.

[james3]

Originally Posted by dirkdig

There is a a layer of fibreglass about 8 mm under the gelcoat then about 22mm of balsa core with another layer of fibreglass of about 5 mm on top on the inside of the hull.
This is all above the waterline and then under that solid fibreglass.
Sitting in cold water makes it harder to heat.
Last summer our 440 was sitting in water that was 36 deg celcius and it was hard to cool the whole boat down.
Standing in the heads the floors were hot.

Ok so the Lagoon 450 and the Lagoon 440 seems to have the same construction process, that's good I was just thinking about buying an used 440 that could be a good deal.

Your boat has been sitting in 36 °C warm sea water ? Where??? It's incredibly warm!!

About insulating, from few year on the building market is available the Aerogel that it's the best insulating material in the world (better than polyurethane, it has been used the aerospace industry),
In this video they make a coat for an apartment with just 1.6 cm thickness panels

https://www.youtube.com/watch?v=r7DL1Xnc5z8

Maybe this could be a good idea to make a boat much more comfortable and save energy for heating and cooling

what do you think about ?

[dirkdig]

We have the 440 in far northern Australia up the top of the great barrier reef and last summer the water was very warm.
If you put that or a similar insulation on he underside of the floor sheets in the hulls that would work to keep the area underwater insulated from the area you need to heat/ cool.
In the roof space in the cabin and hulls you could use fibreglass or polyester insulation batts to pack that space which would work really well just like in a house.
The hardest area to insulate is the windows and hatches.
The standard blinds would do nothing and most other options wold be ugly and impractable.
In the bedrooms you could insulate behind all the wood panels filling the voids with the sheet products or the batts again but once batts are squashed they dont work.
In any method all gaps must be filled.
I think apart from the windows a 450/440 would come up really well.
Might do mine for the heat?

[Hyprdrv]

Well an interesting thread on heating a boat to this point.
Dockhead I believe you were on the right track. James you to had a few good points I just didn't understand your numbers. Dockhead was more on the right track.
The OP stated he had access to plenty of electricity, shore and genset.
He doesn't like gas so rule that out as a heat source. (I tend to agree)
The schedule of water temps. posted shows 3 months where the water temp. is below 40d in NY.
The OP didn't state cost of heating was a major concern.
If my Wife and Daughter want heat to be happy I don't care how much it costs.
So IMO a reverse cycle water cooled heat pump will work great for 9 months of the year with water temps. down to about 40d. Below that the delta'T will fall off and the girls will not be happy. As with most house HP systems an electric backup heater is an option but a more efficient system would be the Hydronic System utilizing the domestic water heater or even better yet a flash heater to circulate water or glycol (even better) to individual coils at major trunk runs controlled by T'stats interlocked to the HP fan. Once the water temperature falls below the ability to provide heat transfer the flash heater would energize, circulate a heated medium to the coils in the ducts and provide warm air.
As far as insulating goes I wouldn't waste the time or energy to insulate the boat any more than it is unless I was in even colder climates then NY. Maine or Alaska probably but then I didn't buy a boat to be up there. One of the biggest issues I've run into is the improper installation of the ductwork and location of registers on my boat. No matter how high (or low in the summer) the air temperature is out of a duct it doesn't do any good if it doesn't get out of the duct. I had kinked ducts, 3 90's in 3 feet of run (a BIG nono) and even a disconnected duct at a register. Don't let an installer just go to town, have a plan and think about where you want the air to go and let him know your ideas.
Anyway that is my opinion, take it for what it's worth.

Steve in Solomons MD
Lagoon 410 SE

[dietmar]

sorry just came across this post Myles - I'm on a lagoon 440 as well - there is an excellent yahoo group called "lagoon catowners" join them as lagoons have a lot of options including air con / heat etc - warm regards dietmar sv carinthia L440 # 258 2008