Heating / Air Conditioning - What's the Consensus ?

[eisselhardt]

So, my survey and sea-trial were scheduled for tomorrow. The guy my broker recommended to install heating and air in the Beneteau 381 called this afternoon to say that since I'll be living aboard (with my 6 year-old daughter), he recommended a diesel heating system and two air units. Total cost about $18K. He said I could get away with one air unit, but the price would still be in the $13K range.

Called my broker to say, "Whoa!" on the survey. I don't want to spend $18K for this on a $85K boat. He says, well then don't. Have the guy put in one air unit for the main salon, and run two space heaters for when the reverse cycle won't cut it in the winter. He says this is far superior to diesel. Cost for that solution is around $7K.

I said, well, I'm going to check in with folks on a couple of forums to see what their experiences have been.

We'll be living full-time in the D.C. area. It gets cold here. It gets hot here. What do you all think?

[djmarchand]

I lived aboard one summer on a 43' sailboat in Annapolis. With an awning covering 2/3 of the boat, one 16,000 btu A/C just barely kept it reasonably cool- maybe 78 deg in the middle of a 95 deg full sun day.

Reverse cycle heat stops working at below 45 deg sea water temp, which is from Dec to March. So no help there. Two 1500 watt space heaters won't quite do it either.

What you could do is use a portable kerosine heater during waking hours and bundle up at night with only the two 1500 watt space heaters going. A 20,000 btu/hr kerosine unit costs about $100 and is equal to 6000 watts. One should heat your whole boat pretty well. IMO they are safe as long as you are awake. Yes I know that CO will put you to sleep, so install a CO detector. That is about the best you can do without diesel heat.

Diesel heat is by far the best solution but it is expensive. There are three types: bulkead mounted vented like the Dickinson- $2,500 , forced air like the 18 wheeler cabs use- $4000 and hydronic (hot water circulation)-$10,000 . Hydronic is the best and will keep your boat uniformly warm, but you pay for it.

If money is a big problem and you are only going to live aboard for a year or so, then install one 16,000 btu A/C for the summer and use the space heaters with a kerosine heater for the winter.

Oh and do you have a live aboard slip lined up. Not easy to come by.

David

[Prerequisite]

I avoided installing AC on my boat all summer (I liveaboard in FL at a dock). It was HOT, but eventually humidity won over- I was seeing some issues arise in the cabin so I caved. My life has been so much better ever since so I suspect you'll be happy having climate control on board.

The problem you might run into with reverse cycle is that most units need the water temp to be above 50 degrees to function correctly. The Potomac gets pretty darn cold so expect to need an additional heat source. Definitely get reverse cycle units though because they hardly cost any more than cooling only units and they are the same size.

You can do the installation yourself and careful planning along with judicious purchasing will save you some money. You do need to carefully consider the size unit you go with- there is some good info on the net if you search. I have a 12k unit in my Cape Dory 33 (again in FL) that doesn't short cycle, but would ideally run a little longer than it does.

If I ever take my boat extended cruising I'll pull the unit back out, but as long as it spends most of it's time at the dock I love it!

[boatman61]

I think this is the best answer to your winter heat problems...
Taylors heaters and cookers

[witzgall]

You can install the diesel forced air furnaces yourself - I just did so myself. If you break it down several projects, it is not too bad.

If I were to install a heating system for a live aboard boat, I would try and install hydronic. If living at the doc, many use electric, kero, and their reverse cycle.

Maybe you can do much of the grunt work of installing the system, and have the pro do the final hookups, etc?

Chris

[colemj]

You should also have the option of electric heating elements in the AC system instead of, or in addition to, reverse cycle. This will keep the cost down (no separate heating system) and be much more efficient than space heaters because it will use the duct work and be higher wattage.

Mark

[J Clark H356]

In Washington DC you are going to have hot humid summer weather as well as cold winter weather. My Hunter 356 has a 16,000 BTUH Marine Aire system.The system is a water source heat pump. It works well for heating when the water temperature is in the low 40's. and will cool well into the high 80, low 90 degree temps. I think Washington will be somewhat close to the conditions we face at Kentucky Lake. If I were you, I'd look for another boat that has a system like mine already installed or install a system like mine. You can use additional ceramic heaters for ultra cold weather. You should be fine in the summer.

[Bergovoy]

Originally Posted by djmarchand

I lived aboard one summer on a 43' sailboat in Annapolis. With an awning covering 2/3 of the boat, one 16,000 btu A/C just barely kept it reasonably cool- maybe 78 deg in the middle of a 95 deg full sun day.
David

Land based ac units typically are good for 10-15 degree cooler then ambient temperature (per stage). that means you can get a two stage to get more cooling from the ambient/supply air...

so, your ac is working well.. the issue is the area you are trying to cool. the smaller the area the quicker it will achieve that temp and keep....

one thing i dont understand about marine AC units is that they need water... all the documents i have seen show a through hull and electric pump to recirc that water back out to sea....

and the pumps are good sized, meaning htey flow a bunch of water... Landbased AC units dont use water... some evaporative cooling systems may use some water, but that is a trickle/drip...

so, if anyone can enlighten me on how or why marine AC need lots of water, i would appreciate it thanks


b

[J Clark H356]

The marine units you are referring to that use seawater are water source heat pumps. They use the extracted heat in the water to either heat or cool making the transfer from water to air. A heat pump on land is an air to air transfer. There are also buildings that are heated and cooled using water to air heat pumps similar to boats. These are well driven or geothermal.

[Bergovoy]

hello and thanks for the info... i was unsure on how heat pumps worked... i am guessig they are more efficient? as i see a lot of marine AC units that are this style?

[sparklegirl50]

We live aboard in Baltimore, and it truly does get hot and humid in summer, and can be downright cold in winter. Add in winds, and it gets colder still. Not much sun, colder yet.

We have both a heat pump, and a diesel heater. The issue with the heat pump is that below 40 deg. water temp, it does not work. You also have the problem of condensation.

The diesel heater works well. Nice and warm, dry heat, no condensation.

I think your daughter will be happier (speaking as a girl), if she does not have to worry about her stuff being ruined by indoor rain, or having to wear heavy clothes inside all the time because it is too cold.

Put rugs down too; the floors will be cold in the winter.

[KDH]

Make sure you get more than one quote on the work. If this boat already has the vents and cutouts for duct work (ie you want to replace non functioning unit rather than non-existent) I agree you could do it yourself provided you had professional advice or knowledge on wiring the unit. I spent 99% of my time last summer, in Deale, Md 20 miles or so from downtown DC. With 104 F outside and an awning on the main cabin, 31 foot Hunter with lots of opening ports and fans, I managed to get the temp down to about 97. NOT a good environment for a small child as they have a more difficult time regulating their core temp than an adult. If you are at the dock then you will absolutely need some form of temp regulation. We bought, after the 3rd 104 day, a drop in airconditioner, for 200$ or so. Put it in the forward hatch and it dropped the temp to a tolerable level. Unfortunately, you can only run 1 unit through the electrical and nothing else other than the dc circuit (ie. wall mounted fans). So, I suggest you put in the AC and diesel heat if you do not anticipate longterm cruising. However, I often see in other cruisers pictures those enclosed loop, radiator type heaters and if you don't go the diesel route, one of those would be a much safer solution with a 6 year old onboard. If you are not committed to living in DC, you might want to check out Deale. Nice small town, nice looking school. Best of luck to you and your daughter!

[btrayfors]

Give me a buzz; be happy to talk to you about live-aboard heating options in D.C. I lived aboard for 17 years, and have had boats here over the winter for more than 20 years. I'm familiar with all the options, and most of the vendors.

There are some nuances you don't want to miss before you decide.

email: bill at wdsg dot com

Bill

[ardoin]

I have a Cruise Air system (16,000BTU) and it works great in the summer, one compressor and two evaporators. I don't use it in the winter. I had a Webasto, but replaced it two years ago with a Hurricane. The Webasto was unreliable and maintenance was an expensive PITA. The Hurricane is easy to maintain. Did the installation myself to save some $s. Still not cheap, but the boat is oh so warm in the winter.
Also hatch covers help in the summer and bubble wrap in the hatches is great in the winter.
There are lots of boats on the market, look for one that has most of the systems already installed and in good condition.

[eisselhardt]

Thanks everyone for your comments. After hearing all of you, as well as the posts from other forums I frequent, I've decided to go with a reverse cycle air/heat system plus a deisel furnace system. Although I don't have time or inclination to install those myself, I will look for a boat with one or the other, and have the other installed. Of course, I'll keep my eye open for something with both already.

Again, thanks to all who replied!
Eric