siting 9.2A HVAC

Apr 27, 2011
423
S2 9.2A Newport News, VA
I guess I'm the sailing equivalent of the guy with the $200 car and $2000 rims. I have a great time adding and updating features WAY beyond what's reasonable, particularly if you're looking at being able to recapture your investment when it's time to sell. With that in mind, I've been looking at getting a Webasto FCF9000 (9000 BTU, not surprisingly) unit. It seems a very straightforward unit to install, if there is such a thing when it comes to HVAC.

My question is, where to put it? Currently the best spot, it seems to me, is in the hanging closet opposite the head. The unit is something like 15" wide by 12.25" deep by 16" high. They want about two inches breathing space on either side, and two inches on the back. I think I can accommodate that fairly easily if I remove at least the lower divider between the two cabinet halves.

The nice thing about this location is I can run the output up to a box (maybe a six inch cube?) that would butt up against the forward bulkhead. I'd cut an opening in the box and the bulkhead for a 4" grill to cool/heat the v-berth, and put another 4" grill to output air toward the cabin and galley. I could have a third opening facing the head, which you might open if you were showering.

Anyone see any obvious problems with this arrangement?

Incidentally, I've got the water heater in and it's hot, hot, hot! I've ordered an automatic mixing valve to tone it down to a safe level (more fun than just adjusting the thermostat), and will post results and pics to that thread once it's in.

Could a windlass be next?

I may come back and list some more details on the Webasto later, but I should get back to work!

Thanks.

John
 

Attachments

Sep 15, 2009
6,243
S2 9.2a Fairhope Al
That looks like good unit John. The space is about all you have for placement. You may want to look at the 12,000 I have a 16,000 only because of the deal I got on the unit
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
Good to hear you agree with the placement. I think the dimensions for the 12,000 are very similar, so I'll check that.

What brand is yours, Woody?

John
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Good to hear you agree with the placement. I think the dimensions for the 12,000 are very similar, so I'll check that.

What brand is yours, Woody?

John
ocean breeze...its got an electric heating element 2 k
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
I really don't have a thorough understanding of how these units work. The Webasto has "reverse cycle heat," which I assume is the same thing as your home's heat pump, exept you're moving heat in one direction or another through the water under the boat, instead of the surrounding air. Having a heating element like yours either adds more heat at any given water temp or (and?) keeps the unit producing heat when there's not really any to remove efficiently from the water. Is that how it works? Do you know at what water temp the element becomes mandatory? The manual says it can heat "effectively" with water as low as 40 degrees. Doesn't seem like I'm going to encounter anything lower than that, but I could be wrong.

With your larger unit and heating element, are you still expecting to run on 30AMP service?

I'm looking for the BTU heat output of the Webasto, but haven't found it. I'd like to compare it to the space heater I currently use to keep the cabin bearable, if not fully comfortable, in winter.

John
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
I really don't have a thorough understanding of how these units work. The Webasto has "reverse cycle heat," which I assume is the same thing as your home's heat pump, exept you're moving heat in one direction or another through the water under the boat, instead of the surrounding air. Having a heating element like yours either adds more heat at any given water temp or (and?) keeps the unit producing heat when there's not really any to remove efficiently from the water. Is that how it works? Do you know at what water temp the element becomes mandatory? The manual says it can heat "effectively" with water as low as 40 degrees. Doesn't seem like I'm going to encounter anything lower than that, but I could be wrong.

With your larger unit and heating element, are you still expecting to run on 30AMP service?

I'm looking for the BTU heat output of the Webasto, but haven't found it. I'd like to compare it to the space heater I currently use to keep the cabin bearable, if not fully comfortable, in winter.

John
John ...mine is a heating element only for heat ..i don't have the reverse cycle
it has a power requirement of 30 amp but in reality only draws 17 amps when running ...there is a brand flag ship marine that looks to be the same unit they as i under stand it were at one time one and the same but i haven't confirmed that as fact the only reason i have this brand is it was one of those deals i couldn't pass up...having said that it is still a good unit ...i still need to do some thing about heat when i am away from the dock ...i am looking at the diesel units for that ...and it will come later after i splash but it will come ...as for the BTU on the webasto i am assuming that if it says 9000 then its a 9000 and so on ...i did notice in your pic of the one you are looking at that it had a grilled water inlet for a through hull fitting ...replace that with a mushroom type or you will be mad down the road ...

happy t day
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
I was at the boat today still trying to get one last plug out of the fresh water pump to finish the water heater install. I got nowhere with that, so I killed some time (a pretty day to be around the water, but a bit too windy to be out on it) taking measurements of the interior, hoping to nail down the cooling BTU requirements. Please take a look at these measurements and see if you think they're reasonable. Precise, they're not.

S2 9.2A interior volume

V-Berth area: height 4 x width 6 x length 6 = 144 CF
Passage: 6 x 3 x 4 = 72 CF
Head: 6 x 3 x 3 = 54 CF
Salon/Galley: 6 x 9 x 8 = 432 CF
Q-Berth: 3 x 3 x 5 = 45 CF

Total: 747 CF

You're supposed to multiply by 10 (given my relatively temperate area of southern Virginia) to get your approximate BTU requirements. Seems, then, that a 9000 BTU unit ought to do it. I've got one of those portable Cruise Air jobs that I think is rated at 5000 BTU and it can almost cut it.

I think the 9K Webasto will fit comfortably, while the 12K unit would push it a bit space-wise and on my 30 AMP service, given what else is typically running.

John
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
9000 will probably do it but i still think one size up would be better for those extra hot days and it will not run as hard one size bigger ...i may have to get a dog to wake me up right before i freeze to death with the size i have 16000 but then it was a deal i couldn't pass up
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
9000 will probably do it but i still think one size up would be better for those extra hot days and it will not run as hard one size bigger ...i may have to get a dog to wake me up right before i freeze to death with the size i have 16000 but then it was a deal i couldn't pass up
You're recommendation for the 12K unit is certainly part of the decision process. There's very little difference in price, so that's not an issue.

9000 = 15¾" x 15¾" x 12½" (depth, width, height)

12000 = 16" x 17¾" x 14"

It's the two extra inches of width that concern me. With the smaller unit, I could probably still use the starboard settee as a berth (Webasto wants two inches on either side of the unit for air circulation), but I'm not so sure with the 12000.

I'll post the electrical requirements a bit later. It's time for a nap!

John
 
Last edited:
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
You're recommendation for the 12K unit is certainly part of the decision process. There's very little difference in price, so that's not an issue.

9000 = 15¾" x 15¾" x 12½"

12000 = 16" x 17¾" x 14"

It's the two extra inches of width that concern me. With the smaller unit, I could probably still use the starboard settee as a berth (Webasto wants two inches on either side of the unit for air circulation), but I'm not so sure with the 12000.

I'll post the electrical requirements a bit later. It's time for a nap!

John
don't you have louvered doors on that cabinet ...i don't think that space will be a problem...make a cardboard patter of the foot print and set it in there and see how much room you have...you can always glass in a shelf higher up to get the foot print you need and still make the starboard settee a sleeping berth
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
I will make up a couple of cardboard patterns to check the footprint of each model today.

Here are the electrical requirements:
9000 BTU unit: 10A breaker, average current draw, 7.2A
12000 BTU unit: 16A breaker, average current draw, 10A

Other current drains:
fridge: .7A
water heater: 10A
battery charger: 6.5A at full load, but probably normally only 1A or so.
I'll run the water and bilge pumps to see how much they increase the charger's load.

I did briefly try fitting a box about the size of the 9000 BTU unit, and even that will take some work, mostly due to the rather large water fill hose that's toward the back of the compartment.

John
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
I will make up a couple of cardboard patterns to check the footprint of each model today.

Here are the electrical requirements:
9000 BTU unit: 10A breaker, average current draw, 7.2A
12000 BTU unit: 16A breaker, average current draw, 10A

Other current drains:
fridge: .7A
water heater: 10A
battery charger: 6.5A at full load, but probably normally only 1A or so.
I'll run the water and bilge pumps to see how much they increase the charger's load.

I did briefly try fitting a box about the size of the 9000 BTU unit, and even that will take some work, mostly due to the rather large water fill hose that's toward the back of the compartment.

John
are you trying to put that in the single door cabinet or the double door cabinet...i would opt for the double door cabinet but it will be ok in the single the only thing about the smaller one is it may work you to death installing it as there is not much room in the hall way for you and the unit at the same time ...by using the double you can run a duct out the top and the side blowing back to the galley and also duct the v berth with a short piece of duct and a grill

oh BTW i posted pics of the cabin sole install a few days ago in that thread
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
Now that the chainplate knee has been repaired, I removed the shelf in that cabinet and placed the new Webasto HVAC unit in there. The shelf will go back in once I've made cut outs for the ducting.

The arrangement looks pretty good. As Woody suggested, I plan on routing the ducting forward to the V-berth, with the other, primary outlet on the aft side of the cabinet, facing the starboard settee and galley. I'll add some pics of the basic set up. I haven't finalized the location of the thermostat yet. I need to see how long the cable is and how easily I might extend it. Optimally, I should think it would be located over near the electrical panels.

Once the basic set up is up and running (and there's lots to do before that happens), I'm thinking about running a closable vent aft to the engine compartment, so I can keep that and the water heater warmish during the winter.

I've got a Mermaid Condensator on order, with combines the condensation with the sea water discharge, so condensation does end up in the bilge. There's an unused seacock under the starboard settee for the seawater inlet. I'll need to put in a new thru hull for the discharge. And then there's my overcrowded and disorganized electrical panel to deal with. The fun never ends!

John
 

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BobM

.
Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
I'd mount the thermostat on the bulkhead on the cabin side. It will be between your two vents in a relatively dead zone of air circulation and should give you a worst case reading of the true temperature of the space. Plus it is easy to run a wire to from the unit.
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
Thanks, Bob. That's a great idea. Simplest is best. I did check the cable and it's long enough to run over by the quarter berth, but I'm going to try your suggestion first.

John
 

BobM

.
Jun 10, 2004
3,269
S2 9.2A Winthrop, MA
I would try to affix it temporarily to see what works. Keep it out of the sun too.
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
Progress on many fronts in recent weeks. I'm particularly pleased with how the port settee extension is working out (details to follow) and, even better, the HVAC is working great! There are still a few finishing bits to do, but I let it run about ten minutes yesterday. It was 85 in the cabin when I fired the unit up. Attached you see a shot of my IR thermometer reading the air flow at the main vent. Yowsers! To handle the condensate, I will probably have to go from 3/4" seawater output hose down to 1/2" at the thru-hull, which may make it a bit less efficient, but we'll see. Once the condensation issue is resolved, I'll post a bunch of pics of the install. It was pretty straightforward once I got Webasto to admit their instructions were wrong!

Incidentally, that Webasto FCF 9000 moves a TON of air, even at the lowest fan setting.

John
 

Attachments

Sep 15, 2009
6,243
S2 9.2a Fairhope Al
Progress on many fronts in recent weeks. I'm particularly pleased with how the port settee extension is working out (details to follow) and, even better, the HVAC is working great! There are still a few finishing bits to do, but I let it run about ten minutes yesterday. It was 85 in the cabin when I fired the unit up. Attached you see a shot of my IR thermometer reading the air flow at the main vent. Yowsers! To handle the condensate, I will probably have to go from 3/4" seawater output hose down to 1/2" at the thru-hull, which may make it a bit less efficient, but we'll see. Once the condensation issue is resolved, I'll post a bunch of pics of the install. It was pretty straightforward once I got Webasto to admit their instructions were wrong!

Incidentally, that Webasto FCF 9000 moves a TON of air, even at the lowest fan setting.

John
thats great news john glad you are having success with the projects......

as a friend of mine told me you better get you a big loud dog with that much cooling so he can wake you up right before you freeze to death .......
 
Apr 27, 2011
423
S2 9.2A Newport News, VA
I'm assuming that vent temp will come up a bit as the water temperature rises. Nice starting point, though! And I do have two pit bulls that don't mind letting me know when they're uncomfortable.
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
I'm assuming that vent temp will come up a bit as the water temperature rises. Nice starting point, though! And I do have two pit bulls that don't mind letting me know when they're uncomfortable.
bring it down here and you will see how high it will get in july and august when the water temp is 85 deg