AC size

[mitchellp]

I need to replace my salon ac unit on a 1989 Carver 38 aft. There is no information on the unit itself.
What size of unit do I need? 12,000 or 16,000 btu

thank you
Mitch

[buster53]

Are you on the Great Lakes or Florida coast? I assume you have 3 units on that boat and if so, I think the salon unit is 12k.

[g36]

My 405 aft cabin has 16000 in salon

[buster53]

QR_BBPOST My 405 aft cabin has 16000 in salon

OP didn’t say, but sounds like he has a 3807. I used to have a 3807 and if I recall, the salon was 12k.

[g36]

I think their cu ft interior spaces of the 2 boats is pretty similar (just googling)but I do know with all the windows there's a lot of thermal transfer on both which ever he has ... I know I would not want any smaller, maybe even larger down here in Tennessee .

[Midnightsun]

For what it's worth, mine came with a 16,000 btu for the salon and there is an 11,000 in the forward cabin that also partially supplies the salon. Point is the salon needs quite a bit to keep up. That being said I would definitely go with a 16,000 btu.

[buster53]

You have to be careful with sizing and electric draw. When we had all 3 AC units running on our 3807, we were pulling 29 amps. If we had replaced just one of those units with one another size larger, we would have exceeded the 30 amp limit, meaning we would only be able to run 2 units, not all 3.

[g36]

I would have thought a 3807 would have had 50 amp 120 service x2 like my 405 does instead of only 30 amp. Newer units would probably more energy efficient which will help too.

[Midnightsun]

QR_BBPOST I would have thought a 3807 would have had 50 amp 120 service x2 like my 405 does instead of only 30 amp. Newer units would probably more energy efficient which will help too.

Or at the least dual 30's. Usually as soon as AC is added as an option they kick in an additional 30a inlet and in the case of multiple AC units dual 50a 110 or single 50a 220 is the norm.

[buster53]

I would have thought a 3807 would have had 50 amp 120 service x2 like my 405 does instead of only 30 amp. Newer units would probably more energy efficient which will help too.

Yes, my 3807 did come from the factory with dual 50 amp, 120 volt service, however, when was the last time you saw a marina that offered 120-50 amp? I never have. Previous owner had special shore power cords made up…male 120-30 amp with female 120-50 amp. That way, the boat could be plugged in at any marina as all offer 120-30.
One cord powered all 3 AC units, other cord powered everything else.