Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-04-2017, 09:05 PM   #1
Veteran Member
 
City: San Diego
Country: America
Vessel Name: Fishbone
Vessel Model: 1990 Nova/ sedan
Join Date: Jan 2014
Posts: 38
A/C heat exchanger operation

folks,
I did a search but couldn't find it.

my last live aboard had electric box heaters in each space. I am moving on to a new boat that has 2 A/C heat exchangers, and I got to thinking about its use. I live in san diego, with the mild winter I wouldn't expect the heater to come on but a few times during the evening.
so the question is, do you leave the pump on all night to support the heater? that doesn't sound very efficient. are these units suitable for live aboard use, or should I use an electric blanket/ space heater?

thanks
__________________
Advertisement

Lunasea is offline   Reply With Quote
Old 02-05-2017, 12:08 AM   #2
Guru
 
drb1025's Avatar
 
City: Bellevue, WA
Country: USA
Vessel Name: Fiddler
Vessel Model: DeFever 46
Join Date: Oct 2012
Posts: 588
On my reverse cycle units, the thermostat has a setting to have the cooling pump on only when the condensers run. It is a Marine Air/Dometic unit with the Passport thermostat control.
__________________

drb1025 is offline   Reply With Quote
Old 02-05-2017, 06:38 AM   #3
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23
Join Date: Aug 2012
Posts: 4,554
I presume you are talking about a reverse cycle A/C cooing/heating system. Two heat exchangers? Does that mean one compressor and two fan/coil units (a split system) or two compressor units?

If one compressor then the raw water pump will come on when the compressor comes on. With two compressors and one raw water pump serving both, then there is often a relay installed which lets the raw water pump run when one or the other compressor is running.

You should not have to run the raw water pump all night. If so then you need to get a marine electrician to set up the relays.

David
djmarchand is online now   Reply With Quote
Old 02-05-2017, 06:45 AM   #4
Guru
 
ranger42c's Avatar
 
City: Maryland
Country: USA
Vessel Model: 42' Sportfish
Join Date: Aug 2013
Posts: 4,338
Quote:
Originally Posted by drb1025 View Post
On my reverse cycle units, the thermostat has a setting to have the cooling pump on only when the condensers run. It is a Marine Air/Dometic unit with the Passport thermostat control.

Yep, ours is probably similar.... although we have no setting that causes the pump to run all the time.

Two Marine Air ACs, each with its own thermostat (Passport II controls), and one water pump to support both ACs.

Our water pump only runs when the thermostat causes one or the other AC compressors to run.

We DO have a setting to control whether the blower (fan) on each unit runs continuously or only when it's condenser is on. In fact, we vary that, depending on time of year. In mild weather, we cycle the fans when the condensers come on. In July and August, we usually run the fans continuously.

-Chris
__________________
South River, Chesapeake Bay
ranger42c is offline   Reply With Quote
Old 02-05-2017, 07:05 AM   #5
Senior Member
 
bluebyu's Avatar
 
Vessel Model: Gulfstar 38MC
Join Date: Oct 2007
Posts: 341
..... And electric mattress cover, not blanket.
bluebyu is offline   Reply With Quote
Old 02-05-2017, 07:10 AM   #6
Guru
 
psneeld's Avatar
 
City: ACIW
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 19,105
Quote:
Originally Posted by bluebyu View Post
..... And electric mattress cover, not blanket.
.....love mine, never liked the electric blankets.
psneeld is online now   Reply With Quote
Old 02-05-2017, 08:55 AM   #7
Veteran Member
 
City: San Diego
Country: America
Vessel Name: Fishbone
Vessel Model: 1990 Nova/ sedan
Join Date: Jan 2014
Posts: 38
yes, they are 2 separate units. when we did the sea trial and tested them they were on the whole time. it didn't occur to me that they might have a relay and cycle on and off. something else to look forward to when we take ownership next week.


thanks for the replies
Lunasea is offline   Reply With Quote
Old 02-05-2017, 09:27 AM   #8
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 5,136
San Diego is a perfect place for reverse cycle heat and AC. When you do want heat, they will work fine due to moderate temps. Resistance style heat is necessary when super cold, where rev cyc performance is poor.
Ski in NC is online now   Reply With Quote
Old 02-05-2017, 01:15 PM   #9
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 19,121
When its cold and the electric on the dock leaves , these are the best way to be able to ignore the temp.



In the AM you can winterize the engine and other systems , while hoping the juice will come on , eventually.




Amazon.com: Twin, Heated Mattress Pad by Electrowarmth, Non ...

https://www.amazon.com/Mattress-Elec....../B001122SZQ


Rating: 4.4 - ‎47 reviews
RoadPro RP-203EC 12V 12' Extension Cord with Cigarette Lighter Plug. + ... Electrowarmth bunk warmers radiate heat from below allowing you to relax into a ..
FF is offline   Reply With Quote
Old 02-05-2017, 01:39 PM   #10
Guru
 
Alaskan Sea-Duction's Avatar
 
City: Inside Passage Summer/Columbia River Winter
Country: USA
Vessel Name: Alaskan Sea-Duction
Vessel Model: 1988 M/Y Camargue YachtFisher
Join Date: Jul 2012
Posts: 4,567
The water pump (at least on mine) runs when ever the unit is turned on, to include in fan position. When the switch is in run position the compressor cycles on and off. I have two units and one pump.
__________________

__________________
Alaskan Sea-Duction
MMSI: 338131469
https://alaskanseaduction.blogspot.com/
Alaskan Sea-Duction is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 07:24 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012