Heating and Air Conditioning Pumps-Water or Oil Cooled

[Craig Curtis]

Fluid Dynamics (a class I never took)

I need to replace the burnt out seawater circulation pump on my Cruissair Heat/AC system. My old unit was a water cooled pump which is susceptible to overheating and burning out if it runs dry for over a minute. Oil cooled pumps, of which Cal seems to be the main manufacturer, tout an ability to run dry and not burnout. On top of that they cost about a third less for the BTU capacity that I need. Are there any disadvantages to an oil cooled pump that would account for this disparity in price for a product that seems to have an inherent advantage from the one point that I'm comparing them on?

Thanks in Advance,

Craig Curtis
CD40 "Coalescence"
Chicago



Craig_Curtis@prusec.com

[Bob Loewenstein]

Craig,

The Cal pump you mention has some contradictory info:

West Marine says "can run dry without failing"

BoatUS says "Cannot be run dry"

The pump does have a heat sensitive shutoff, but the question is will it shut off early enough. I'd call the manufacturer to clarify what you'd be getting before you order.

I had a Seal-less pump (used to be a different name) quit on me but found the pump on sale for $149 2 years ago (580g/m).

Bob

[Ken Coit]

Craig,

There's some info on Cal Marine Pumps at the link below. Looks like they can run dry for some amount of time, but not "unlimited." I suppose this has to do with the pump lube, not the motor, as the motor seems to be sealed and permanently lubed. Perhaps there is an issue with motor cooling over a period of time.

Good luck!

Keep on sailing,

Ken Coit
CD/36 Parfait
Hailing Port: Raleigh, NC
Sailing from: Beaufort, NC

Fluid Dynamics (a class I never took)

I need to replace the burnt out seawater circulation pump on my Cruissair Heat/AC system. My old unit was a water cooled pump which is susceptible to overheating and burning out if it runs dry for over a minute. Oil cooled pumps, of which Cal seems to be the main manufacturer, tout an ability to run dry and not burnout. On top of that they cost about a third less for the BTU capacity that I need. Are there any disadvantages to an oil cooled pump that would account for this disparity in price for a product that seems to have an inherent advantage from the one point that I'm comparing them on?

Thanks in Advance,

Craig Curtis
CD40 "Coalescence"
Chicago

[img]http://www.calpump.com/images/cal_marin ... 04_c03.jpg[/img]
parfaitNOSPAM@nc.rr.com

[Ken Coit]

Is it possible that this might be a problem?

Ken

Fluid Dynamics (a class I never took)

I need to replace the burnt out seawater circulation pump on my Cruissair Heat/AC system. My old unit was a water cooled pump which is susceptible to overheating and burning out if it runs dry for over a minute. Oil cooled pumps, of which Cal seems to be the main manufacturer, tout an ability to run dry and not burnout. On top of that they cost about a third less for the BTU capacity that I need. Are there any disadvantages to an oil cooled pump that would account for this disparity in price for a product that seems to have an inherent advantage from the one point that I'm comparing them on?

Thanks in Advance,

Craig Curtis
CD40 "Coalescence"
Chicago

parfait@nc.rr.com

[Craig Curtis]

Ken,

No, as the one it will be replacing was installed below the waterline as well. Specifically, it's installed beneath the galley sink on the cabin sole. They are considered "non-self priming" and therefore they have to be beneath the waterline.

Is it possible that this might be a problem?

Ken

Fluid Dynamics (a class I never took)

I need to replace the burnt out seawater circulation pump on my Cruissair Heat/AC system. My old unit was a water cooled pump which is susceptible to overheating and burning out if it runs dry for over a minute. Oil cooled pumps, of which Cal seems to be the main manufacturer, tout an ability to run dry and not burnout. On top of that they cost about a third less for the BTU capacity that I need. Are there any disadvantages to an oil cooled pump that would account for this disparity in price for a product that seems to have an inherent advantage from the one point that I'm comparing them on?

Thanks in Advance,

Craig Curtis
CD40 "Coalescence"
Chicago

Craig_Curtis@prusec.com

[John R.]

I like the "Teel" brand pumps. They are very quiet, oil like the Cals. They do get quite warm. Short term run dry and must be installed below the waterline. Every A/C recirc pump I've ever installed required they be installed below the waterline.

Fluid Dynamics (a class I never took)

I need to replace the burnt out seawater circulation pump on my Cruissair Heat/AC system. My old unit was a water cooled pump which is susceptible to overheating and burning out if it runs dry for over a minute. Oil cooled pumps, of which Cal seems to be the main manufacturer, tout an ability to run dry and not burnout. On top of that they cost about a third less for the BTU capacity that I need. Are there any disadvantages to an oil cooled pump that would account for this disparity in price for a product that seems to have an inherent advantage from the one point that I'm comparing them on?

Thanks in Advance,

Craig Curtis
CD40 "Coalescence"
Chicago

[Ken Coit]

Craig,

I should have mentioned some time ago that Parfait had a problem with her Crusair pump and I was able to get it running full steam again simply by disassembling the pump and cleaning it out. Over the years, it had accumulated some deposits in the pump housing itself and the pump impeller would not turn. Since the coupling is magnetic, and perhaps because I didn't run it long once I discovered it wasn't pumping, the motor was fine.


Keep on sailing,

Ken Coit
CD/36 Parfait
Hailing Port: Raleigh, NC
Sailing from: Beaufort, NC

Fluid Dynamics (a class I never took)

I need to replace the burnt out seawater circulation pump on my Cruissair Heat/AC system. My old unit was a water cooled pump which is susceptible to overheating and burning out if it runs dry for over a minute. Oil cooled pumps, of which Cal seems to be the main manufacturer, tout an ability to run dry and not burnout. On top of that they cost about a third less for the BTU capacity that I need. Are there any disadvantages to an oil cooled pump that would account for this disparity in price for a product that seems to have an inherent advantage from the one point that I'm comparing them on?

Thanks in Advance,

Craig Curtis
CD40 "Coalescence"
Chicago

parfaitNOSPAM@nc.rr.com

[Craig Curtis]

Ken,

Thanks for the suggestion on a potential alternative. FYI, in case you ever do need to replace the Cruisair pump in the future you'll find that they no longer make pumps. However, I've found out that Cruisair never really in fact made their own pumps, they were just private labeled March pumps.

Thanks again to you, Bob and John for your responses.

Best Regards,

Craig Curtis
Cape Dory 40 "Coalescence"
Chicago, where hopefully I won't need the heat or air for a while.



Craig_Curtis@prusec.com