Using A/C while on a lift
10-01-2006, 09:01 PM
#1
Charter Member
Using A/C while on a lift
Anyone using their A/C with the boat out of the water by inserting a hose in the pick up and letting it hang into the water? Curious if the pump will pull water up 2 feet after it has been primed. Hose will have a checkvalve at the inlet end to prevent it from loosing prime when the unit cycles off.
Thanks
Thanks
10-01-2006, 09:31 PM
#2
21 and 42 footers
Platinum Member
Re: Using A/C while on a lift
all the units I'm familiar with state the pump must be below the water line. I get the impression these things won't pull water very far.
10-01-2006, 09:33 PM
#3
Platinum Member
Platinum Member
Re: Using A/C while on a lift
You'll be running with 2' of reduced water pressure at the heat exchanger. Most AC pumps have moderate running pressure so you might can get away with it assuming you can keep a prime. A check valve is fine, but you'll need to make sure you orient the check valve so that gravity works to your advantage in the way the valve swings shut (unless you use a spring poppet checkvalve).
The GOOD part about your experiment is that you won't hurt anything to try this if you have an AC with a high pressure cutout on the compressor (my Marine AIRs and Cruisairs I've used both DO have the cutout). When you aren't flowing enough cooling water, the compressor's head pressure goes up. Kicks out. Compressor stops cycling. Water pump stops running. Nothing gets hurt.
Even with the check valve, though, you can lose prime on your pump if the valve is not 100% sealed at rest. If this occurs you can cheat.
not only do you run a hose from the pickup to the water, but you run a hose from the discharge to the water. no way for air to get in the system. No way to lose prime.
mc
The GOOD part about your experiment is that you won't hurt anything to try this if you have an AC with a high pressure cutout on the compressor (my Marine AIRs and Cruisairs I've used both DO have the cutout). When you aren't flowing enough cooling water, the compressor's head pressure goes up. Kicks out. Compressor stops cycling. Water pump stops running. Nothing gets hurt.
Even with the check valve, though, you can lose prime on your pump if the valve is not 100% sealed at rest. If this occurs you can cheat.
not only do you run a hose from the pickup to the water, but you run a hose from the discharge to the water. no way for air to get in the system. No way to lose prime.
mc
10-02-2006, 08:54 PM
#5
Re: Using A/C while on a lift
Originally Posted by mcollinstn
....... you can cheat.
not only do you run a hose from the pickup to the water, but you run a hose from the discharge to the water. no way for air to get in the system. No way to lose prime.
mc
not only do you run a hose from the pickup to the water, but you run a hose from the discharge to the water. no way for air to get in the system. No way to lose prime.
mc
Such a simple solution.
Thanks guys
10-02-2006, 09:06 PM
#6
Re: Using A/C while on a lift
The suitcase type AC units have a submersible pump in a little cloth bag. You throw it over the side and it then pumps very well. The bag keeps the thing from clogging and can be rinsed out when you're done. You could do this with any submersible AC pump and use it all the time like that even when the boat is down.
