Hartford loop / check valve considerations

[tonygiotta]

I understand the concept of a Hartford loop, and I understand that for maximum effectiveness it should be inside the spa wall. What I'm having a tough time with is that my PB is advising that he doesn't like putting them in the spa wall as he says they require a check valve on the wet side of the loop which would make the check valve unserviceable should it develop an issue. None of the plumbing photos I've come across on TFP show a check valve inside the rebar frame, yet every Hartford loop diagram I see on Google shows there should be one there. What gives?

 

[mas985]

Sometimes a check valve is used sometimes not. If the loop is sufficiently high above the spa water level, then you may not need a check valve. The idea is that it prevents the water from going over the loop. I would probably not put in a check valve in the spa wall either because they do fail and not so infrequently. But there may be other options.

Also, sometimes you can get away without a Hartford loop if and only if the air pipe that runs back to the pad equipment or wherever it terminates is uphill.

Also, if you can put a loop within about 10' of the spa, that would also work but then again, you could just put an air inlet right there too. Simply putting an air inlet as close to the spa is really the best option plus you won't need a blower either.

 

[JoyfulNoise]

My above ground spa was only built with a Hartford loop, no check valve on the air line. The pipe runs maybe 20ft back to the equipment pad with no blower attached. My spa never has trouble getting enough air and the jets are plenty powerful enough with my IntelliFlo set only to 2500RPM for SPA Mode. I suppose if I went all the way up to full speed (3450RPM), I could probably blow off everyone's bathing suits....hmmmmm, now there's an idea

 

[tonygiotta]

Thanks for the replies. My spa is going to be 18" above pool/deck level. My yard is relatively flat, guessing I'll only pick up about 3" of elevation gain over the 25ft run from my spa to the equipment pad. Guess that puts my airline at 15" below my spa water level?

I just included the link to my build thread in my signature. First post has a picture of my plan. The spa is surrounded by an 18" raised deck. I could easily have the air intake pop out the back of my deck without even having to dip below water level. I have two concerns however... #1 would having the air intake that close cause excessive sucking/gurgling noises with the jets running? #2 my PB is pretty set on a blower being the "best" way to get strong jet action. If I ask him to omit the blower and put the intake at the back of the deck, I have no recourse (and no airline to the equipment pad) if I'm not satisfied with the jet action.

The plan calls for 5x 10gpm Waterways Poly Storm Jets using their install tees on a loop. 2.5" plumbing for water between spa and pump. Not sure what he's planning on using for the air intake line.

 

[mas985]

#1 would having the air intake that close cause excessive sucking/gurgling noises with the jets running?

My air intake is about 10' from the spa but you can't really hear it because the spa bubbles make so much noise. However, you can hear it if you are standing next to it. The intake is point away from the pool area so it really isn't that noticeable.

#2 my PB is pretty set on a blower being the "best" way to get strong jet action.

Water has 800x the density of air so that what you feel from the spa jets is the water, not the air. The air breaks up the stream to create a massaging effect. The blower is mainly there to blow the water out of the pipe so that air can flow. Too much air can ruin the effect as well if water is splashing out of the spa. Plus blowers are quite loud even at the pad.

You will probably be ok with a HL at the spa without a check valve. Given the slope is upward from there, the water should clear out fine if it should go over the loop.

 

[chemillion]

My above ground spa was only built with a Hartford loop, no check valve on the air line. The pipe runs maybe 20ft back to the equipment pad with no blower attached. My spa never has trouble getting enough air and the jets are plenty powerful enough with my IntelliFlo set only to 2500RPM for SPA Mode. I suppose if I went all the way up to full speed (3450RPM), I could probably blow off everyone's bathing suits....hmmmmm, now there's an idea

@JoyfulNoise do you have an opening on the top of your hartford loop or holes where it can draw atmospheric air in?
I'm getting water jets in the spa, but no air bubbling action (its not blow out air bubbles). Hartford loop (about 12 ft away from spa with elevation of the top 1.5 ft higher than water level) & venturi also was plumbed by the pool plumber.

 

[mas985]

No, there is not supposed to be any air holes in a Hartford loop. The loop is in the air line which on one side connects to the air inlets for the spa jets and on the other side connects to the air port near the pad or someplace else. Do you know where your air port may be?

 

[chemillion]

No, there is not supposed to be any air holes in a Hartford loop. The loop is in the air line which on one side connects to the air inlets for the spa jets and on the other side connects to the air port near the pad or someplace else. Do you know where your air port may be?

Hi @mas985 . Maybe what I call the part of the Hartford loop is mistaken. The highest point of the air loop (12 ft away from spa) which I call the horseshoe had no ports or holes for atmospheric air to be sucked in.
the Venturi’s are plumb in right at the discharge of the spa jet nozzles.
No holes existed on my horseshoe, but once drilled 2 holes 1/8” diameter on top to allow air to enter, that fixed the problem!

 

[mas985]

No holes existed on my horseshoe, but once drilled 2 holes 1/8” diameter on top to allow air to enter, that fixed the problem!

That just means the real air port is blocked somewhere. Post a picture of your equipment pad. My bet is the air port is located there somewhere.

BTW, the "horseshoe" is the Hartford loop and should not have any holes in it.

 

[chemillion]

That just means the real air port is blocked somewhere. Post a picture of your equipment pad. My bet is the air port is located there somewhere.

BTW, the "horseshoe" is the Hartford loop and should not have any holes in it.

what does the air port for the hartford loop look like at the equipment pad?
The spa pump spinning the water around is in a closed loop with no way to draw air in which I know we don’t want air in the pump.

 

[mas985]

I can't see much in that picture. I need a full pad picture. But an air port (Hartford loop or without one) is just an open ended pipe. Sometimes people will cap it to prevent the air flow. Sometimes there is an air blower installed on the line.