Spa Jets Explained

www.rickrobinsonhomes.com

SPA Jets Explained

Consider a simple spa jet. Spa Jets have 3 main connections – water in, air in, and a water and air mixture outlet. The water is pushed into the jet by pressure from the pump and flows through and comes out the front. This is how the air gets mixed into the pressurized water stream that we will be discussing.

How Spa Jets Work

The air gets mixed into the pressurized water by use of a venturi inside the jet. The venturi effect happens at the tip of the orifice which is a small hole inside the jet that all the incoming water gets pushed through.

To understand the venturi effect you have to first understand the way fluid acts inside a pipe. If we reduce the size of a pipe with fluid moving through it, the velocity (speed) of the water increases, but the pressure in the pipe decreases. So if we have spa water flowing through a 2” pipe and we reduce the size to 1.5” for part of the run, the water in the 1.5” section moves faster but at a lower pressure.

If you look inside a spa jet they all have a reduction in the internal plumbing size, we call this reduced size section the “orifice”. The most common size of the hole in the orifice is 5/16” of an inch. This means that we reduce the incoming water feed that was lets say 1” pipe, and we force all this water through a hole just over a 1/4” wide.

This causes a section of the water to travel at a higher velocity and at a much lower pressure. This low pressure at the tip of the jet orifice is lower than the pressure of the air in the atmosphere outside. Since the outside air is a higher pressure than the water at the tip of the orifice, air gets pushed into the water stream at the tip of the orifice and mixed into the water. This water and air mixture then flows out of the front giving us the jet action we are all familiar.

What goes wrong with Spa jets?

Most complaints about spa jets have to do with them no longer mixing air properly. Customers will report that the jets are “broken” or not working, they will also sometimes refer to the pump “not being as strong as it used to be”, or even talk about the air controls or the air blower being broken.
Jet malfunctions usually lead to weak jets or jets with no air in them at all, but they can also lead to water shooting out of the air controls or a the jet sucking water in instead of blowing water out.
Almost all jet problems are centered around the orifice. I will list some of these troubles below:


Insufficient water input – if the pump is not delivering enough water to the jets they may not develop a low enough pressure inside to suck air from the outside world effectively. This can cause jets to be weak or have no air at all. The diameter of the hole in the orifice determines how much water a jet needs to work properly. If you have insufficient water input it can mean that you have a dirty filter cartridge, an obstruction in the pump impeller, or even an undersized pump for the amount of jets you have.

Too much water input – if the pump is over sized it can cause back pressure inside the jet after the orifice, this can cause the jet to not draw air correctly by applying pressure inside the jet where the low pressure is supposed to be formed. This back pressure is between the orifice and the eyeball at the front of the jet where the water and air mixture come out. Sometimes this problem can be relieved by increasing the size of the eyeball in the front. I have seen this problem most often in gunite spas.
Another problem with the older style gunite spa jets is the length can be an issue. With the orifice tees set back inside the wall the length of the pipe between the orifice and the front eyeball can vary greatly. The length of the pipe run itself can cause back pressure with long piping runs through walls it is often necessary up size the eyeballs, or even reduce the size of the orifice opening in the back of the jet and reduce the water flow. Modern design gunite jets move the orifice to the front and eliminate this issue.

Gasket/O-ring Problems – many modern jets have the orifice inside a removable jet internal. On these jets there is often a gasket or o-ring that separates the water pressure area from the low pressure air suction area. When this separation breaks down the high water pressure can leak over to the low pressure air side making the jet not draw air correctly or at all. If this leakage gets severe enough it can also cause water to come out of the air controls.

Plugged Orifice – a small obstruction can get lodged it the orifice obstructing the water flow. Running a screwdriver or other long, thin object through the orifice will often knock it loose, this works best with the jet pump running to help push the object out. If the the object is too large, you will sometimes need to remove the orifice and manually pull the object out of the jet.
Note that other jets may be affected from a single obstruction. The air line on the plugged jet is usually hooked to the air lines from other spa jets. The neighboring jets will still be drawing a suction on those air lines. Sometimes this will cause the surrounding jets to suck water through the air line backwards through the plugged jet, causing the plugged jet to be pulling water into the eyeball instead of outward. This usually only happens on inground spas where the air intake is far away, or for any reason, easier for one jet to pull water from another jet than to pull air from the air intake.

This Article is courtesy of Spa Parts Plus

Until Next Time....

So you need a new spa cover. Where do you start?

www.rickrobinsonhomes.com

If your spa cover has gotten so heavy that it takes two people and a fork lift to open, then it is time to replace that cover. Where do you start?

Spa covers are made from a Styrofoam core inside with a 2 or 3 mil vapor wrap around the core then reinforced at the fold points. Once the wrap is penetrated, it will then start to absorb moisture from underneath. This is why they get so heavy. It is just easier to replace it then try and dry it out and fix it. Any repair would only be temporary anyway.

They come in several colors to match what ever décor you have and they have upgrades available if you would like it to be thicker or support more weight. Most have a 3" to 2" taper, like the pitch of a roof so that the rain can easily run off the cover and not pool in the center. They typically have a radius corner edge, although there are plenty out there with 90 degree corners or cut corners as well.

When you are ready to order a new spa cover there are some measurements you will need to know to get a proper fit.

• measure the widest width of the spa from outside edge to outside edge of the acrylic. Do not measure the old cover as this could have warped or swollen from age or water absorption.
• measure the longest width from outside edge to outside edge of the acrylic just like before.
• measure the length of the skirt (or flap) material that hangs down from the cover edge, you want to be sure that all acrylic will be covered when in the closed position.

Now very important, if you have a radius corner on your cover you will need to supply this measurement as well. Take two rulers, place the rulers up against the side edge of the cover where the turn of the radius first starts to turn inward, place the other ruler on the opposite side of the same radius corner, note where the two rulers intersect...now measure back from where the radius corner starts to turn  to where the rulers intersect, this number is the arc of the radius. Watch this great video on how to measure a radius corner on a spa.

Lastly you will need to show which way the fold of your cover goes in relation to the topside controls. Does it open front to back? Some models will fold left to right like a book. Once you have all this information it will be easy to place your order for a new cover online and it could you a lot of money.

I hope this helped some of you. Until Next Time...

Why is my spa cover getting so heavy?

Why is my spa cover getting so heavy? I'll tell you why.


This topic goes along with one of my other blogs. "Think You Need A New Spa Cover".


If you need to go to the gym to be able to lift your cover there is a problem. Lets talk about why a spa cover gets so heavy.


The cover manufactures tell us that while their covers are very durable they are not meant for excessive snow loads, weight bearing etc. What does that mean??


Those of us in the cold snowy climates know what excessive snow can weigh. While an inch of snow is not a problem 6-12 inches would be. The snow will freeze and get even heavier. Spa cover's are only supported at the outer edges. Therefore there is no support in the middle of the cover. So you have to be diligent about not putting anything heavy on the cover.

The cover is there to keep the heat in and the rain and snow out, not to be a shelf for your flower pots, or a bed for your animals: When anything too heavy rests on the vinyl it can crack the inner core of the cover. This is a foam core with a thin protective wrap around it and when that wrap is penetrated(broken from weight) the exposed foam starts to absorb the moisture of the water from underneath or on top. As this absorption continues the foam gets heavier and heavier until you can't lift up the cover.




If you have a cover lifter installed on your spa, this can do major damage to the lifter. I have seen the wind blow open a waterlogged cover and snap the metal lifter arms and tear the spa skirting right off the spa.






So what have we learned so far? A spa cover has an average life span of 3-5 years. Do not use your spa cover as a storage spot and do not let snow build up on top. You can extend this life with just a little care and maintenance.


Every 6 months or so you should clean the vinyl and add a new coating of protectant to give your cover the protection from the sun that it needs. So if you notice that your cover is a lot heavier than it used to be, you probably should be thinking of replacing it before more damage is done.






Until next time......

If you need a crane to open your spa cover...

Rick the Spa guy

If you need a crane to open your spa cover... I think you need a new one. Here are a few tips that you should know.

Spa covers have a life of about 3-5 years.

One of the first things you should look for is the taper of the cover. This is where the cover looks like the roof of a house to allow rain to run off the cover and not pool in the middle. 

Most replacement covers out there offer a 3"-2" taper. This is good because it will do what it's designed to do. A 4"-3" taper is better but usually offered at an additional cost.


The next thing should be the density of the foam core inside the vinyl. I recommend a 2 lb Density foam core. 

Also you want steam stoppers, these will prevent the steam from escaping and lowering the water level prematurely. Most times you will have a good selection of colors to choose from if you want to match your house color or patio set. In most cases if you purchase on-line you will have to supply the spa dimensions to the company. 

This should be done with the cover off the spa.(Always measure the spa itself NEVER the old cover. The old cover has probably taken on water and swelled up and if you use those measurements the new cover will not fit correctly.


If your spa has Radius corners you will need to supply that dimension as well. This is easy to figure out. Get 2 rulers lay each ruler against the outside edge of the acrylic where the radius just starts to make it's turn, extend both rulers outward until they intersect each other. 

Now measure from where the acrylic just starts to turn in to the radius and measure out to where the rulers intersect and that measurement will be the radius of your spa corner.


The last thing I want to mention is that after you have purchased your new spa cover you should be cleaning the vinyl about every 6 months and using a spa cover cleaner and protection, this will recoat the UV protection and help shield the vinyl from the suns rays. 

A cover lifter will also improve the life of your new cover and make it a lot easier for you to open and close. I will go over these options in another post.


Oh yeah, and if you want the straps to line up on the new cover to the old locks you will need to give them those dimensions as well, It sounds worse than it is...Its easy... Hope this helps .......


Until next time.......

Why Is My Spa Cover Getting So Heavy?



Rick the Spa Guy



Why is my spa cover getting so heavy? I'll tell you why.

This topic goes along with one of my other blogs. "Think You Need A New Spa Cover".

 If you need to go to the gym to be able to lift your cover there is a problem. Lets talk about why a spa cover gets so heavy.

The cover manufactures  tell us that while their covers are very durable they are not meant for excessive snow loads, weight bearing etc. What does that mean??

Those of us in the cold snowy climates know what excessive snow can weigh. While an inch of snow is not a problem 6-12 inches would be. The snow will freeze and get even heavier. Spa cover's are only supported at the outer edges. Therefore there is no support in the middle of the cover. So you have to be diligent about not putting anything heavy on the cover.

 The cover is there to keep the heat in and the rain and snow out, not to be a shelf for your flower pots, or a bed for your animals: When anything too heavy rests on the vinyl it can crack the inner core of the cover. This is a foam core with a thin protective wrap around it and when that wrap is penetrated(broken from weight) the exposed foam starts to absorb the moisture of the water from underneath or on top. As this absorption continues the foam gets heavier and heavier until you can't lift up the cover.

 If you have a cover lifter installed on your spa, this can do major damage to the lifter. I have seen the wind blow open a waterlogged cover and snap the metal lifter arms and tear the spa skirting right off the spa.

So what have we learned so far? A spa cover has an average life span of 3-5 years. Do not use your spa cover as a storage spot and do not let snow build up on top. You can extend this life with just a little care and maintenance.


Every 6 months or so you should clean the vinyl and add a new coating of protectant to give your cover the protection from the sun that it needs. So if you notice that your cover is a lot heavier than it used to be, you probably should be thinking of replacing it before more damage is done.

Until next time......