"Full Foam" Design Flaws

We at Pacific Spa Sales affectionately call our "full foam" competitors "poor value spas".***Click here for some more "full foam" info***

"Full Foam Insulation" has been described elsewhere on this web site. To summarize briefly: A weak low cost plastic shell is filled with sprayed in foam plastic to strengthen the shell. Below are some of the engineering consequences of this design.

One poor value design concept creates a chain reaction of poor design consequences.

Seven or more other design changes occur because of this poor value design.
1. When the small pump housing box (containing the motors, heater and electronic controller) overheats, the entire system is automatically shut off to prevent heat damage to the motors and controller. Heat buildup can happen quickly on a hot day as electric motors can put out a lot of heat. Shutting down means no filtering and no jets.

2. Because equipment overheating is a real problem in this design, the designers decided to "fix" the problem. They started installing very small pumps that don't put out much heat. The very small circ pump is usually called the "tiny might" or some similar name and circulates only 6 gallons of water per minute for filtering. Less heat buildup certainly, but, insufficient filtering.

3. Because the larger therapy pumps put out even more waste heat, the designers again "fixed" the problem. You guessed it! Smaller therapy pumps were installed. Usually, less than 2.5 continuous HP each. One very popular spa has a 1.65 HP single speed pump for the entire spa. This is just barely enough pump power for the jets in one seat. Clearly not enough power for an entire hot tub full of people. This is why we will talk about diverter valves next.

4. Because such small therapy pumps are used, "diverter valves" must be used to provide acceptable jet pressure in each seat. The small pumps can only power the jets on one seat at a time. Diverter valves take the entire output of the small pump and concentrate it in only one seat of the spa.

5. Two more diverter problems: One annoying problem with diverter valves is this, the spa customer must constantly manipulate 2 or 3 diverter valves to get the water flowing to the seat of their choice. It is a fact that you can't run all of the jets at the same time in a "full foam/diverter valve" design. The other problem is that these valves are "restrictive". They are narrow and add a sharp 90 degree turn to the spa plumbing. This restrictive valve further cuts down on the limited power available from the small pump motor. The spa manufacturer has not done the consumer a favor by using this design.

6. Because small motors and pumps are used, the manufacturers save big on the cost of building the spas. Smaller pumps are cheaper to install than larger pumps. If you look at the high prices of these "poor value" spas you will see that the cost savings are not passed on to consumers. The manufacturer simply makes more money on each spa sale.
7. "Blowers" or what Haven Spas calls "Turbo air" are almost never found on these "poor value" spas. Turbo Air provides a special air pump that blows air into the spa through special air injectors and also special ports on the jets to boost the jet therapy effect. The air is drawn in from the warm air insulation chamber inside the spa cabinet. It is great when you really have sore muscles! Adding turbo air to the jets almost doubles the massage hydrotherapy coming from the jets. It is an absolutely wonderful feature to have on a hot tub. It is really a shame not to have turbo air on your expensive spa.

8. But, blowers or "turbo air" are left off of "poor value" spas. Remember that the "full foam" design has a very small equipment box described above. The air drawn in by the blower pump is cool atmospheric air. This colder air cools off the warm spa water as it is blown through the water. Cooling the water with the blower pump causes the 5,500 watt heater to come back on to keep the water warm. 5,500 watts!! The engineers "fixed" the problem of this design flaw by removing the blower pump. The marketing department will try hard to convince that you do not want a blower on your hot tub. They will say that it is useless and problematic. By the time you are finished talking to the salesman, he will have you convinced that you are lucky you don't have "Turbo Air"! Please re-read #7 above.

9. Again, the spa builder saves several hundred dollars by not installing a blower. The builder does not lower the price of the spa. Again, he just makes more money on the sale of each spa. This is called a high profit margin product.