Acrylic Spa Insulation
Full foam hot tubs are not ideal for Canadian climates. The idea works great in California where almost every hot tub is engineered, designed and manufactured. In colder climates hot tubs can be susceptible to damage from freezing unless preventative measures are taken.
Shown here is the correct insulation method for acrylic hot tubs. This allows for a heat barrier greater than 99% efficient while retaining full access for service and repairs.
Plumbing connections and the jets themselves need periodic service and replacement and encapsulating them in foam is a short sighted approach to spa construction.
Insulated Spas Still Freeze
The equipment used in hot tubs is highly inclined to freeze during power shortages. Without the heating element on, and with the circulation pump not moving water, the pipes located at the equipment is the first to freeze. The equipment on almost every spa available is located in a non-insulated area. The water currently in the pipes, once static, will begin to freeze very quickly. A few hours at typical Canadian February weather is more than enough to begin a chain of events that often requires replacement of the tub.
The smaller pipes will freeze first and the ice will spread rapidly throughout the lines. In most cases, and especially in full foam hot tubs the insulation actually works against the anti-freezing properties of the spa. A full foam tub actually contains the heat away from the lines. This means that the shell will hold the heat for an extended period of time.
Full Foam Tubs Are Inclined To Freeze
Though the shell will remain warm, the plumbing lines encased in foam are vulnerable to encroaching ice that develops in the equipment compartment. Some tubs have the pumps and heater under a set of stairs, some have them underside the skirt of the hot tub in an uninsulated area.
Shown here are non structural cracks in the acrylic finish on a hot tub. Cracks like this very rarely allow water to escape the hot tub and are more often a reflection of the interior finish condition.
As a contractor, and using a basic understanding of thermodynamics, it is clear to me that insulating the equipment is critically important. Pressure testing and leak detection on any hot tub, and foam filled hot tubs most especially, is just an absolute horror.
The Importance Of Where The Pump Is Located
For concrete hot tubs I prefer to remotely locate the equipment inside the house or heated pool shed for a number of different reasons. Ultimately this is a problem that I do not need to worry about with concrete spas, but acrylic spas all have the equipment located on or in the unit itself.
The pump should be located inside the pump cabinet with insulation surrounding the cabinet.
There should be no insulating barrier between the pump and the shell however as this allows the heat generated by the pump operation to absorb through the shell and into the spa water.
The Best Cold Weather Insulation
The ultimate in ideal design is to insulate the outside perimeter of the cabinet and locate the pump and heater inside the insulated cabinet. Additionally no insulation barrier should be used on or around the tub to allow the heat energy to readily transfer from the water to the equipment area. I could not recommend any of my clients to buy a tub that would almost certainly fail during something as likely as a power failure in the winter.Canadian Products For Canadian Climates
Fortunately there is a Canadian manufacturer that build hot tubs for cold climates and they incorporate this perimeter insulation method. The same company that offers the lifetime shell guarantee. At this point I knew that I had found the company that I would endorse to my acrylic spa clients, however I needed to complete my research to ensure that I was not overlooking something.This is especially true of the equipment which has been the Achilles heel of many hot tub companies. Faulty, poor quality and under engineered components plagued the early generations of acrylic spas through the 1990's. The heating elements specifically have been, and continue to be problematic throughout the industry.
Proceed to the section that deals with Spa Pumps, Filters & Heaters