Convection loop hot tub system

Abstract

There is provided a portable spa pool or hot tub system which includes a tub suitable for human bathing, and a water heating unit capable of burning one or more fuels. The water heating unit is situated adjacent to the tub and connected to the tub through an upper and a lower piping means, the arrangement forming a convection circulation loop. The tub is optionally circular, and when empty capable of being lifted and carried by two persons. Optionally the tub is double skinned and of a rigid plastics material with insulation between the two layers of plastic.

1 . A portable spa pool or hot tub system comprising: 
 a tub suitable for human bathing, and    a water heating unit capable of burning a fuel selected from the group consisting of: solid fuel, diesel, other petroleum product, and gas; said unit being situated and adjacent to said tub and connected to said tub through an upper and a lower piping means arranged such that water heated in the water heating unit rises into the tub via the upper piping means and is replaced by cooler water from the tub via the lower piping means, the arrangement forming a convection circulation loop.    
   
   
       2 . A system as claimed in  claim 1  wherein said tub has a circular side wall.  
   
   
       3 . A system as claimed in either  claim 1  wherein said tub is constructed as a double skinned tub, with an insulating material between the skins.  
   
   
       4 . A system as claimed in  claim 3  wherein the skins of the tub are of a plastic material.  
   
   
       5 . A system as claimed in  claim 4  wherein the plastic material is polyethylene.  
   
   
       6 . A system as claimed in  claim 3  wherein the insulating material is a foamed polyurethane.  
   
   
       7 . The system as claimed in  claim 1  wherein the weight of the tub is such that two persons of average strength can lift and carry said tub, when empty.  
   
   
       8 . The system as claimed in  claim 1  wherein the rigidity of the tub is imparted to the tub by use of a water-impermeable material and the tub constructed in compartments which are capable of being inflated.  
   
   
       9 . A portable spa pool or hot tub system as claimed in  claim 1  wherein the water heater comprises a water jacket and a combustion chamber, the combustion chamber comprising a flame baffle plate and an ancillary air delivery means providing oxygenated heated air to the rear of the combustion chamber.  
   
   
       10 . A portable spa pool or hot tub system as claimed in  claim 1  wherein the water heater further comprises a primary access door and a secondary access door, the secondary door being rotatable about the longitudinal axis of the water heater.  
   
   
       11  A portable spa pool or hot tub system as claimed in  claim 9  wherein the ancillary air delivery means comprises a tube located through a hole in the primary access door.  
   
   
       12 . A portable spa pool or hot tub system as claimed in  claim 1  wherein said water heater further comprises a flue, said flue having an outer guard and a fly ash screen within a cowl at the upper end of the flue.  
   
   
       13 . A portable spa pool or hot tub system as claimed in any one of claims  9  wherein the inner surface of the combustion chamber is corrugated.  
   
   
       14 . A tub when used in a portable spa pool or hot tub system wherein the system comprises a water heating unit capable of burning a fuel selected from the group consisting of: solid fuel, diesel, other petroleum product, and gas; said unit being situated and adjacent to said tub and connected to said tub through an upper and a lower piping means arranged such that water heated in the water heating unit rises into the tub via the upper piping means and is replaced by cooler water from the tub via the lower piping means, the arrangement forming a convection circulation loop.