The two compartments of the body must be maintained at appropriate levels for the equipment and operator. The grooming compartment will be maintained at "room" temperature during working hours. Both the working and equipment compartments will be maintained at temperatures above freezing and below equipment maximums of about 90 degrees Fahrenheit.
Insulation
To start with the entire body is highly insulated. The ceiling and doors of the body have an aluminum skin, 1.5" air space filled with injected polyurethane foam insulation and covered internally with 3/4" plywood. The walls are similar, but the outside skin is FRP; 3/8" plywood with fiberglass bonded to both sides. The floor of the body is 1 1/2" thick hardwood with insulation below. The step well of the side-entry door is also insulated. Below is a picture of a section of the wall cut out during furnace installation.
We concluded with a Carrier AirV HC 15,000 BTU rooftop unit. There seemed to be little to distinguish competitive products from manufacturers in this market. One feature which tipped the choice to the Carrier unit was the ease of interior filter removal/cleaning.
The Carrier unit has two thin strips which can be pulled out and wiped off. Coleman units required removing two thumb screws to lower the inside cover, then the removal and cleaning of foam filter material. This is a very small consideration for anyone but a dog groomer.
This cooling capacity should be more than adequate for the 500 cubic foot volume of the workspace. Some of the workspace air will be pushed into the equipment compartment to keep electronic devices there within tolerance.
This turned out to be one of the more complex physical components to design/install. We chose Atwood Mobile Products for the furnace and water heaters. Atwood has two basic furnace systems. The Excalibur systems require ductwork. Thanks to Chris Griffin at Atwood for assistance acquiring and interpreting installation requirements for the furnace. In order to guarantee proper airflow, four of the available output openings must be used and 64 square inches of return air area must be provided.
To satisfy these requirements, a duct opens directly into the grooming area under the bath tub, with a diverter to the bathroom. To provide return air, a large opening is provided high in the partition above the bathtub and a smaller opening in the bathroom. These openings make the rear, equipment area part of the return air space. Details of the installation can be seen in the equipment room plan view and rear elevation.
