The MacBone Series CHV24, 24,000 BTU/hr., cooling, heating, dehumidifying and pressurizing unit, is a vertical or “side-mounted”, unitary, or self-contained unit, with a closed, precharged refrigeration circuit, driven by a single, integral, hydraulic motor. Heating is derived from the circulation of hot engine coolant, engine oil or hydraulic oil through the unit. Heating capacity is 30,000 BTU/Hr. at a fluid flow rate of 1.5 GPM at 140° F. The design concept is derived from the need for an air conditioning unit for industrial applications where the unit can be quickly removed for service without involving the sealed refrigeration circuit. Cooling is provided by a thermostatically controlled automotive type compressor, using refrigerant 134A. The condenser fan and evaporator blower share a common shaft, driven by the hydraulic motor with sufficient power to produce substantial condenser air flow even with a filter on the outside coil, thus insuring reliable performance even in a heavily dust laden environment. Substantial power delivered to the inside air blower also assures delivery of full system capacity under all conditions. Induction of about 5% outside air through a washable filter provides some cab pressurization to exclude dust and other larger particle contaminants from entering the cab environment. The addition of a MacBone external cab pressurizer, model P150-1 or P150-V, will increase outside air filtration and air volume to about 14%. Two places are provided to quickly install the P150-1 or the P150-V with the remote mount filter canister.
Hydraulic drive input is usually, but not necessarily, from a pump driven by the vehicle's engine and utilizing the vehicle's hydraulic reservoir. Required flow is a constant 10 GPM at a variable pressure from 600 to 1400 PSIG. System pressure relief, provided by the installer, should be set at 1650 PSI. Electrical input of 3.5 amps, at 12 or 24 VDC, is used only to activate the compressor clutch. There are no electrically driven fans or blowers in the MacBone design. All CHV24-8 models accept either 12 or 24 V.D.C.
For the CHV24 series units, a required subbase with shock mounts is supplied with the unit. All units, measure 37.5” wide (horizontal dimension) by 26.5” high and protrude 12.75” from the surface on which they are mounted. There is no protrusion inside the space being cooled. The total weight is 188 pounds. Hydraulic lines are #8, supply and return, up to 40'. The motor has an external case drain to protect its shaft seal and this drain is intended to be returned directly to the hydraulic tank by a #6 line. Seven 1/2 inch SAE mounting bolts provide for quick removal for service or replacement. The dual V belt drive system has an automatic tensioner and operates in a closed, ventilated area. Recommended operating time before overhaul is 6000 hours. Recommended unit life is four overhaul cycles. Note, however, that at the end of the 2006 season, we are finding units four to five years old in need of drive belts only. We also note that four overhaul cycles will not be the limit.