Check system cooling capacity

Check system cooling capacity as follows: − Allow system to operate for at least 15 minutes − Measure water pressure drop between water-in and water-out test plugs at heat pump. (Use same instrument to measure both to reduce error). − Measure entering water temperature at water-in test plug. − Using manufacturer's performance data, determine the water flow rate (gallons per minute) and the cooling capacity of the installation using the measured pressure drop and the measured entering water temperature. − Determine cooling capacity by using the following formula:  Btuh = (h2 - h1) x 4.5 x CFM  h1 = heat content of air from Enthalpy Table corresponding to supply air wet bulb temperature.
h2 = heat content of air from Enthalpy Table corresponding to return air wet bulb temperature.
At supply air outlet and inlet indoors record wet bulb and dry bulb temperatures.  
4.5 = air properties constant
CFM = Cubic feet per minute air calculated, from funnel, temperature rise, or return air method  
(From Enthalpy Table record heat content values that correspond to supply and return air wet bulb temperatures, h1 and h2, respectively)
− Verify that system capacity is + 10 percent of the equipment manufacturer's rating at the test conditions.
Direct Exchange Ground Source Heat Pump Inspection Procedures
Inspector shall verify the direct exchange ground source heat pump (DXGS) and duct system(s) adhere to installation standards. (See Installation Standards for certain sections that do not apply.) In addition, inspector shall do the following: • Verify the distances between the compressor and the ground coil and compressor to air handling blower unit as required by DXGS manufacturer.  Both vertical height and total line distance shall be within limits as specified by manufacturer.  Insure all linesets, both vapor and liquid, are insulated with rubatex, or similar insulation non-corrosive to copper. • Determine system heating capacity.  System inspection should never be conducted within 48 hours of completion of soaker hose operation, and should not be conducted within one week of completio