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This document outlines suggested changes to the heat pump installation checkout procedure, focusing on eliminating third-party charges, enhancing evaluation methods, and ensuring system performance to meet manufacturer's specifications.
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Suggested Changes to Heat Pump Installation Checkout Procedure Baylon, Davis, Strand Ecotope, Inc. 7 June 2005 RTF Meeting Portland, OR
Installation Check Out –Suggested Changes • Eliminate third party charge evaluation requirement (Section 5.4 of PTCS specs) • Field study suggests limited problem • EWEB analysis suggests impact only in extreme cases (exact conditions unknown) • Lab tests show no significant impact until system significantly undercharged • Contractors have resisted this step or tried to short-circuit it
Suggested Changes (2) • Require an indirect evaluation that also addresses homeowner comfort (and do it in heating mode) • Measure airflow (TrueFlow preferred) – already required in Section 6.4 of RTF and PTCS specs • Measure sensible split at plenums after 15 minutes of heating operation • Calculate output and compare with mfr’s target • Require documentation of line set length and adjustments made to charge level (already mentioned in both RTF/PTCS specs) • Require documentation of operating pressures and ambient conditions
Capacity Measurement Capacity is known from temp split and airflow and can be compared with mfr’s info • Customer/utility have recourse • Installer has data to submit to mfr if system is installed to spec and is not providing expected output
Additional On Site Inspection Steps • Checklist of components (already detailed in specs) must be completed* • Accumulator (if required) • Crankcase heater (if required) • Filter dryer • Condensate pan(s)/pump • Indoor/outdoor thermostat operation must be confirmed and explained to homeowner • Timing of inspection important *could be by non-service tech with some training
Additional Considerations • ECM blower flow needs to be measured (some board settings produce marginal flow) • Cooling season evaluation of charge can be done as before • Alternate means of calculating airflow (DB matching, temperature split) are acceptable as long as they are documented