On and off for the past couple of days I've been trying to properly install a Carrier Air V rooftop A/C on my '73 Sovereign
. I've unassembled and reassembled the ceiling unit so many times now I can do it blindfolded. The two main problems I've encountered have been the compression of the exterior and interior skins (especially an aggravated deflection of the exterior skin at the rear of the 14"x14" roof opening) and not being able to attach the grille assembly to the ceiling unit due to a combination of the ceiling curvature and interior skin compression by the tightened down ceiling unit.
I've used cedar spacers between the skins and also between the ceiling and ceiling unit with some positive results, however I am still getting a bad deflection of the exterior skin to the rear of the roof opening.
Tomorrow I am getting a 16 or 14 gauge re-enforced stainless base plate fabricated to bridge the supports fore and aft of the roof opening for the rooftop unit to sit on. After I install this stainless base plate I will continue to work out the most appropriate spacer arrangement for both between the skins and between the ceiling and ceiling unit.
Two other issues I intend to address: 1) I will try to seal the gap between the straight ceiling unit grille assembly and the curved ceiling with gray open cell foam closure material, and 2) I am concerned about the negative pressure created between the inner and outer skins by the unducted routing of the return air through the roof opening where there is exposure to the insulated space between the inner and outer skins - I plan on using 2" open cell foam backer rod between the skins around the roof opening to seal this gap. If unchecked, both of these conditions will contribute to the intake of unfiltered air across the evaporator.
After the A/C unit installation is completed, then I have to lower the support bracket for the bedroom privacy curtain since the new (substantially lowered by spacers) ceiling unit has now displaced this bracket.
Despite all these minor problems along with no provision for a drip pan to drain to an internal condensate drain I am very pleased with the Carrier unit.
Does anyone else have any experience with the installation of the Carrier Air V they would care to share?