had to google ptcs Performance Tested Comfort Systems PTCS Certification is an important qualification for contractors working on HVAC systems such as furnaces, air conditioners, heat pumps, and ventilation ducts. PTCS certified contractors are trained � and held accountable through third-party inspections � to evaluate your entire house as a system when installing a new HVAC system. In many cases, you may be able to replace your existing furnace, air conditioner or heat pump with a smaller (and cheaper) unit if the installation is accompanied by air sealing, insulation, duct sealing and other efficiency measures. The program is limited to the Pacific Northwest, including Washington, Oregon, Montana and Idaho. If you live in one of those four states, you should look for the PTCS Certification when evaluating a contractor to do any HVAC work for your house. ___________________________________________________________ ok enough of that pic by pic comments: Pic 1 hard pipe supply plenum (silver) with black flex suppy duct see the failure of the duct tape? the duct tape should be removed. black jacket and insulation folded back and take off mastic sealed to hard pipe plenum. not only the take off but also the inner liner of duct to take off. let dry. insulation and jacket pulled to plenum in full contact and mastic sealed. I would use paint on mastic for the seal to the plenum and mastic tape to secure jacket to ductwrap of plenum. pic 2 & 3 see above pic 4 your vapor barrier should extend up on the walls of the crawlspace and be sealed to walls pic 4 this is where the hard duct plenum reduces to smaller size..the joints here leak also. but opening the duct wrap and mastic sealing these areas would be a LOT of work. you may want to seal major leaks first and see if performance improves before tackling the sealing of hard pipe. It is curious that the pipes seem to be insulated with batt insulation rather than pipe insulation see pink insulation wrap on pipe going thru block wall. this may be to condensing unit? so do you think you may take this job on or sub it out? if you sub it out make sure that you have duct leakage numbers before and test to get reduction numbers afte sealing. also take a look at the job in progress to make sure that mastic or mastic tapes are used. best of luck.

"I think" is not good enough unless you like to part with your money. When I have been walking around the Maryland area, not far from you, I see a lot of heat pumps. The low temp performance is steadily improving so don't depend anecdotal reports from people with units that are a few years old. The number of outside walls has nothing to do with the physics of heat pump low-temperature performance, but everything to do with heat gain and loss calculations. More outside walls = more capacity, not different type of equipment. The US DOE has work sheets to help you calculate the relative costs of operating gas heat vs. heat pumps with your current utility rates (as well as cooling costs with different equipment efficiency).

Properly installed ducts will not sweat regardless of how humid surrounding air is. One red flag in your discription is "cheap tape was used". Flex duct is best secured with Zip-ties. The linner is normally taped to boot then insulation and outside cover pulled over linner and secured with Zip-tie. If you reconnect ducts to boots,buy the special tensioning tool to pull Zip-ties tight. It sounds like conditioned air is finding it's way out of the spirial wire linner then flowing against outside cover. There might be holes in linner or linner might be disconnected from boots. Another possibility is that duct is simply not well enough insulated.

I would avoid putting the HVAC system in a closet. The best place for northern areas is the basement. I'm in the extreme south (Katy, Tx a suburb of Houston) and I tell people all the time with closet installed systems that they should consider moving it to the attic. (there are no basements here) The reason why the attic is "usually" the better place here is in most cases there is more room to access and repair the equipment. Don't put a system in thinking it will last forever. They all break at some point, the easier it is for service / replacement the better. I would also avoid "furdown" units or in the wall systems, thru the wall etc. These are mostly apartment style units and can be quite challenging to work on. I pretty much view them as "disposable" air conditioners. - When they break, buy a new one.