I'm a handy guy and can do pretty much anything around the house that I put my mind to. Assuming I can handle the part of the install that is outside (the concrete pad, the hole in the crawlspace wall, the electric), is it realistic for a handy homeowner to run flexible ductwork throughout a small (1000 sq. foot) house and hook the whole thing up? What are the most likely mistakes a newbie would make in this process? If you're willing to blur the line between homeowner and HVAC tech, sure. If this is a split system, hooking up the linesets, purging the lines with compressed nitrogen, pumping it down, measuring the vacuum, adjusting the charge, and ensuring that the system is leak-free are all likely to be the most challenging parts. These tasks require specialized tools and knowledge. You can certainly get the tools and acquire the knowledge, but once you do that, you're basically as good as an HVAC guy, many of whom don't actually know how to do this stuff very well themselves.

Duct design is also its own huge field. If you just haphazardly run flex duct off a main trunk, you're getting a pretty typical professional residential job. But if you're doing it yourself, you have the opportunity to fabricate rigid sheet metal ducting, seal all the seams and gaps perfectly, design the entire system to be balanced, have enough returns, etc. This information would all be found in ASHRAE Manual D (D for Duct). Keep those ducts out of the attic! A crawlspace duct install is fine as long as there's a sealed vapor barrier over the dirt and the crawlspace walls are insulated.Browse other questions tagged hvac diy-vs-pro or ask your own question.How to Install an A/C Package Unit An A/C package unit involves an entire air conditioner unit with all the necessary equipment included to hook it up to a building ventilation system. All the owner needs to do involves preparing a cement bed for the unit to sit on and arranging the actual connection work. Because the units come pre-packaged, they make great appliances for mobile residences as well as roof-top A/C needs.

With a bit of help from an electrician, the unit can be set up and running within a few hours. Locate the ventilation intake hookup on the outside of the building the A/C unit will be added to. Determine the best location where to sit the A/C unit. Build a wood frame with 2x4 wood beams in the form of a square large enough to fit the A/C unit shape. Mix some quick-setting concrete in a bucket with water. Lay down rebar in the wood frame area. Pour the concrete into the frame and smooth it out. Let the concrete dry. Go to a local hardware/appliance store and purchase an A/C package unit. Transport it with a truck back to your location. Load the unit off the truck and onto an equipment dolly. Wheel it over to the cement pad that is now dry and cured. Place the unit on the cement pad. Unwrap the shipping packaging and expand the wiring and connectors for the unit. Hire an electrician to wire and connect the A/C unit to the building’s electrical grid. Look for the A/C air hosing.

Connect this to the building’s ventilation intake conduit. ac unit has iceSeal the hose to the building with vent duct tape and sealant.car head unit ac power Call an A/C technician to perform the final check on the unit and charge it with refrigerant. new ac window unitWith the A/C technician present, test the system. Enjoy the working A/C unit once the installation is finished. Lift with a partner when positioning the A/C unit off of the truck or onto the cement pad. This will prevent suffering a serious lifting injury to your back. Do not fiddle or try to force position any of the A/C unit coils. These parts can easily break, allowing refrigerant to escape immediately. Such a repair can then be very costly. AC 4 Life: Self Contained Air Conditioning Package Unit