Everyone in that house - even the dogs - died from carbon monoxide poisoning. (Paid Link): https://geni.us/u8faW 12/2 Romex, 50 ft - This costs a lot less on Amazon: (Paid Link): https://geni.us/RnFT2 12/2 Romex, 100 ft - This costs a lot less on Amazon: (Paid Link): https://geni.us/jjUS2Q Set of Adjustable Wrenches (Paid Link): https://geni.us/mzmvj Electrical Tape - 6 Pack (Paid Link): https://geni.us/ilmuQ3J Forstner Bit Set - I used a 1 3/8 on the outside of the shop (Paid Link): https://geni.us/323sZ Klein 11-in-1 Electrical Screwdriver - I LOVE this thing! Marco Related Professionals This is pretty straight forward, there is a usb adaptor that gets plugged into the back of the front panel. With a small system, you may be able to draw power from a nearby underloaded 20-amp circuit. Refrigerant lines that are too long will compromise a systems performance. Place the back half of the channel behind the line set, plumb it and anchor it to the wall with self-tapping screws. However, you'll need to tap the next panel into place, which can be impossible without some help. Installation requires a qualified contractor. Once the concrete started to set up a bit, I troweled it smooth. Copyright 2023 This Old House Ventures, LLC. Since my line was mostly ran on the interior of the building I needed to insulate it to make sure the line didnt sweat. (Paid Link): https://geni.us/B49USF Please note that this is a 3 CFM pump, as opposed to the 5 CFM pump below. 5 CFM Vacuum Pump (Paid Link): https://geni.us/sIP8bYm Manifold Gauge Set (Paid Link): https://geni.us/O1HRDfZ Adapter from Gauge to Condenser (Paid Link): https://geni.us/M0ntsrl Wall Mount Bracket - Good (Paid Link): https://geni.us/99qpC1u Wall Mount Bracket - Better (Paid Link): https://geni.us/VTym Wall Mount Bracket - Best (Paid Link): https://geni.us/RGv9wMK 3/4 Auger Bit for Drilling Studs (Paid Link): https://geni.us/u4JWa6 2 1/8 Hole Saw (Paid Link): https://geni.us/0f7nL Klein Wire Stripper - Like I Use in the Video (Paid Link): https://geni.us/NUF0b Irwin Wire Cutter (Paid Link): https://geni.us/9XCrj0 Nylon Blue - Not required but helpful (Paid Link): https://geni.us/qIqAA Drill Bit Extension for drilling through the wall (Paid Link): https://geni.us/Aumx AC Disconnect Box (Paid Home Depot Link): homedepot.sjv.io/3PMW1d 14/2 Romex, 25 ft - This costs a lot less on Amazon! Location, Location, Location!- Mini-split outdoor units are compact; they can be located far away from noise sensitive areas. Flare nuts are also used to join these lines to the ones on the indoor unit. How to Hang Drywall Drywall contractor Paul Landry's step-by-step method for installing rock. I feel like installing a mini split is a little like learning to mud drywall. Some offer heating as well as cooling, and some include multiple evaporators to serve multiple rooms. Without poly beneath the drywall, water vapor hits the drywall and diffuses through to the drier (in summer) indoor air. In fact, many municipalities now require a bona fide load calculation to ensure the contractor has done their due diligence in determining a correctly sized mini-split system. A high-velocity, mini-duct HVAC system can bring an old house up to date with minimal damage to its historic fabric. (Paid Link): https://geni.us/DohdC7 14/2 Romex, 50 ft - This costs a lot less on Amazon: (Paid Link): https://geni.us/kqBMzAO 14/2 Romex, 100 ft - This costs a lot less on Amazon: (Paid Link): https://geni.us/t5wv 12/2 Romex, 25 ft - This costs a lot less on Amazon! Mini splits can be ducted to multiple spaces or ductless. Most outdoor units are shipped with a refrigerant charge, where an additional refrigerant charge may not be needed at all; a function of the refrigerant line lengths. In the winter, heat is scavenged from the outside and pushed back into the house. Flip up the front panel to expose it and plug it in. 100% recommended. Cost $8 to $10 per -inch x 48-foot sheet Estimated Time 6 to 8 hours The line set and 4-conductor wire pass through a sleeve to the interior. Roy, backing up a bit, I *believe* you can order the indoor unit with or without pre-attached lines, and for new construction you would want it without. I feel like installing a mini split is a little like learning to mud drywall. free estimates. For residential purposes, expect to spend about $2,500 on the unit and professional installation, on average. Venting outside on the roof The best way to vent outside on the roof is to have an outdoor unit. Scan this QR code to download the app now. All rights reserved. However, with all my insulation/rainscreen whatnot, those sleeves . Generally it will cost around $400-$500 to re-plaster the wall. Check out our pricing page to learn more about how much we charge for HVAC services and contact us if you live in the Phoenix area and would like a quote. But that's the risk you run when you skip an inspection. The 119-pound unit can be mounted on brackets fastened to the wall, as shown, or bolted to concrete blocks resting on . Fully submerge the sponge in water and squeeze out the excess. The installation was fast and easy because of the special line set. . CALL FOR QUOTE: 1.855.920.1857 Its common for Mini-Split manufacturers to combined power wiring with communications wire within a single cable. The head units can be installed on the floor, on a wall, or the ceiling. Too often, a location the contractor has in mind may vary from what the homeowner had expected, which can result in a less-than-harmonious situation. Installing a Mini Split is totally doable, but there are several things that all of the other videos gloss over. Very few brick-and-mortar stores carry DIY systems, so online shopping may be your only option. (Paid Link): https://geni.us/NL41eT Basic Pipe Cutter with Reamer (Paid Link): https://geni.us/AngXexA 1/2 WHIP (Paid Link): https://geni.us/uuL3ec5 IRWIN Vice Grips (Paid Link): https://geni.us/qwFf9 15 Amp Double Pole Breaker (Paid Link): https://geni.us/ue6D2E 20 Amp Double Pole Breaker (Paid Link): https://geni.us/rhSjH 25 Amp Double Pole Breaker (Paid Link): https://geni.us/OKlUix5 30 Amp Double Pole Breaker (Paid Link): https://geni.us/UiyTJn6 Elbow (EMT Set Screw Conduit Body) (Paid Link): https://geni.us/PQsfM 3/4 EMT Insulated Compression Connectors (Paid Link): https://geni.us/IJ2PTFy 3/4 EMT Pipe Straps (Paid Link): https://geni.us/GDJh Big Stretch Caulk (Paid Link): https://geni.us/6SAfO Dripless Caulk Gun (Paid Link): https://geni.us/hRY6FgS WANT TO HELP SUPPORT THIS CHANNEL? Reply. First, the mounting plate is screwed to the studs, as shown. View More. Check out this post to learn about the pros and cons of mini-split (aka ductless) air conditioners. If your project includes multiple interior units, labor rates will be much higher. This won't delete the articles you've saved, just the list. A mini-split system can be installed in a home, a garage, a cabin or a shed. Most Mini-Split manufacturers have both minimum and maximum length requirements. Step 3: Mark the Window Opening. You may need to remove a plate, depending on the model. average life of an air conditioner and how to extend it. The wiring freaked me out a little because I had never installed a breaker before and the overall process was totally new to me so I was learning as I go. After the hose is checked to make sure it drains freely, the end of the hole sleeve is sealed with silicone to prevent water infiltration. A local electrician estimated that work at about $500. 21 air conditioner maintenance and home cooling tips. A location on the east or north side of the structure maximizes cooling efficiency. Installation is another important thing to know about ceiling-mounted mini-splits. Then, nail it on through the tongue. In fact, as we mentioned, Mini-Split installation is a direct transfer of skills you already have. Yes, it can be, but it's going to be a little more difficult that a normal DIY installation. A solid mounting area is needed for the outdoor unit. This is a TRUE, STEP BY STEP tutorial, baby. You must be a magazine subscriber to access this feature. The truth of the matter is, oversized equipment can result in a shortened equipment lifespan with erratic temperature and humidity control in the conditioned space. A 2.5kw Fujitsu split system fully installed in this situation: $2195 including GST, plus $400-$500 . Tap the block until the board slips into place. Victor Gomez is the Vice President of Technical Support and Aftermarket for Fujitsu General America. Installing a mini split 100% on your own can be done with the new DIY system from MR COOL. As far as I know it's perfectly legal to install a pre-charged mini-split. Also, did you know you can get tons of projects plans from all around the web when you follow us on FacebookandPinterest! There are no pros to hanging doors before drywall. However, they tend to be more expensive than other types of air handlers. During this step, youll likely need to use your torque wrench for connecting the pipe joint. The complete source for building, designing, and remodeling green homes. Why? Summary. Even if the existing wiring meets the electrical requirements for the proposed Mini-Split outdoor unit, its still a good practice to propose new wiring for both indoor and outdoor units. By accepting all cookies, you agree to our use of cookies to deliver and maintain our services and site, improve the quality of Reddit, personalize Reddit content and advertising, and measure the effectiveness of advertising. Some units like Fujitsu , have rear spacing for the lines in order to be able to connect to the line sets The condenser needs a level surface to rest on. Mini-split air conditioners, of course, dont use ducts so youll avoid this added cost. Finish the hole by drilling from the outside. There is no wall insulation yet. The average cost for ductless mini split air conditioning installation costs between $2,100 to $8,000. But the reason you install the drywall after the finished flooring is that the amount of humidity that taping and finishing drywall will create will wreck havoc on your finish materials. Power then runs from the disconnect to the condenser. Then, the mounting bracket was leveled and screwed to the plywood and studs. (Paid Link): https://geni.us/HP1QJ UPDATE! Ensure the condenser has the recommended clearance from walls and bushes. If you dont feel comfortable doing this, by all means, hire a professional. Some mini-splits include an easy-install line set, but most dont. Some molly bolts have teeth on the head that dig into the drywall, so make sure that you hammer it in all the way so that these teeth can do their job. There will be a huge difference in heating an insulated cabin compared to one with no drywall and just exterior sheathing. Cable running alongside the line set powers the evaporator. Just like the wiring, its tempting to reuse the line-set, especially in a situation where Home Owners Association by-laws may forbid exposed lines. Cause I take pride in my work over putting a dollar in my pocket. screened. This feature has been temporarily disabled during the beta site preview. 100-200 sq feet: 6000-7000 BTU (0.5 ton) 200-400 sq feet: We are no longer supporting IE (Internet Explorer) as we strive to provide site experiences for browsers that support new web standards and security practices. In the steps below, youll see that installation is mostly basic DIY stuff: measuring, drilling holes, driving screws Usually the biggest challenge is running power to the system. Once they are tighten down you can then remove the caps on the side of the lines to expose an allen wrench key that gets turned until it stops to release the refrigerant in the lines and pressurize the system.This is the part of the system the differentiates it from other mini-splits. Dap, install the door casing after sheetrocking is up and, ideally, after a coat of primer is on the walls. The fabric sleeve covering the line set isnt attractive or easy to keep clean. : https://youtu.be/ShhQmxUCtUI Top 3 Reasons Your Dryer Isn't Drying Your Clothes: https://youtu.be/QD3CL-_vu5M How Do P-Traps Work? If a thermostat (aka remote) is to be mounted on the wall for sensing the room temperature locally, it should be mounted on an inside wall, approximately 5 to 5 feet above the floor. Often, an installation manual is as much of a legal document as it is a technical reference, thus all cautions and warnings must be in here to for your personal safety. Our line set also included cable to power the evaporator and a drain line to carry condensation outside. How Much Does It Cost To Install A Ductless AC The cost of installing a ductless air conditioner will depend on the area to be covered. My attention to detail and doing the job the correct way. Check out the full project video below and dont forget to subscribe on YouTubeso you wont miss future videos! The existing line-set will likely be too large or too small, and the designated line size MUST BE (again, not a suggestion) used. I have no mechanical equipment to install, as I am planing to install a Mini-split to heat and cool. The line set hole must slope slightly downward to the outside so condensate from the evaporator can drain outside. This unit should go in a shaded location outside the house where it can have at least 4 inches of clearance behind it and 20 inches of clearance above it and in front of it. Most of them have the condensor charged, and you have to draw vacuum on the line sets before opening them up. Make sure this area of the wall is free of wires, pipes and ducts that would interfere with making a hole for the line set. If any of it is perplexing, theres no shame in scheduling for an AC Installation In Phoenix, Arizona, and having a professional do the work for you. By submitting your email, you agree to our. Measure the width of the blind mechanism (the rectangular box at the top of the blind), subtract it from the width of your window's opening, and divide by two. To select the right size mini-split, calculate the heat loss of the room. We are no longer supporting IE (Internet Explorer), Do not Sell or Share My Personal Information. Do not Sell or Share My Personal Information. If the gap is deep, put painters tape on the vinyl, fill with low expansion windows and door foam in a can. This piece was made slightly smaller than the footprint of the unit so that when drywall is installed it would fit right behind it. Cut with a hole saw from inside, move aside any insulation and inspect the wall cavity for obstructions. By installing a sheet of poly there, you cut off that drying mechanism and water that finds its way into walls can stay there longer and do more damage. 2. Mini-Split system installation falls within the direct category of air conditioning installation. It is possible to cut out the HVAC guys and install your own mini-split then you are in the right place. Luckily there is a big unit sitting on top of the paw prints.Another option is to attach a mounting bracket to the side of the building. However, since we have access to the walls and have some dead space behind the unit to route the excess lines we were able to have the lines exit the building right where they need to be. The house gets quite humid and I'm going to leave the wood out to acclimate for a few days. The higher the number, the greater the cooling capacity. We recommend our users to update the browser. PHM. On one hand, you have multi-zone units, which segment your home into various regions and can handle several air handlers. This is a crucial step; inappropriately sized air conditioners can cause airflow issues and other undesirable effects. Once you run through the steps in the app youll have the unit connect to your wifi which will allow you to set up schedules, monitor the required maintenance, and enable follow me mode which make you unit aware if you are in the building or not and heat or cool accordingly. After the install, I was amazed by just how easy it was. The indoor units can be mounted on the wall, ceiling, or floor, and they blow cool air into the room directly. Luckily, we still had access to all the interior walls so we pulled a 10 AWG, 3 conductor wire with ground from the panel, through the interior walls to the location we were going to install the outdoor unit. Lastly, youll need to tie the wire into the panel. I'm wondering how common it is to run the tubes down through the wall. 1) It shows the screw holes to be used on the left and right side of the installation plate. A plastic channel screwed to the siding hides the lines, condensate hose, and control wire. Answer (1 of 12): All good answers. When installing a mini-split air conditioner's interior unit, refer to its manual. Ceiling-mounted units are called ceiling cassettes and offer a sleek, discreet design. Become a GBA Prime member and get full access to GBA articles, enyclopedia, videos, CAD library, and more. Connect the control wire to the back of your indoor unit. Theyre one of the easiest and cheapest types of air conditioners to install if your home doesnt have existing ductwork. Once you've got the job done, you know enough to do the job. Next, connect the refrigerant and drainage tubes. During my initial research into mini splits I came to the conclusion that it would cost around $3000-4000 to get my shop set up. If your customers wish is to conceal the outdoor unit, they can certainly do so, with shrubs or even an equipment screen, gate, etc. By rejecting non-essential cookies, Reddit may still use certain cookies to ensure the proper functionality of our platform. Variable capacity- Mini-splits are typically DC inverter driven. That makes sense - blocking - but I don't understand how the line-set connections can be made. You must be a magazine subscriber to access this feature. Drill a hole in the wall for the condensate line if you haven't yet. Hang the doors after painting, after hard flooring, and before carpeting. Efficiency- Mini-splits are highly engineered systems which offer attractive operating efficiencies, in many instances, eligible for utility company rebates. How is a mini-split installed in new construction? Strength of wall to hold the AC The indoor unit of split AC must be installed on a wall strong enough to hold the unit's weight. That was $1500-2000 for the unit and another $1000-2000 for install. I found a whole Vacuum Pump/Gauge/Adapter Kit for way less money! You can also reach out to independent companies, which will perform a comprehensive load calculation for you. Installing ducts can add as much as $3,300 to the overall cost, on average. The house gets quite humid and Im going to leave the wood out to acclimate for a few days. A comprehensive load calculation is the foundation of all mini-split systems success. It shouldn't be to hard to get a rough heat loss number for a small cabin. The unit then mounts to the plate. Just ask the Sisson family: Starting around April each year . Obviously, I'm missing something! Your next step in the ductless air conditioner installation process is to work on your external unit. Then go inside and set the temperature using the handheld controller. As a result, new homeowners only need to install the mini split indoor and outdoor units. So, can a mini-split be installed on an inside wall? by Scott Gibson Skill 1 5Easy The sheets are heavy and a bit unwieldy, especially when covering the ceiling. The system is then ready to heat and cool. In some cases there may be an existing line-set (the copper line that connect the indoor unit(s) to the outdoor). Mini-Split system installation falls within the direct category of air conditioning installation. There are plenty of YouTube videos showing how to do this, even by professional installers. Repeat until the ceiling is complete. Most people who actually own the property and plan on staying for a while will choose this option. Central Heating, Central A/C, All of your heating & cooling needs. Request a quote. Once you get the breaker in you can then replace the face of the panel and flip the main breaker back on. SSSHHHHH! At 45 inches long, drywall shims are the perfect length because they are the same length as the width of a sheet of drywall or half of an 8-foot length. Basic models start around $150 and have simple functions that allow you to select a cooling level and set the unit to . Your IP: 208.113.162.235, Requested URL: www.jlconline.com/photos/minisplit-installation-on-an-interior-wall, User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.4 Mobile/15E148 Safari/604.1. Peace. This took about six 80lb bags of concrete. My concern is that I plan on getting a mini split down the road and the temperature change might cause the new wood floors to contract and leave gaps. Once you've decided on which unit to get, the first thing to do is to prepare and install the indoor unit. A gauge manifold and a vacuum pump are hooked up to the refrigerant lines to detect leaks and dry the lines as refrigerant is pumped into them. Thats an abridged version of the process but its the gist of it. You can also call customer service at 1-888-JHARDIE for your closest sales representative. There is a white connecter and a ground wire that are used to do so.The power to the outdoor unit from the 30 amp disconnect is ran using a preassembled liquid tight conduit. This is 2X4 construction, sheetrock, about a 6 run. Right now, you can save $325 on a new HVAC . Within that white sleeve there is a black electrical line that runs back to the indoor unit. Install the bracket at your preferred location. Carefully uncoil the line set from the back of the evaporator. Although, literally whisper quiet, units which are located too closely to where the customer is going to be most often may result in objectionable noise. Even then, rules vary depending on the refrigerant and your jurisdiction. To install one of these, drill a hole with the same diameter as the molly bolt. Reddit and its partners use cookies and similar technologies to provide you with a better experience. However, with all my insulation/rainscreen whatnot, those sleeves are too short. Mini-split heat pumps are comprised of an outdoor heat pump and one or more indoor air handlers. And avoid installing the unit so it blows air directly on the customer or occupant of the room. In either sense, shims are cut perfectly to size for working with full sheets of drywall. The mini split air conditioners are usually 24 inches high and 26 inches wide, with a depth of around 8 inches. Rub the coarse side against the drywall in a circular motion, making sure to work into the edges so all areas are smooth. You should choose a spot to install the unit that meets these criteria: You will typically need to install the bracket first using your anchors and screws. As such, it's important to ensure that your . Before powering up, inspect the refrigerant lines for kinks and verify the electrical connections. It's really no different than running range wire or PEX tubing in a wall. You can place it on your roof or an outside wall. I am not a licensed electrician and dont claim to be. The air conditioning unit will function better if one installs it away from direct sunlight, preferably in an . Plus learn the average life of an air conditioner and how to extend it. Sometimes in a remodel you can run 1/4" or 3/8" rock over the old wall, but it's not ideal. We decided to pour our own concrete pad for the unit which was 2ft x 4ft. Drill your hole at a slight downward angle, pop a piece of PVC through, use a marker to cut pvc to length, use tape on the inside to hold it in place, seal outside if you can get to it, install head. Condensate traps may be required in gravity type drains, depending upon the location of the drain (before or after the blower) as well when prescribed by local code. They are "split" between two spaces. Begin by drilling a pilot hole from inside to outside. Minisplit Installation on an Interior Wall. Then, all thats left is the ground wire that gets connected to the metal plate below the connections. Sale. With a little effort you can save yourself a ton of money by installing this unit on your own. Just use the remote control. The walls are all angles, and have a chase for all of the refrigerant lines, drain, and wiring for both the mini-split and the wiring for the house in that area. Solar friendly- Due to very low power requirements, mini-splits are an ideal complement to Net Zero Energy homes, or any home using renewable power. The whole process, from purchasing the right supplies to finalizing the installation, can take roughly two days if youre installing lots of indoor evaporators. Cold Weather With an assistant outside, feed the line set through the hole. Ventilating dehumidifier to complement mini splits? Every mini split installation needs the following criteria met: Pictured: Mark Pauletti of Arctic Mechanical, in Port Chester, New York, uses the remote to check the airflow from the indoor unit. In the summer, the heat is extracted from the air in the house and dumped outside, making it cold. This is an example of how we installed the 36k Btu bundle in our detached workshop, the Rogue HQ. J. But generally speaking, you can expect to spend between $1,500 to $2,500 per ton of cooling capacity. This can be a higher initial cost then buying and installing a central AC system, but because a mini split runs significantly . A single air handler can heat or cool up to 1,000 square feet, depending on the climate and system size. Then hang the evaporator on the mounting bracket. . Afterwards gently re-hang it on it's bracket. Next, create a roughly 2-inch hole (or whatever size the manual has identified) next to the bracket. Remove the drain hose from the indoor unit by following the steps dictated on the unit's instruction manual. We first removed the top soil, then framed out the pad and leveled the frame, followed by mixing the concrete, pouring into the frame and using a board to screed it flat, filling all the low spots. Before an indoor unit is permanently installed, clarify and verify with the homeowner, exactly where the [indoor] unit is to be located. Hit the \"Join\" button or head to https://www.youtube.com/channel/UCPKAKrjoMz7POptCloy7AIQ/joinSupport us on Patreon: https://www.patreon.com/lrn2diy LRN2DIY SHIRTS, HOODIES \u0026 MORE https://lrn2diy-merch.creator-spring.com MY FILMING GEAR Heres everything I use to film my videos, including cameras, lights, microphones and more: https://kit.co/nilsynils/my-filming-gear SOCIAL MEDIA Facebook: https://www.facebook.com/lrn2diyInstagram: https://www.instagram.com/lrn2diy/Twitter: https://www.twitter.com/lrn2diyTikTok: https://www.tiktok.com/@lrn2diy MORE DIY GOODNESS Check out our many projects and plans at https://lrn2diy.com WANT TO LEARN MORE ABOUT 3D PRINTING? Here again, the manufacturers Installation Manual will provide the prescribed pressure test details, so dont bypass this critical step! When cured, if any has come out of the crack, gently remove it with a knife. Step 2. (This of course, after the leak has been fixed) The majority of leaks can be traced back to less than ideal flare connections made during installation. Trust our experts to replace, repair or maintain your heating and cooling systems. Follow the next fifteen steps to hang drywall. The best way to install an outdoor mini-split is through a DIY installation. You only need to nail on the tongue side; the previous board will hold the groove side in place. Most mini-split manufacturers will require a pressure test in the 500 to 600 PSIG range, up to a 24-hour duration. If load calculations are not within your realm of expertise, many equipment manufacturers will provide their own design software, or you may consider numerous industry approved software programs, which will help you correctly determine the required heating and cooling capacities. This unit should go in a shaded location outside the house where it can have at least 4 inches of clearance behind it and 20 inches of clearance above it and in front of it. Once youve got the job done, you know enough to do the job. Heres How to Replace it, Dry Clothes Faster with a Dryer Duct Booster, AC Noise: Tips for Fixing Noisy Air Conditioners, Allergies: Filtering Out Pollen With Furnace Filters, New Kitchen Venting: How to Install a Kitchen Fan Vent, We are no longer supporting IE (Internet Explorer), ClimateRight 12,000-BTU heating and cooling system, We Tried Amazons Best-Selling Cordless String Trimmer, What to Do Within the First Year After Moving Into Your New Home. Unfortunately, the dog walked over it not once, but twice. Dont just guess; an undersized system wont keep up, and an oversized system will cycle on and off too frequently, shortening the condensers service life. Un-hang it from it's bracket and swing it gently over to sit on top of a ladder while the door is re-worked. Next, youll need these tools and supplies: Well also note that this process is much easier if you have a second pair of hands to assist you with holding things in place while you install the unit. Cookie Notice To heat or cool an average living room alone with a square footage of 350 square feet, a 18,000 BTU ductless AC unit with a 21 SEER rating would end up costing around $1,500 for the unit only and around $3,800 for complete installation. These types of non-textbook details must be thought out before a unit is installed. 2023 The Taunton Press, Inc. All rights reserved. A new window AC unit costs about $150 to $800. Get the latest This Old House news, trusted tips, tricks, and DIY Smarts projects from our expertsstraight to your inbox. He has a degree in Electrical Engineering and a passion for all things HVAC. Several websites simplify these calculations. Installing a Solid Base for the Outdoor Unit A solid mounting area is needed for the outdoor unit. Ideally the outside unit is close by, so the lines can be run down and through studs to an exit point through the sheathing and siding. In Maryland, the summers are brutally hot. Minisplit mounting question.