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DIY ductless heating systems

3.7K views 24 replies 12 participants last post by  omarijarvis  
#1 Ā·
Well I'm getting to the point of needing to install a heating and cooling system in the 900 square foot vacation house I'm building and originally planned and a standard electric furnace but now I want a duct less system. I have absolutely no experience in HVAC install and turning to the general public for opinions,will be installing it myself so shoot away with any thoughts or things I should look out for i m looking for easy install with a duct in living/dining room and one for each bedroom .
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#3 Ā·
I bought several Mitsubishis from AC Wholesalers in Florida. They shipped free and have several name brands available. I got a 14,000 BTU in our 1500 sq' mobile home, a 18,000 BTU in our old two story farm house and helped my buddy get a 22,000 BTU for his large A frame. All are working great. The one we have in our mobile home is 10 years old. I had to replace the board once. Fairly easy to clean. Have fun.
 
#8 Ā·
I put in two Diakin mini splits in my house and love them so far. Only a couple years experience. I saved roughly 50% of what a contractor installed system would have cost.

I bought the equipment from Vinje and Son in Portland. They have a DIY program that helps you through the process. Their contractor does the final charge on the unit but I did all the rest of the work:

1) Poured pads for the outside unit and installed it.
2) Ran the wiring, installed breakers, including an outside by the unit required disconect breaker, and hooked up wiring to heat pump.
3) Installed convenience outside outlets next to the heat pump (required these days).
4) Ran the line sets (insulated copper tubing) and the outside trim to cover said line set.
5) Hung the inside registers and cut the hole through the wall for line set. I also sleeved the hole in the wall with plastic pipe and insulated with expanding foam insulation.
6) Got the necessary permits and passed inspections.

I didn't save the maximum amount available by buying on the internet but the contractor connection Vinje provides was pretty crucial IMO. When I shopped around to find a heating and cooling contractor that would do the final charging of the unit, I had no takers after multiple calls. But that was during covid times, it may be easier now.

If you have any connections to a heating and cooling contactor that could do the final charging of the heat pump, that would make it easier to just buy all the equipment on line and save $

Good luck
 
#24 Ā·
I put in two Diakin mini splits in my house and love them so far. Only a couple years experience. I saved roughly 50% of what a contractor installed system would have cost.

I bought the equipment from Vinje and Son in Portland. They have a DIY program that helps you through the process. Their contractor does the final charge on the unit but I did all the rest of the work:

1) Poured pads for the outside unit and installed it.
2) Ran the wiring, installed breakers, including an outside by the unit required disconect breaker, and hooked up wiring to heat pump.
3) Installed convenience outside outlets next to the heat pump (required these days).
4) Ran the line sets (insulated copper tubing) and the outside trim to cover said line set.
5) Hung the inside registers and cut the hole through the wall for line set. I also sleeved the hole in the wall with plastic pipe and insulated with expanding foam insulation.
6) Got the necessary permits and passed inspections.

I didn't save the maximum amount available by buying on the internet but the contractor connection Vinje provides was pretty crucial IMO. When I shopped around to find a heating and cooling contractor that would do the final charging of the unit, I had no takers after multiple calls. But that was during covid times, it may be easier now.

If you have any connections to a heating and cooling contactor that could do the final charging of the heat pump, that would make it easier to just buy all the equipment on line and save $

Good luck
I second using Vinje and Son. I used them to convert 2 houses from oil to gas, and they are THE DIY guys.
 
#12 Ā·
The problem with Mr Cool is they have low HSPF which means they are not very efficient to generate heat and they won't work very well once outside temperature gets much below 40 F.

If you go with a 'cold climate' mini split, many of them will continue to generate heat with outdoor temps as low as -15f. So you will never need to use that expensive auxiliary heat cadets and you will save money due to higher efficiency. So compare HSPF when looking at various brands: that is the heating efficiency. I had a Mr Cool and it was terrible at generating heat below about 40f outdoors. I now have a unit with HSPF of 12 and it does great at low temps like in the teens, never need auxiliary heat.

My Mr Cool would blow cold air into the room when it had to defrost. Really disliked it. The Panasonic high HSPF unit recircs the warm air for defrost without blowing cold air in your house so you don't even realize it is defrosting.
 
#18 Ā·
The problem with Mr Cool is they have low HSPF which means they are not very efficient to generate heat and they won't work very well once outside temperature gets much below 40 F.

If you go with a 'cold climate' mini split, many of them will continue to generate heat with outdoor temps as low as -15f. So you will never need to use that expensive auxiliary heat cadets and you will save money due to higher efficiency. So compare HSPF when looking at various brands: that is the heating efficiency. I had a Mr Cool and it was terrible at generating heat below about 40f outdoors. I now have a unit with HSPF of 12 and it does great at low temps like in the teens, never need auxiliary heat.

My Mr Cool would blow cold air into the room when it had to defrost. Really disliked it. The Panasonic high HSPF unit recircs the warm air for defrost without blowing cold air in your house so you don't even realize it is defrosting.

The question in the thread was about DIY installs. In my search I didn't find many options. I'm sure there are lots of professional installs options that are more efficient but would cost 2-4 time more. Is there a better DIY option than Mr Cool?
 
#14 Ā·
I actually have a 12000 btu Klimaire. According to the supplier it's the same as a Mr. Cool with a different label. I installed it a year and a half ago. We have been really happy with it. It's in our vacation place. An early 80s 14x52 singlewide. I don't feel like I installed it in an ideal place, because there is a sliding door where I would have liked to install it and to put it on that end it would have been facing down a wall that has a couch there. We are still pretty impressed with how comfortable the unit keeps the place. It was low to mid 30s over the weekend and we had no issue keeping the house over 70 degrees. Never felt it blow cold air once. Keeps the house comfy on the hottest days also.

That said, I can see why people would want to invest in Panasonic, Mitsubishi, etc. If your ok with spending more $s.

I see where some of the Mitsubishis have a hspf of 13.5.
 
#15 Ā·
HSPF is fairly easy to understand: a value of 12 is 20% more efficient than 10, so that will save you 20% on your heating electric bill. The higher HSPF units tend to also be capable of working at colder temperatures. You can find high HSPF units (11.5 and up) for about the same price as the Mr Cool, such as the Senville. I have Panasonics in the house and cabin, a Senville in the shop. When purchasing, find the highest HSPF unit you can afford and keep in mind that, like insulation, paying a little extra now is money in the bank down the road. As you know, it's amazing how inexpensive it is to heat with a mini split.
 
#19 Ā· (Edited)
If you stick with a 16 foot line set, you can self-install just about any mini split since they all come precharged with R410A and require no extra charge. You will need common tools, a vacuum pump, optional nitrogen tank and optional micron vacuum gauge to do a self-install of any mini split. Some brands come precharged for up to a 25 foot lineset: check the specs of any you are considering to determine the precharged maximum and minimum lineset lengths (without having to add more refrigerant).

The Mr Cool DIY version saves you the purchase of a $140 vacuum pump kit off Amazon, but Mr Cool charges about $400 more for their DIY version than their standard version mini split. So the economics of the Mr Cool DIY version never made sense to me.

When you self-install, there are many hours of work regardless of brand: mount indoor and outdoor units, run 120V or 240 V wiring (both use same 12 awg wire typically for 12000 BTU or smaller), run the control cable, run the line set copper tubing, and figure out a downhill drain setup to drain the condensate in a/c mode.

I have done 9 self-installs. After everything is mounted, fastened and wired, I prefer to pressure test using a nitrogen tank and high pressure gauge, then vacuum down and check for leaks using a micron gauge. You can skip the pressure test and micron gauge with Mr Cool DIY but the pressure check and vacuum measurement get skipped by many self-installers, regardless of brand. I found a leak on one of my installs, so the pressure and vacuum tests have been worth it for me.

Yes the professional installs are 2x or more expensive: that is mostly labor for all that mechanical and electrical install. You can buy a good quality high HSPF (11.5 and up) mini split for the same price or less than Mr Cool DIY (check out Senville at sylvane.com), and end up with a low cost install, a system that saves you money every month, and a unit that works at very low outdoor temperatures.

If you care about a warranty, you will need to have the final pressure test and vacuum done by a certified HVAC technician: I had that step done professionally for $400 on my first mini split. All the rest of my 9 installs I have done everything myself and forego the warranty. All the mini split companies cancel warranty if you do the final line set testing step yourself. Since Mr Cool charges about $400 more for their DIY version than their standard version (roughly the cost of hiring a pro to do the line set test after you've done the rest of the install yourself), their DIY product essentially relies on FUD (Fear, Uncertainty and Doubt) of new users: a common marketing scheme.
 
#20 Ā·
Good posts as usual Positize!
When I did mine I looked at a ton of options. At the time, Mr. Cool and many others were really hard to come by. I looked at the Senville, Blueridge, and even the major brands like Daikin, Mitsubishi, etc. I settled on the Klimaire and have been very happy with it. It was a few hundred bucks cheaper than a Mr. Cool and I applied for an Amazon card and saved another $175.

I considered doing exactly as you talked about. Buying the pump etc and doing it all myself and forgoing the warranty. If another install comes up sometime I may do that. I'll just have to weigh it all out. They really arent that hard to install. A bit time consuming. Especially on the first one. But after doing one and getting the experience I have no doubt the next one would be way quicker and easier.
 
#21 Ā·
I would still consider a Mr Cool unit if you are a Costco member. They are $100s less than HD or Lowes.

I wasn't interested in purchasing special tools and equipment or learning how to vacuum down and pressure test, which is really a professional install. I was only going to do it once for my place on the coast. Mr Cool can be installed with not much more than a drill, hole saw and wrench. If you feel comfortable learning something new, that's great.

Good luck getting a contractor to show up if you are located in a remote location like my place on the coast. These days its not an option to try to get someone to show up to do anything. Simple was better for me.

Mr Cool has a good reputation and is well established been around for years. They will be around to back the product and have been good to deal with so far. Been happy with the purchase. I've seen some of the other companies that offered DIY come and go. Home Depot offered a DIY mini split from ClimateRite but quit selling it presumably because was junk from a crappy company.
 
#22 Ā·
When I was researching a mini-split for my houes I read many a post where some tried DIYing and non-DIY unit and having no experience in flaring copper, leaked out all the refrigerant that was charge in the unit and ended up with a $500 + bill to have an HVAC professional redo it and recharge it. The only drawback from MrCool, IMO, is the plug-n-play line sets come in fixed lengths 10', 16', 25'. Whichever one you use, if you don't need exactly what you get then you have to coil up the extra and tuck it behind the unit. Not the cleanest looking install and a negative if that really bothers you. I'll post up pix of my install later.
 
#23 Ā· (Edited)
Good point about learning to flare copper tubing. It can be tricky. The simple solution is to measure the lineset length you need and buy one that is already flared with fittings on both ends: pre-built linesets are readily available in all kinds of lengths. With that approach, you have the moral equivalent of a Mr Cool DIY, with just the added step of vacuuming down the lineset. Lineset length does not have to be dead on, so I always plan to have a horizontal L or U curve near the outdoor unit so my measurements don't have to be exact. With a little measuring and planning, there is no reason to fear lineset installation: select your mini split for its price, efficiency, and features, not its lineset. The difficulty and time is all the work to mount everything, run wiring, drains, etc - which you have to deal with in any case.
 
#25 Ā· (Edited)
wow I don't know anything about installing heating systems, but I just wanted to say that your project looks really wonderful
hope you have great time by building this vacation house and have enough money for it. if you have any troubles with recording your financial transactions, you can look paycom reviews, maybe you'll find something useful
but I hope one day I'll also be able to do something beautiful like you:love::love::love: