inexpensive diy mini-split install
 

hi,just joined;dont have much $;just bought small fannie mae foreclosure fixer-upper in w washington;will try el cheapo minisplit install
wish me luck
will update:)

How large is the home? Have you purchased the mini-split yet?

inexpensive diy mini-split install
 

house/cottage is about 500 sq ft but can close off 50;built 1930
I just bought a still- in- box klimaire 9000 inverter off craigslist;his plans changed so only $400.
Its w washington,mile from Columbia river, so pretty mild albeit rainy climate

Sounds like a good price.. Have you been reading up on the installs posted here?
Might take a few hours, but may save you a lot more in the long run..

el cheapo
 

yes;Ive read just about all of yours; very good.
One thing Im going to try which I think was missing: Will use heat source.probably hair dryer/blow dryer , to warm up copper lines toward end of vacuum.I suspect you and Larry David and I arent too experienced using such appliances...lol

Hey!! I use a heat gun all the time at work. (Wiring stuff).

Not sure how much good heating the lineset will do you.
Much of the air you're going to pump out, is sitting inside the indoor unit coil.
Nice and warm inside the house.

I like to vac linesets on a nice warm day.. 45F or above. :)

el cheapo
 

Now that you mention it I might even try the hair dryer at the inside coils through the outlet;I cant imagine itd do any harm since those coils are made to run hot.
I liked your idea re using some 410a as a poor mans nitrogen pressure test.I realize nitrogen would be better for several reasons but remember this is a lowball operation all the way.

Yeah, if it will hold a hard vacuum, it will probably hold pressure too.

IMHO, it's good to pressure test, even if you have great vacuum,
since a 'flare' surface will pull down tighter with vac inside.
While pressure will try to lift the flare open.
Pressure will show the finger-tight connector. :)

The only problem I can see with nitrogen pressure testing is over-doing it.
Bursting something or forcing nitrogen into the system via the service a valve.

My older system has a little leakiness in one of the valves. After it had set
for a while with a new charge, there was pressure under the valve access cap.
A little puff of gas came out when I removed the cap (to turn the valve).
To me, that was a sign to use lower pressure on the nitrogen test.
And, to insure those caps were replaced tightly.

Almost everything Ive read,both here and on other boards, is very laudatory about blue nylog as a sealant against leaks. Any comments?

I've used it and it seems like good stuff.
When applying it to a flare, I recommend putting some on both the inside and outside of the flare.
Anywhere two metal parts are going to rub each other.
I think the lube effect will allow the flare to shape itself
around the flare cone, without binding or galling on the brass.

heat sizing chart
 

Anyone know of a simple btu heat sizing chart that would involve these parameters:sq ft to be heated, temperature rise, insulation quality ?
Frankly, since Ive already got a 9000 btu inverter and know the area is about 450 sq ft. and january heat rise avg needed is about 25 degrees(W.Washington)Im mainly interested in deciding how good insulation I need.
Yes, I know about Manual J etc but this on the very low end of the heat pump hit parade. Thanks

10, 20, 40, 60 - slab, foundation wall, above grade wall, ceiling. Then think about manual J and heat pumps and other mechanicals.

How much do you need? Well, none. The Japanese use very little and have the longest life expectancy.

For the most part, the folks on this blog take energy efficiency and infiltration prevention and insulation pretty seriously.

Most of the folks here would consider insulating to state code as being the starting point, where the real fun begins... and going beyond the minimum is the whole point.

In fact, there's even a friendly energy efficiency competition going on here.

The information you have provided is insufficient to estimate anything... you probably don't realize it, but it borders on insulting in its incompleteness.

You might do better to telephone your local state energy department and ask her, or him, what the state code is for what it is you want to insulate.

Your rep will likely ask you questions about the information you did not supply in your request, above. Your rep will cheerfully do the work for you.

It's your tax dollars at work...

Good Luck,


-AC

It only gets down to 45 degrees in west washington. ...or have I found someone else who is comfortable in a house that most people would ask if the furnace was broken upon entering? At 45 degrees I didn't even run my heat when I had insulation and air sealing done the same way that other mid 80's houses were built. I've since upgraded various bits of insulation and substantially air sealed since then. If you build to todays code and you only get to 45 degrees outside, I'm not seeing you needing to go above code to use a 9k inverter heat pump.

In the long run, you'd be better off not sitting at the minimums though.

Only gets down to 45 degrees?

What part of western washington do you live in?

Even this chart for Seattle doesn't tell the whole story... it's only average and doesn't display the spikes which need to be accounted for in determining 'design temperature'.

This average temp chart for Portland (my fair city)...


...doesn't reflect the fact that the temp dropped down to the high 20's this past winter, nor does it reflect the fact that temps dropped down to 17F last winter, nor does it reflect that thirty years ago, it dropped down to 5F and stayed there for nearly a week.

How long have you lived in the Pacific North West?

Are you aware that we get periodic severe weather that comes howling down from Alaska and Canada?

You are in for some surprises, my friend!

-AC

I said that based on the OP's comment about 25 degrees indoor/outdoor differential. I may have read that wrong though. If 36 degrees out and 61 in is acceptable to the OP, then I suppose that is fine.

FWIW, I have a Manual J that says that at the absolutely coldest temperatures that a gas furnace or whatever the heating source is shouldn't be able to keep up and should sag down slightly in temperature in order to be more efficient for the majority of time that it isn't the coldest few days of the year. You'll never find an HVAC guy actually even try to explain that to anyone so they'll oversize the s*** out of everything. ...with inadequately sized ductwork sized more appropriately to the actual heat load while they are at it.

... a prioblem for fossil fuel, a big problem for vapor-compression machines.

-AC

But it still does not account for where you came up with the wacky statements about the weather?

I'd really like to know...

While you're mulling it over, HERE IS A LINK to a page with some fascinating Portland, Oregon outlier weather stories for your amusement. You can be confidant that if it got this cold in Portland, Western Washington was even worse...

-AC

"But it still does not account for where you came up with the wacky statements about the weather?
I'd really like to know..."
If this is directed at me, I just explained in my previous post that this was information based on the statement of the OP and my response was based on the graphs you provided in post 15. If this wasn't directed at me, carry on.

OK, now I get it... when you said:

You actually meant, "...the statistically average temperature for the coldest months in western washington is around 40F but variations in weather can cause spikes above and below that amount by 23F degrees (the generally assumed designed temperature for this weather shed is 17F) or more, so it is advisable to plan your heating accordingly."

Sorry, I didn't read between the lines...

-AC

Actually I misread post 11. I missed the avg part when he said 25 degree heat rise. Everything spiraled from there when I took what he said to be the 25 degree heat rise as the max heat rise required between indoor/outdoor temps. I figured maybe it was one of those coastal region pockets that never sees bad weather. I once talked to someone off of a coaster area in California that said it never really gets blisteringly hot and they rarely see snow. I figured maybe this was similar. I misread the thread. My bad. No reading between the lines was necessary, I misread a post and ran down a hill with it in that post.

Stuart; since you are in WA state, the following has a good spreadsheet that will be helpful ---plus, all the byzantine state 'legislate the value of pi' laws that you will be stuck with if you cannot avoid getting a building permit.

good luck.

WSU Extension Energy Program > Building Efficiency > Energy Code


FWIW - reading, complying, getting the permits, etc. will take (much) more effort and time than actually installing a mini-split......!!!!!

Well.finally got el cheapo mini split installed.Had to hire someone off craigslist to do some of it since been feeling a bit under the weather but total sum still very low. Tried it and to my relief/amazement it actually worked! Now to see if it maintains.The brand,Klimaire, has gotten horrible reviews lately on Amazon;mostly re support.The odd thing to me is that it has a good Toshiba compressor so I suspect the unit itself may be ok but the organization behind it is bad.One of the reviewers in fact said it seems like good engineering has been let down by bad business structure. I guess we'll see..lol

Congrads! I hope you watched the install closely, since these things can be additive. :)

It's been pretty warm around here this summer, so we are using our Sanyo units,
whenever it gets uncomfortable.. => 80% H & => 80F
It doesn't take long to get toasty indoors, when the sun is out..

Good luck with your system..

Quite isn't it.. :)

Yes,very quiet. In fact noise level is the main reason I opted for a mini-split over a window unit;Ive always been very noise sensitive I guess. fwiw I did the "hvac part" of the install ;they did the electrical and heavy work. I used a hair dryer to heat up the evap coils,a cheap vacuum pump, and used nylog blue on the flares and caps;on the other hand I used the traditional manifold gauges and pressure tested with a spritz of the 410a .I guess you might say I tried to make up for lack of funds with a bit of inventiveness. The thing is that contractors are asking $3-5 k for a basic installed unit so they made my diy decision a no-brainer.

Mine are both on right now, I'm sitting in the less than 20 feet away from them, and I don't hear anything at all.
But, when that attic fan is on, it's very noticeable.

If a large amount of units are being sold, you have to take "horrible reviews" with a grain of salt.
Since there might be thousands of happy owners who didn't write a review..

Plus, a product like this one, where people might want to do a large percentage of the work themselves,
You might get some 'pro' installers writing negative reviews, for their own personal reasons.

So far so good. Ive just used it lightly for Cooling;heating will probably be 95% of annual usage.
Fwiw..Id recommend 2 "tricks " for a low budget diy installer:1-Use Nylog blue sealant on all copper connections.Its non contaminating and pro hvac guys on internet swear by it. 2-Use a heat source such as hair dryer to warm up evap coils during vacuum;might help when using cheapo vac pump. ( Unfortunately for x-ringer hair dryer will require a new purchase...lol)

They also have Nylog for non-R410A systems.
Nylog, HVAC Gasket and Thread Sealant.mp4 - YouTube