Questions about DIY Install of Mini-Splits - Page 4

woody · 01-27-14, 09:53 PM

Ok.....don't read this post...I screwed up some numbers and deleted

Cave Junction, OR 97523

Good insulation
550sq. ft. Should be about 12000 BTU

woody · 01-27-14, 09:59 PM

Just ordered one of these Thermal Leak Detectors. Price was right and it should come in handy:

Black Decker Thermal Leak Detector TLD100 | eBay

woody · 01-28-14, 04:44 PM

made a signature with my heating info. just checking to see if it posted....

MN Renovator · 01-28-14, 07:25 PM

What is the design temp for Cave Junction, OR? Which mini-split are you looking to go with?

Wondering because 12k should be more than enough for heating and I'm wondering if a 9k would be better for you. Depends on the heat pump, design temp, what 'good insulation' means, and if you need 12k of cooling due to lots of glazing.

AC_Hacker · 01-28-14, 11:57 PM

Quote:

Originally Posted by MN Renovator

What is the design temp for Cave Junction, OR? Which mini-split are you looking to go with?

Wondering because 12k should be more than enough for heating and I'm wondering if a 9k would be better for you. Depends on the heat pump, design temp, what 'good insulation' means, and if you need 12k of cooling due to lots of glazing.

Cave Junction, OR 97523
HDD@68=6945

This HDD looks curiously high, because Woody is further south than I am, but his HDD is higher.

Could be that his elevation is higher, this could account for it. Also, he might be further from the moderating effect of the ocean.

But if he really did a really good job on his insulation (walls, ceiling, floor) and infiltration, you're right, 9,000 BTU would be a good fit.

-AC

MN Renovator · 01-29-14, 07:21 AM

You size a unit using design temp, not heating degree days. It is even more important when you consider an air source heat pump because it puts out less output the colder it gets.

AC_Hacker · 01-29-14, 08:25 AM

Quote:

Originally Posted by MN Renovator

You size a unit using design temp, not heating degree days. It is even more important when you consider an air source heat pump because it puts out less output the colder it gets.

He is about 270 miles south of where I live.

We're both in the Pacific Northwest climate zone.

I have a fair idea of his situation.
'
How's the weather where you are right now?

-AC

woody · 01-30-14, 12:48 AM

so I got my numbers at:
Weather Data Depot - Your source for free heating degree day and cooling degree day reports and charts!

I used a balance point of 65 degrees.

So 2012 was:
HDD@65=5552
CDD@65=190
TDD@65=5742

And 2013 was:
HDD@65=5982
CDD@65=271
TDD@65=6253

Now my town is over an hour from the coast with a mountain in-between and our elevation is about 1,100ft.

I will be adding dual pane windows, a new solid core front door and the walls will end up with 2x6 walls. They are 2x4 right now. The ceiling has 2x6 as does the floor.
So I should be in good shape as far insulation.

Not really concerned about AC as my window mount AC works fine so the new system should work even easier.

Right now the weather is 50ish but it got down into the teens for a few weeks.
I'm at 550 sq.ft. but that may change to 600 when I extend the dinning area.

A 9000 BTU system would be great especially on the pocket book. But even a 12000 would be much better than an 18000.

So whatever info you can come up with to help would be terrific!
Thanks a lot! Woody
Oh, by the way......
This 550/600sq.ft. is my kitchen, front room and dinning room which is all open floor plan. It would also be nice to send a little heat down the hallway and in to the bathroom.... just to take the chill off. We would still use a little ele. heater when showering.

I'll post about my plan for the two bedrooms in the back later. :-)

Xringer · 01-30-14, 08:02 AM

Years ago, when I was looking at the 18,000 Sanyo, the price of the 24,000 wasn't much more.
They had about the same BTU per Watt spec, so I did a system cost per BTU calculation.
The 18,000 and the 24,000 cost per BTU was pretty close.
So, I went for the larger unit, trying to play it safe, in case my actual 'need' was higher than expected.

I didn't deliberately buy my second unit over-sized. We had a broken
outdoor unit in the garage, and my wife wanted me to buy an indoor unit,
and install it in the Den. Even over-sized? Yeah, since it was about $400.
I was able to repair the broken unit and it's still working this morning.

I was looking at the weather (City Data) for Cave Junction.
Seems like you might have a little problem with defrost cycles.

I would definitely have a little rain shelter roof over any outdoor units.

nokiasixteth · 01-30-14, 10:09 AM

What would you say best place to mount the outside unit would be ? Wall or pad ? I see X ringers is leaning on his a bit

01-27-14, 09:53 PM	#31
woody Lurking Renovator Join Date: Jan 2014 Location: Cave Junction, OR Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	Ok.....don't read this post...I screwed up some numbers and deleted Cave Junction, OR 97523 Good insulation 550sq. ft. Should be about 12000 BTU Last edited by woody; 01-30-14 at 01:06 AM..

01-27-14, 09:59 PM	#32
woody Lurking Renovator Join Date: Jan 2014 Location: Cave Junction, OR Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	Thermo Leak Detector Just ordered one of these Thermal Leak Detectors. Price was right and it should come in handy: Black Decker Thermal Leak Detector TLD100 \| eBay

01-28-14, 04:44 PM	#33
woody Lurking Renovator Join Date: Jan 2014 Location: Cave Junction, OR Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	made a signature with my heating info. just checking to see if it posted.... __________________ ---------------------------------------------- Cave Junction, OR 97523 so I got my numbers at: To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. I used a balance point of 65 degrees. So 2012 was: HDD@65=5552 CDD@65=190 TDD@65=5742 And 2013 was: HDD@65=5982 CDD@65=271 TDD@65=6253 550/600sq. ft. Should be about 12000 BTU Doing research on a 12,000 btu ductless split air system To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. ----------------------------------------------

01-30-14, 12:48 AM	#38
woody Lurking Renovator Join Date: Jan 2014 Location: Cave Junction, OR Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	more info so I got my numbers at: Weather Data Depot - Your source for free heating degree day and cooling degree day reports and charts! I used a balance point of 65 degrees. So 2012 was: HDD@65=5552 CDD@65=190 TDD@65=5742 And 2013 was: HDD@65=5982 CDD@65=271 TDD@65=6253 Now my town is over an hour from the coast with a mountain in-between and our elevation is about 1,100ft. I will be adding dual pane windows, a new solid core front door and the walls will end up with 2x6 walls. They are 2x4 right now. The ceiling has 2x6 as does the floor. So I should be in good shape as far insulation. Not really concerned about AC as my window mount AC works fine so the new system should work even easier. Right now the weather is 50ish but it got down into the teens for a few weeks. I'm at 550 sq.ft. but that may change to 600 when I extend the dinning area. A 9000 BTU system would be great especially on the pocket book. But even a 12000 would be much better than an 18000. So whatever info you can come up with to help would be terrific! Thanks a lot! Woody Oh, by the way...... This 550/600sq.ft. is my kitchen, front room and dinning room which is all open floor plan. It would also be nice to send a little heat down the hallway and in to the bathroom.... just to take the chill off. We would still use a little ele. heater when showering. I'll post about my plan for the two bedrooms in the back later. :-) __________________ ---------------------------------------------- Cave Junction, OR 97523 so I got my numbers at: To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. I used a balance point of 65 degrees. So 2012 was: HDD@65=5552 CDD@65=190 TDD@65=5742 And 2013 was: HDD@65=5982 CDD@65=271 TDD@65=6253 550/600sq. ft. Should be about 12000 BTU Doing research on a 12,000 btu ductless split air system To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. ---------------------------------------------- Last edited by woody; 01-30-14 at 12:54 AM..

01-30-14, 08:02 AM	#39
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Years ago, when I was looking at the 18,000 Sanyo, the price of the 24,000 wasn't much more. They had about the same BTU per Watt spec, so I did a system cost per BTU calculation. The 18,000 and the 24,000 cost per BTU was pretty close. So, I went for the larger unit, trying to play it safe, in case my actual 'need' was higher than expected. I didn't deliberately buy my second unit over-sized. We had a broken outdoor unit in the garage, and my wife wanted me to buy an indoor unit, and install it in the Den. Even over-sized? Yeah, since it was about $400. I was able to repair the broken unit and it's still working this morning. I was looking at the weather (City Data) for Cave Junction. Seems like you might have a little problem with defrost cycles. I would definitely have a little rain shelter roof over any outdoor units. Attached Thumbnails __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

01-28-14, 07:25 PM	#34
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	What is the design temp for Cave Junction, OR? Which mini-split are you looking to go with? Wondering because 12k should be more than enough for heating and I'm wondering if a 9k would be better for you. Depends on the heat pump, design temp, what 'good insulation' means, and if you need 12k of cooling due to lots of glazing.

01-29-14, 07:21 AM	#36
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	You size a unit using design temp, not heating degree days. It is even more important when you consider an air source heat pump because it puts out less output the colder it gets.

01-30-14, 10:09 AM	#40
nokiasixteth Journeyman EcoRenovator Join Date: Jan 2014 Location: Earth Posts: 348 Thanks: 43 Thanked 14 Times in 13 Posts	What would you say best place to mount the outside unit would be ? Wall or pad ? I see X ringers is leaning on his a bit