Mini-split ductless question..

[Xringer]

It's been a about a month and it's been cold as well digger's butt.
How has that mini-split been working out on these cold days?
Have you had any problem with the outdoor unit frosting up?

Thanks,

[Nevyn]

This thread has led me to think that I should get one of these with my tax return.

Here's the situation. We have an oil furnace driving a single-pipe steam heat system (steam goes up to radiators, condenses, and uses the same pipe to return to furnace) that does a good job of keeping the house warm, but at a rather high price.

One of these units looks like it would be PERFECT for my downstairs. I could mount the compressor unit in what was a flowerbed beside the house right by the dryer vent - thus having a relatively good supply of hot air for it to work against in the cold, and the wall unit right above it in the "middle" room of the house.

There is an archway between the front room (stairs and TV) and the middle room (table and toy area) that is about 10 feet wide and 8 high. The rooms I'm looking to heat/cool with it are roughly 14' x 21' for a total of 588 sq. ft.

Is one worth it for me, living in Pennsylvania? Probably 85% of our time is spent in those two rooms, and having A/C would make the summer VERY nice.

Being able to *cheaply* heat those two rooms and leave the furnace set low would help our oil bill - but would it make a big impact? Would I save enough on heating/cooling over the next 4 years to pay for the unit?

What size unit should I go with for ~600 square feet if I were to get one?

The first 5 pictures are the two rooms to heat/cool.

Picasa Web Albums - Nevyn

[Xringer]

You need to check out some of the AC websites. Many have programs or charts to help
you size your system. My guess is about 12,000 BTU..

4 years to pay back? Right now, my oil is about $2 a gallon. When and if it goes up again,
will it stop at $4 a gallon? Or $5 ?? No one knows the payback on these things..
(Solar panels, hybrid cars etc)..


Edit:
Here's a URL with some info about BTUs needed for sq foot.
http://www.ductlesshvacsupply.com/btu-sizing.html

[Forty Two]

Mine has been running really well. No complaints- only happy with the purchase.
I never notice if its frosting up. It just shuts itself off. Its pretty easy to tell on the really cold nights that it will gradually stop working at around zero degrees.

As far as sizing- another thing to think about is this: those charts are mainly for cooling. As far as heating- it depends on your climate. When its zero degrees outside I think my hp still puts out heat, but much less.... maybe 7500 btus instead of the 12000 it is rated for. If heat is your main concern- I'd oversize. Because these are DC powered, they will throttle up and down a lot more than most of us are used to with conventional A/Cs.
My 12000 btu (15k for heat) will comfortably heat about 800-1000 sq feet with heat to spare if I use a fan to blow it downstairs. But its also running constantly as opposed to a 60k btu furnace cycling on and off. I would try one out. I'm also looking forward to the A/C as an extra benefit.
My bill depends a lot on the weather. If its really cold (below zero)- not much benefit. Above that- it makes everything more comfortable. And if I take the time to put a fan in the doorway and crank the HP it'll heat the downstairs partially as well. Your situation sounds much more ideal than mine- I'll bet it would cut your oil bill in half and probably bump the electric by $30-50 in the winter.

[Nevyn]

Thanks, that's got a lot of what I wanted to hear in it. it's rare to see temps that low here, but it does happen occasionally. I'd be mounting the compressor in front of the dryer vent, which I figure should help with air temps for it to work against a little bit. My area to heat/cool is ~588 square feet, which is kind of on the line. I'd love to oversize, but I'm also looking to minimize cost.

If it halved my oil bill then it might pay for itself by springtime. That's a MAJOR bargain! I just have to be sure to get one that is inverter powered, correct?

[Forty Two]

I would look for one that has an inverter (which will cost slightly more) and uses 410a as the refridgerant. The one I got is this one:
mini split air conditioner - ductless split system
it seemed to be the most efficient I could find. I've been happy with it so far.
It is only 120v so the install is not that hard for a DIY. You will still need someone to vacuum the lines, but craigslist is a great place to look.
Good luck!

[Xringer]

Originally Posted by Nevyn

Thanks, that's got a lot of what I wanted to hear in it. it's rare to see temps that low here, but it does happen occasionally. I'd be mounting the compressor in front of the dryer vent, which I figure should help with air temps for it to work against a little bit. My area to heat/cool is ~588 square feet, which is kind of on the line. I'd love to oversize, but I'm also looking to minimize cost.

If it halved my oil bill then it might pay for itself by springtime. That's a MAJOR bargain! I just have to be sure to get one that is inverter powered, correct?

I would make sure it's an Inverter model, and a brand name you've heard of.
I would also download the manuals and be sure the heating mode worked well, when the outdoor temps are low. IIRC, some of the Mini-splits I've seen for sale, don't publish any data below 30 deg F.



Placing the outdoor unit near the dryer vent might be asking for problems,
with little micro fibers of lint building up in the coil.


I looked at the $ price per BTU out on the Sanyo systems and found,
Sanyo Ductless Mini Split Heating and Air Conditioning
that the price per BTU for the 24,200 BTU model ($2111.00) comes in at the best rate,
about 8.723 cents per BTU.. The other sized Sanyo models range from 10 to 15 cents per BTU.

With the free stuff, it's too good of a deal for me to pass up..

FREE FREIGHT to your local FedEx Freight Terminal US Continental deliveries $129.00

FREE 20'-Interconnecting LineSet with UV Protected Wiring $219.00
FREE Service Disconnect Box and Power Whip $56.00
FREE Condenser Mounting Block Risers $37.85
FREE Wall Sleeve and 10' Drain Hose
$14.00
FREE Warranty,Technical and Installation Support Priceless


Yeah, I'm going to be ordering soon..

[Xringer]

Originally Posted by Forty Two

Mine has been running really well. No complaints- only happy with the purchase.
I never notice if its frosting up. It just shuts itself off. Its pretty easy to tell on the really cold nights that it will gradually stop working at around zero degrees.

As far as sizing- another thing to think about is this: those charts are mainly for cooling. As far as heating- it depends on your climate. When its zero degrees outside I think my hp still puts out heat, but much less.... maybe 7500 btus instead of the 12000 it is rated for. If heat is your main concern- I'd oversize. Because these are DC powered, they will throttle up and down a lot more than most of us are used to with conventional A/Cs.
My 12000 btu (15k for heat) will comfortably heat about 800-1000 sq feet with heat to spare if I use a fan to blow it downstairs. But its also running constantly as opposed to a 60k btu furnace cycling on and off. I would try one out. I'm also looking forward to the A/C as an extra benefit.
My bill depends a lot on the weather. If its really cold (below zero)- not much benefit. Above that- it makes everything more comfortable. And if I take the time to put a fan in the doorway and crank the HP it'll heat the downstairs partially as well. Your situation sounds much more ideal than mine- I'll bet it would cut your oil bill in half and probably bump the electric by $30-50 in the winter.

Thanks for the report.. That's just what I wanted to hear!
We have had a few Zero degree spells this year, but about 89% of the time,
we could have been using a mini-split.. (If we had one)!

I plan to start on the pad and pre-wiring the 220V this month.
I will be placing my order for the 24,200 BTU Sayno very soon.
We should be able to get it installed soon enough to use the heater mode,
since spring time seems far away right now..

[Xringer]

Originally Posted by Forty Two

I would look for one that has an inverter (which will cost slightly more) and uses 410a as the refridgerant. The one I got is this one:
mini split air conditioner - ductless split system
it seemed to be the most efficient I could find. I've been happy with it so far.
It is only 120v so the install is not that hard for a DIY. You will still need someone to vacuum the lines, but craigslist is a great place to look.
Good luck!

Dang! Now you got me looking at the AmcorAir 24000 deal...
It does have a 25' line set, instead of the 20' with the Sanyo kit..
Comes with a wall thermostat too. (In case I lose the remote)!
The HSPF of 9.8 is better than the Sanyo's 8.5 HSPF...
And, the price is better. Hummmmm..

[psmithrt]

42,

I know the link I left a few post back may not have stood out so here it is again.

Free Home Air Conditioning! - Save Money on Air Conditioning Bills

I realize it is a long read and the person sounds a little pompous but what he describes seems well thought out. If given the yard space and initiative I would think one could keep their outdoor unit close to it's SWEET range year round using this closed loop setup with the outdoor compressor driving it in a kind of push pull configuration.
You mention adding on another large heat pump for basement or main floor or both, are you familiar with multi splits. One of the most reputable brands sells here now and while I'm sure would cost more than your 12k unit x however many rooms, it still may offer many benefits for your additions as opposed to multi smaller units. Especially after you put in the cheaper electric supply meter you spoke of. Expensive I know but 3-4 ton from one outdoor unit and up to 8 indoor units of varying capacities.

http://www.daikinac.com/residential/...-%20Daikin.pdf

Just zone the whole system so it can condition the area your in at any time of day. Just look over the specs and see what you think. Now think about the one outdoor unit driving a closed loop earth tube system and what do you think you could save now.

Just a thought Paul