Through Wall Room AC/ Heat pumps?

[Xringer]

Saw this one on Ebay ($500 shipped).


Model RAC009A4HR

PTAC / Through Wall - 9,300 Btu Cooling & Heating Thru Wall Air Conditioner - Harbor Point Air Conditioners

I currently have an old hole-in-the-wall 18,000 BTU Sears Kenmoore AC (cooling only) in my Den,
so I'm thinking maybe a heat pump unit might be a might be a good replacement for the old unit.

I'm wondering if any of you folks have investigated these units and found
data about their cold weather operating range.?.

It would be nice if the range went down to at least 10deg F..

Ebay link..
9300 Btu Heat Pump Thru Wall Ductless Air Conditioner - eBay (item 260671961007 end time Mar-30-11 15:45:31 PDT)

[scottwj]

Generally, heat pumps decline in heat output as you near freezing or below outside, to the point that
electric strip heat is just as effective. Also the outside coils will be subject to icing if moisture is present.
This is mostly a property of the thermodynamics of the refrigerant.
I understand there are some heat pumps optimized for colder operation, but are not commercially common yet.

[Xringer]

Yeah, the heat output from my Sanyo Mini-split drops off as it gets colder.
I'm not sure at what point it would be equal to a plain heating element.
I think that might be down under 2 or 3 degrees F..

Normally, I don't even try to use it under 10deg F, since it's running so hard.
I just save the wear-n-tear and use the back-up heat. (Oil and/or space heaters).

If a thru-wall ASHP could pump in at least 4,000 BTU into my little 240 sqft room,
when it was down around 18 degrees F outside, that would be good enough.
That's about the 'equal' mark. (1172 watts into a space heater = 4,000 BTUh).
And of course, everything above 18F would be better.

[AC_Hacker]

Originally Posted by Xringer

I'm not sure at what point it would be equal to a plain heating element.

Here's a plot of the data that you put on the blog here.

Does this plot seem to jive with your experience?

-AC_Hacker

* * *

[Xringer]

It's really hard to say. I just have a vague 'feel' for how many BTUs are being emitted..
I know it's getting cold outside, when I see the 800-900w on the meter continuously.

Because, most of the time, it stays at 470-500w.. I think that's the power range
that pumps in enough heat, to over come the losses, when it's 20 to 30F degrees out.
When it's above 30F, it will still run at 470-500w, but will drop to 60w periodically, as the setpoint is passed.
The dang thing is so quite, it's hard to know if it went into 60w mode or not.


If it's 21C in here, and I see 600w on the meter, the outside temp is likely getting down under 20F.

I did get a reply back from the Ebay vendor.. Not good news..

Thank you, by virture of its design this doesn't work in freezing temperatures
as the split ductless does and is spec'ed only into the upper 30's. Thank you, Jeff Cole 818-437-8730

- harborpoint

[AC_Hacker]

Originally Posted by Xringer

It's really hard to say. I just have a vague 'feel' for how many BTUs are being emitted..

Have you kept good enough notes on Power Use vs Temperature to be able to do a plot of that?

-AC_Hacker

[Xringer]

Too much work to keep notes, I do enough of that on the solar stuff..

I wanted to automate some data collection.. But the dang TED doesn't work very well, since we use CFLs and dimmers..

When (or IF) I the TED working right, I can collect good power data with a PC. (leaving the setpoint at 21c 24/7)..
Then, I can use the data from the local weatherwart to complete the data set.
Climatological Data

I've got big plans and little hands..

[Xringer]

I checked out another one.. Amana AH093E35AXAA
Amana AH093E35AXAA 9200 BTU Air Conditioner Heat Pump - eBay (item 390292223049 end time Apr-25-11 12:49:31 PDT)

Ebay dealer sent me this:
The unit will switch to electric heat somewhere around 32 to 38 degrees F. Because it switches to electric heat, there is not a point where the heat pump is at 50%. I hope this helps.

- super_six_two

[gasguy]

I to have been looking to replace my energy hungry 3 PTAC units. They are 28 years old and have served us well with only 2 start capacitor replacements, DIY. They are 9800 btu heat pumps by Frederich YS series and consume about 1080 watts cooling and up to 3300 watts for heat below 40 deg. Two of them run 24/7 during the summer and winter.

I was wanting to go with the 42 inch slide in chaises for easy re-install. The best unit I found to meet my min. spec's was the GE Zonline heat pump that heats down to 25 deg. Then started looking at what was I to gain. Nothing but higher energy bills since all the PTAC's I looked at did not have DC INVERTERS. I just can not believe MFG's have not jumped into this technology for the PTAC industry.

For the last few months I have investigated the Mini Splits and found that they are the way to go for may needs and should save me about 40% or more on my energy bill.

I plan on buying two 18000 btu mini splits systems as I have read that over sizing isn't to big a deal. I really need more CFM and higher cooling/heating btu's than my old units provided, especially in heating, here in south central Texas.

Thanks, my 1st post

[Xringer]

Another member from Canyon Lake, Tx?? Welcome aboard!

If I ever moved to Texas, I most would definitely use mini-splits..
It rarely got very cold when I was a kid living in Del Rio, TX,
but when it did get down in the teens and 20s,
we just were not acclimated for cold weather!

And, we didn't have nice warm parkas, that would actually keep you warm.
I never saw a jacket with a bottom or waist strap for updrafts,
or a good wind-proof closed cuff, until I got up here and had to go outside and move snow..

No worry about getting an inverter mini split that has too many BTUhs.
The larger system will cool off or heat up the house faster, but will
throttle back down and use 300-400 watts to maintain the setpoint on most days.
And on extreme days it's going to be up to the task.
Then, throttle back to 800 or 900 watts..

Cheers,
Rich