Portable Heat Pumps

Started by alcowboy, November 12, 2008, 04:37:49 PM

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alcowboy

http://shop.ebay.com/items/?_nkw=portable+heat+pump&_sacat=0&_fromfsb=&_trksid=m270.l1313&_odkw=portable+heat+pump&_osacat=0

Hey gang! Have anyone of you heard or had any experience with these? I am hoping that once I get my house built this would work instead of purchasing a much more expensive traditional heat pump.  For a 20x30 1-1/2 story with 12' exterior walls, would either the 9,000 or 12,000 btu suffice if these are at all usuable instead of the traditional?

MountainDon

First depending on how cool/cold it gets outside and how warm you need the interior I wonder if 9K or 12K would be enough capacity?

Here is a link to an imperfect calculator. It's imperfect because it doesn't take insulation, windows and other variables into account.

http://www.gas-space-heater.com/heater-sizing.html
Just because something has been done and has not failed, doesn't mean it is good design.


alcowboy

For some of the heating I plan on installing either a wood stove or a fireplace insert (not yet decided) which should cut down on the load for heating. Even at the price I find on these heat pumps I could afford 2 if it became necessary. I am sure it would be cheaper to run these versus the heat pumps outside. Any ideas on this thought?

MountainDon

#3
Quote from: alcowboy on November 12, 2008, 10:17:02 PM
I am sure it would be cheaper to run these versus the heat pumps outside. Any ideas on this thought?

I wonder why you think that?  I believe that if these were used in a larger home with many rooms, it might be more efficient overall to heat or cool just one or two rooms than the whole house. Example, my 1600 sq ft single story home; probably cheaper to cool or heat just the 2 rooms used most. I'm not sure how that would apply to a 600 sq ft (+ loft) home though, because it seems to me I'd be more likely to be using all or most of the space most often.

??? ??? ??? ???  anyone else?
Just because something has been done and has not failed, doesn't mean it is good design.

MountainDon

The initial cost on even a couple of portables should be a lot less than a fixed system I would think.
Just because something has been done and has not failed, doesn't mean it is good design.


John_C

I'm very skeptical that those would do more than heat/cool one room.

You really didn't give enough information to work with.  I looked up where Chambers Co. Al is, and you are quite a bit south of me, here in the N GA mtns., so I would guess you wouldn't have too much of a heating load and that summer cooling would be more of a problem.

There are a lot of other factors.  How much insulation will you have in the walls and ceiling.  The least expensive energy efficient thing you can do to reduce summer cooling load is to have a white or reflective roof.  Any 1-1/2 story house has some issues with warm air rising, resulting in the loft being considerably warmer than the main floor.  If you arrange some way to get air circulating from high up back down to the main floor the house will be more comfortable. 

If I were building in that climate I would try to get as much of my heating needs via solar.  Our coldest weather is usually sunny, so it shouldn't be a problem.  Almost any decent wood burning stove would heat the entire house.  The hot - humid summers are more difficult.  I get by (barely) without AC here in the mountains but it would probably be a necessity in your location.  I'd guess you would need one of those units for the loft and another one or two downstairs.  I don't know about the cost but the noise would send me looking for another solution.

Two of the larger units would be 2 tons of AC.  That would be considered very minimal for a house of that size in your location.

MountainDon

I forgot about the noise.  d* d*   That is one thing I really don't like about window mounted A/C.  I imagine those portables would be much the same.
Just because something has been done and has not failed, doesn't mean it is good design.

glenn kangiser

I bought one - fairly large portable.  I consider it garbage -- It froze up all the time and heat is nearly non-existant when cold out.  We bought a large portable A/C for the bedroom , with a 1500 watt heat element in it and it was way better than the heat pump.
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

alcowboy

Well I guess the noise factor would be non-existant for me as I sleep with a fan running anyway. I guess what I am considering most here is cost factor. I am living check to check and my credit is shot so I am having to consider the lowest cost alternative in building and in maintaining my house; therefore, looking at all solutions. I know I have not had the time to fully research the alternatives yet as I have lots of small projects going at the same time and my head is constantly spinning with ideas and ways to do something at a lower cost. I wish that solar power was much cheaper as that is the perfect solution. You can add to it as your load increases. I am considering some wind power too so that is a consideration in addition to solar. I also saw on a segment this morning that solar water heaters are a constructive, energy efficient way to cost savings.

You see, I would like to be able to build a home locally that does not cost the hundred's of thousands that everyone here locally seems to have been wanting and let people know that they can live comfortably on a much smaller budget to maintain a home.


John_C

I feel your pain.  I've had to close my long standing business and postpone plans to build a new house.

From an energy efficiency standpoint approach each side separately.  You should be able to get most to all of your heating from solar.  You can add a wood burning stove. and/or an inexpensive propane heater that would placate the building code, bank, insurance company.  The heating side can be complementary. Most of the time you wouldn't need the latter two. A small wood stove would be more than adequate for normal cold, cloudy weather in your climate.  The propane would only be needed in the event of some unusually cold weather.

Cooling is much more difficult.  You can design a house that vents itself well through chimney effect. The problem in central Alabama is that even at night the outside air isn't all that cool.  Once you go to AC it's an all the way proposition.  You can't open a few windows to embrace the breeze and still run AC. 

You can insulate very well. You can choose to use AC in one or two rooms only at night. My house in the FL Keys was cooled by two window units that had a total capacity of 1-1/3 tons. The local utility company recommended 6 tons...  their calculations at that time were all wrong.  I had 36 feet of sliding glass doors on the N side covered by a 10' overhang.  We could leave those doors open in all but the worst weather and get a nice breeze.  The utility folks said we would burn up with all that exposed glass. Their energy calculations didn't factor in orientation.  Of course that house was designed with no consideration for heating side energy efficiency.  I had a small wood burning stove that I never lit in 7 years.  A few times we plugged in a 1500w space heater.  Heating really wasn't an issue.

The hard part is to combine the two.  I'm of two minds whether thermal mass is a good thing in a climate like yours.  It's great in the winter but something of a liability in the summer.  It just doesn't cool off enough at night and the thermal mass retains the daytime heat long into the night.  The old cracker houses had very high ceilings with double hung windows that would be left open at the top to allow warm air to escape.  The were low thermal mass and built off the ground on stilts to encourage the movement of air beneath the floor.  Some had operable vents in the floor to allow the cooler air beneath the house to enter and create natural circulation.

I would suggest you visit the    Marjorie Kinnan Rawlings  house in Cross Creek FL.  http://www.floridastateparks.org/marjoriekinnanrawlings/

It's a great education in how folks got by pre-AC.  A lot of what those folks did could be adapted to modern construction at minimal cost.


alcowboy

John I am sorry to hear of your loss of the business.  :(

Write Obama, he may be able to help - NOT! Or even the bail out package may could be changed to send billions your way.

Really, I am saddened to hear of your loss.

dogneck

I am building a 14x24 addition to be used as a workshop.  Due to dust and lacquer smells, I don't want to connect to the main house system.   I am going to use a PTAC system.   These are basically what you find in most hotels.   They have models that are fairly efficient (heat pumps).   I'm looking at the carrier brand.

alcowboy

what brand do they carry? LOL!

From what I can tell the PTAC is not much more expensive than the ones I have looked at and YES those things will either freeze you out or burn you up in a hotel room!!!

dogneck

#13
This is where, I'm going to order- 

http://www.lodgemart.com   

52mqu-12-3 model.   Carrier brand.



ED: linked url - MD