Heat Pumps and Electric Heating - Enclosing an outdoor heatpump??

I have been thinking about enclosing my external electric heatpump with a shed of some sort and opening vents to/from the crawlspace under the house.

The c-space is 30'x40' by about 3' high. It is constructed with cement block and the ground is covered with plastic so its not so bad, as such places go. The temp in the c-space is about 15 degree warmer/cooler that the outside [depending upon the season], so I think this should help with the amount of energy used.

I was thinking of constructing a plain framed enclosure with wood siding and could vent the h-pump with louvers of some sort for the exhaust and open a couple of 8x16 holes in the block wall to let bring in fresh partially conditioned air. I could also fliter the air as comes from under the house.

Well, does this make any kind of [good] sense??

thanks for your thoughts

- John Jay

i'm not sure what you're trying to accomplish. feeding your heat pump with crawlspace or basement air just puts additional work load on the unit as whatever you are running at the time it is attempting to bring that space to temp as well. besides, i'm not sure the h/p could move air in that manner and still run efficiantly. if you're chasing an alternative method of ground source thermal properties, even if it worked, it wouldn't last long. i can see the logic but the physics don't add up.
one winter out of frustration and 15 degree temps, i pointed a 30kbtu space heated at my heat pump.. now that worked !!!:eek:

JohnJay let it go! Ive got this picture in my mind and its bad! unit needs to breath, it needs about two feet all the way around it! Plus you will have to replace it some Day!

your description is kinda confusing, but i would'nt recommend enclosing the heat pump(if that is really what you have). if you still have the book that tells you of the clearances of where to set the heatpump, it never says anything about being enclosed. just let us know what you have (names,brand,etc.) maybe we will be able to give you a better answer. but as it stands now, i have not, or ever seen an enclosed heatpump ,

barry

I have seen descriptions of heatpumps used in large spaces such as a conference center and seen pictures described as being heatpumps located in a tunnelway under a school building..

The issue of enclosure size is not important as I can build any size needed. I have been considering buidling a mechanical type room addition to hold a freezer on this side of the house as well, perhaps it could be one structure.

I imagine that some issues would be the airflow characteristics and the amount of good 3500 cu ft of pre-conditioned air would ultimately provide...

thanks for your thoughts

- john jay

The temp in your crawlspace is that low because there is little airflow.

A few minutes of running, and the fan on the condensor will have completely exchanged the air under the home with outside air. The same air it would be drawing without the enclosure.

If anything, you will see higher energy usage, as you no longer have the 3' of still air under the home.

I like the way you think John. Although this idea is not practical and will not work, you are at least thinking in the right terms. I have seen a heat pump in a building and it worked very good. But unless you have a barn full of 100 cows giving off heat or some other source of free heat in the building, you are out of luck. Think about a geothermal heat pump. The earth has an endless supply of energy stored that will never be tapped as much as it should be.

:) What you are thinking of is a good idea. With a good designed ground tube you can assure that the air temperture drops only just below freezing or stays above freezing http://www.passivehouse.com. If the floor between your basement and the house is well insulated you can use this space for the same purpose.

I have put the high side of a HP in a cave and it worked very well. With a crawl space here . We seal them up with insulation on the walls and a good poly on the ground. Then put outlets and returrn in the duct down there. This lets the crawl space work as a large heat sink. Any home we have did this way the fuel cost has been less this way than if its open down there and the floor has insulation in it.
The fan that is in the highside couldnt pull the air through for what you want to try.

ED:wall:

Hey Ad, thanks for the link. Now youve got me thinking of an even more efficient system for my home. I wont stop untill my heating system pays me.

The one with the most payback that I know of . Is the vertical ground coil. Put in for a DX geothermal heatpump. This way the ground temp goes right into the freon lines in the ground. Not ground temp to water then water temp to the freon .:thinker:

ED;)