There is another reason it is not done. Cost. A solar ammonia system big enough to cool a typical house would be so expensive that if you put the 5-7% interest it would cost to finance it against the utility bill from a standard DX package you would be losing money. Ditto if you paid cash. You could make enough in interest by investing the money to more than pay your electric bill. Your investment would never pay for itself. Plus how many people like looking at a big industrial scale mess of mirrors and pipes in there backyard. OR in their neighbors back yard. Add in the possibility of having to evacuate the neighborhood if there is a leak and your insurance company would have kittens.
You are correct. Though quite safe, it's still possibility of leaking. Safety, i think, is the most common factor when someone thinks about ammonia system.
Here is article in Ashrae Journal - "Ammonia Future", it talks a lot about Ammonia as a trend in using refrigerant.
Unsafe? but... would it really be much worse than an ammonia leak confined inside of a house, as in a gas fired freezer? if I had to pick, I think I would take my chances with the outside heat pump leaking. I dunno.
just put it outside in some far corner of the yard and run glycol lines.
It will likely take up your entire yard, unless you have multiple acres. Take a look at how big a unit that can only make a few ice cubes is. There are some plans for that around the internet. Multiply by 10 then figure in the added cost of the pump, glycol etc. energy to pump the glycol etc. What are you saving? Better to put the effort into a really efficient DX or a evaporative water cooled condenser.
I am going to build a solar powered A/C system eventually
That is what I set out to do: build a solar powered absorption chiller. But in working towards that goal I realized that I could more cost effectively spend time by first reducing my need for cooling.
I have some hydronic solar collector panels installed (120 square feet) and have two more (80 square feet) waiting for my pipefitter attentions.
But before I get to that I am replacing my roof with very high SRI standing seam metal roofing - in Solar White. I chose the aluminum substrate which lasts pretty much forever and the coating reflects 83% of the sun's heat back out and away from the house. Out in the bright sun it is cool to the touch.
Plus, I replaced all the siding with styrofoam-filled vinyl over 1" foil faced foam board. And I am adding extensive insulation to the attic spaces.
At present I have six tons of A/C running here and I'd like to get to needing only two tons. At that point I think the solar heat powered absorption system can be done cost effectively.
Well; unless I count my own nearly priceless time. <g>
Originally Posted by few2many
Has there been any work on a solar powered amonia absorbtion hvac system?
I know they are used for rv refrgerators and small scale stuff. Also, I realize that for a home sized hvac, it would be pretty large. It takes a little heat from a propane flame to remove heat from the evap. This could probably be supplimented with solar heat.
Last edited by Poodle Head Mikey; 09-06-2010 at 01:28 PM.
Reason: too many b's - not enough d's
The conventional view serves to protect us from the painful job of thinking.