Ground Source Tempering Of Incoming Fresh Air.

[creeky]

this is something I've been thinking about now that my solar shed reaches completion (with addition of a MPPT controller and 4 more batteries ).

why not use earth tempered air with an ashp in my very cold climate. the mold issues disappear. you're not introducing the air into the home, just extracting the heat.

perhaps you could even take the earth tempered air and pull it through a solar air heater and then take that air to the ashp.

excellent thread

[AC_Hacker]

Originally Posted by creeky

this is something I've been thinking about now that my solar shed reaches completion (with addition of a MPPT controller and 4 more batteries ).

why not use earth tempered air with an ashp in my very cold climate. the mold issues disappear. you're not introducing the air into the home, just extracting the heat.

perhaps you could even take the earth tempered air and pull it through a solar air heater and then take that air to the ashp.

excellent thread

This all sounds like it will work, if you're trying to find better ways to use an ASHP.

There is a very rough rule of thumb that each heat exchanger costs you 10% of your energy. so all things being equal, it's a good idea to reduce the number of exchangers.

With just a bit of hacking, you could run pipe in the ground and pump water through, and use that water directly in your heat pump. Water is a much better medium to transport heat (or cool) than air.

Air conditioners and portable heat pumps are everywhere. I got one just yesterday and the woman wanted to pay me to tale it away, I had to decline.

I got home and tested it out, and it seems that it's nothing more than a bad motor starting capacitor. So now I have a 12,000 BTU/hr heat pump that I can turn into what-ever-I-want.

You can too. If you want to go GSHP, you'll need a water to refrigerant heat exchanger. I really like Brazed Plate exchangers that I find on ebay for a reasonable amount.

Auqario (AKA:Nigel) in Spain prefers to make his own exchangers from copper tubing and plastic pipe, they work fine for him and they're keeping his house warm through a Spanish winter. He gets air conditioners and modifies the refrigerant tubing so that they extract heat from the air and then use that heat to warm water which he pumps through radiators inside his house.

-AC_Hacker

[Larry Smitherman]

Could you install precooler(like radiator) a couple of inches from heat pump and circulate warm fluid(in winter) and cool fluid ( in summer) to increase the efficiency of the heat pump? You could use ground source or well for water source. Anyone ever try this ?

[Xringer]

I've been thinking about radiator (water to air HX) a sitting in the center of the
air in-take of a mini-split.
But, since I don't have a water source for it.. It's not on my bucket list..

[Ryland]

Originally Posted by Larry Smitherman

Could you install precooler(like radiator) a couple of inches from heat pump and circulate warm fluid(in winter) and cool fluid ( in summer) to increase the efficiency of the heat pump? You could use ground source or well for water source. Anyone ever try this ?

Yes, you could, but it would be a round about way of doing things, if you want to have a heat pump take advantage of a ground loop it's best to hook it right to the ground loop instead of using air as an exchange medium, because air has low thermal mass.

[Xringer]

Originally Posted by Ryland

Yes, you could, but it would be a round about way of doing things, if you want to have a heat pump take advantage of a ground loop it's best to hook it right to the ground loop instead of using air as an exchange medium, because air has low thermal mass.

I've been thinking hacking together some kind of water-to-R410A HX.
A hack like those CPU cooler guys run..

During heating, the R410A comes back into the ODU in 1/4" line. (Bottom middle of pic)


I have some extra 1/4" line coiled up in back of my #1 ODU.
If it were to coil it up small, inside of an insulated box,
it would have little effect on cooling operations.

During cold weather, I could run warm water into the box (bottom drain)
and pre-heat the refrigerant, before it re-enters the ODU..

Just need a good source of 50-60 deg water.. (No wells dug yet).
In a dire emergency, (single digits for an extended period)
I could route city-water to the HX, just to warm up the house a bit.


Years ago, I installed a city-water powered sump pump in my basement.
http://i46.photobucket.com/albums/f147/Xringer/D004.jpg
Now, I have solar PV power to run my pumps, so it's not really needed now.
It's just a back-up for a backed-up grid..

OK, I have been lurking around here for a number of years and finally feel I have gained enough to respond to some of these dialogs.
A possible solution for your little box would be to recirculate warm water from a tub, washing machine through a filter and then to your little box to reclaim the heat. Make sure none of this warm water ever gets exposed to any public hands.
Periodically you might need to clean out your little box or provide a sedimentation tank (with an ability to clean it) prior to the little box and prior to your filter system to catch any heavy debris flowing through the process. Definitely DO NOT use any kitchen sink water. Divert the out flow of the water back to the sewer system for sure.

[Xringer]

I'm pretty sure that recovering used hot-water isn't going to provide much heating.
The amount of BTUs stored in the water (used by two people) isn't enough to make it worthwhile.

You got me thinking about water storage. We normally have a few gallons
of bottled water in stock, just in case there's a city water supply failure.
But, is that enough?
I wonder if anyone stores enough water to last a few weeks?
If city water is off-line for 4 or 5 weeks.. What will we do for water?

Anyways, if one had a large storage tank of water (or a swimming pool?),
maybe that water could be use when the ASHP needed a little boost?

~~~
I heat a small amount of hot water with a solar PV array (800w total).
Sometimes, when the hotwater is warm enough, that PV power is kinda wasted..
So, maybe if I inserted a hotwire (like an Ice-Melt wire) under the 1/4" line's
insulation, so it was in close contact with the copper tube..?.
On really cold, but sunny mornings, the PV performance is excellent.

[AC_Hacker]

Originally Posted by Xringer

I'm pretty sure that recovering used hot-water isn't going to provide much heating. The amount of BTUs stored in the water (used by two people) isn't enough to make it worthwhile.

I think that there is a rational priority to reducing energy consumption.

In other words, there are steps that you can take in the beginning that will save the largest amount of energy (infiltration reduction and insulation for example), and then the next best step, etc, etc.

So as an example, if two people lived in a house that had poor insulation, and serious infiltration problems, then it is true that the energy saved from domestic heat reclamation would be small when compared to the large volume of energy that was being wasted by the house. Also, ground source pre-heating and pre-cooling of domestic air (which is the subject of this thread) would also seem very small.

Best to pick the low-hanging fruit first and then start working with the ladder.

But it would be misleading to suggest to others who had done the major Eco-Renovating that domestic water heat recovery was a wasted effort.

Ditto ground source pre-heating and pre-cooling of air.

-AC_Hacker

[Xringer]

It isn't a wasted effort, since it can work well, for apps like pre-warming the cold water input to your shower.

But, "domestic water heat recovery" for space heating?? Maybe, if you live in one of those Zero heat loss houses..