The idea of low temperature heating and high temperature cooling (AKA: low exergy heating and cooling) has interested me for a few years now.
Today I
came across a report regarding a novel design for heat exchangers that uses fine wires. Here is a quote from the report on fine wire heat exchangers (AKA: Fiwihex):
Quote:
When a heat exchanging system like a radiator is replaced by a Fiwihex, the energy that is needed in a room for heating still remains the same and is independent of the heat exchanging system. The important advantage of the Fiwihex is not that it needs less energy to heat a room, but that it needs energy of lower value. This makes it possible to use heat that would else have been worthless.
(emphasis mine)
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Why is this important?
It is important in that it pertains to solar water and space heating.
Solar heating is regarded as low temperature heating. Conventional thinking is that when a reservoir of solar heated water becomes lower in temperature than 115F degrees, it is of little use in space heating. With attention to low temperature heating approaches, the minimum useful temperature can be significantly less than 115F degrees.
This can imply:- more days and hours that 'all-solar' heating can be used.
- a smaller heat storing reservoir can be used.
- less solar collector can be required.
It is also important to heat pumps, both ASHP and GSHP, since the higher temperature that a heat pump is called on to create (AKA: the higher the lift), the lower it's efficiency.
Another important possibility that low exergy places before us is the direct use of geothermal warmth and coolness, without the need of a heat pump for heating or air conditioning.
* * *
Information in the US about low exergy heating and cooling is not so easy to come by. There was an initiative started about 15 years ago by a group of mostly northern European countries to study this approach and to share information. The US was invited to become a member and/or to become a financial contributor to this initiative, but the US declined on both accounts.
The European consortium maintains a web site
HERE.
[*
DEAD LINK There is an interesting page on the site called
The Guidebook that may serve as an introduction. *]
NOTE: This material is dissappearing form the Internet. However, I have been able to drag a full PDF copy if the Guidebook from the dustbin of history
HERE.
There are
books on the subject, but they are very expensive. Almost no libraries in the US carry books on this subject.
Perhaps we can share information here...
Best,
-AC_Hacker