Subject: Re: Water to heat/cool a house

From: [email-masked] (Grant S. Robertson)
Date: Sat, 08 Feb 1997 09:32:35 GMT

J Chace <[email-masked]> wrote:
>Aitight houses use heat exchngers to take care of moisture and smell!! It 
>works.

Do you have any recommendations on these heat exchangers?

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From: [email-masked] (Stevo)
Date: Sun, 09 Feb 1997 18:32:15 GMT

Your post was most interesting.
My son just purchased a 5 acre lot in Mill Neck New York (Long Island)
It's a relatively flat parcel with plenty of open space (so when the
sun shines it will get to the structure.)  He will be building a
4-5000 sq. ft. home and is interested in utilizing geothermal , solar,
or other alternative energy source. Will this fly in our area?   We
have not yet contracted a builder, feeling that a general plan should
be worked out, then a real architectoral design made up.  Do  you know
anyone in our area?  Could you point us at a source of plans to
ponder?
Thanking you in advance
Stevo
On 31 Jan 1997 08:31:19 -0500, [email-masked] (Nick Pine) wrote:

>Al Hartkopf <[email-masked]> wrote:
>
>>I think ceiling fans in every room will do the job of circulating the air
>>around the room and result in an overall cooling of the room due to the
>>temperature of the slab. Think that will work?
>
>Conduction works well with 2" concrete walls insulated on the outside.
>Monolithic Domes have 2" of concrete with 3" of foam on the outside, and
>the temperature difference from top to bottom of a 200' diameter dome is
>said to be less than 5 F. A nice solar house: the sun shines in a window
>or insulated air heater and warms the room, and the warm air rises to the
>ceiling and heat conducts back down the walls. Perhaps these domes distribute 
>solar heat too well... They might work even better as solar houses with some
>way to control the heatflow, storing heat at a higher temperature in the mass
>above, eg the concrete roof or a 110 F ceiling pond with some foil underneath
>and a horizontal ring of form insulation replacing part of the concrete wall,
>with a few vertical water pipes running through the ring instead of plain 
>reinforcing rod.
>
>Where will the coolth come from, in your house? How much is needed? How
>much groundwater flows under the site? How deep? Perhaps you could use a
>floorslab in contact with the ground, with pipes running through it, with
>insulation around the perimeter and on top, and insulate the slab from the
>walls of the house. Foam will support 10-30 psi...
>
>>This will be built in North Carolina, west of Raleigh.
>
>Looks like a great place for a solar house. January is probably the most
>difficult month for solar heating in Raleigh, with an average of 1130 Btu/ft^2
>of sun falling on a south wall and a 24 hour average air temperature of 38.9 F
>and an average daily max temp of 48.9 F, according to NREL. The next step
>might be to calculate the heat loss of your house using ASHRAE arithmetic,
>by adding up each exterior surface area divided by its R-value. You may not
>have much wind/air leakage with concrete walls. The average yearly air temp
>in Raleigh is 59.3 F, which might be close to ground and slab temps.
>
>>The terrain is rolling hills and the altitude is a little above Raleigh. We
>>think that a hefty roof overhang, calculated to allow winter light in, is
>>in order. Still on the right track?
>
>NREL suggests 1' of south glazing height needs 0.293' of opaque surface
>above it and 0.417' of overhang above that at your 36 N latitude. 
>
>>One issue along these lines of cool slab and cool room is condensation.
>>Anybody now how to predict the temperature that "dew" will begin to form
>>on the cooled floor? Seems like it is a temperature difference that causes
>>this.
>
>And air leakage. Where else does the water vapor come from? Seems like a good
>idea to ventilate this house at night, and button it up during the day. July
>looks like the warmest month in Raleigh, with an average air temp of 78.1 F,
>88 during the day and 68.1 at night. 
>
>>...the southwest. That's the only place I ever saw those water cooled heat
>>exchangers. We lived in Yuma (hot!) and that thing really kept us coooolll.
>
>Sounds like you are talking about evaporative cooling. NREL says the average
>humidity ratio in July is W = 0.0149 lb water vapor/lb dry air, corresponding
>to a water vapor partial pressure of p/(1+0.62198/W), with p = 14.5 psia in
>Raleigh, and less at your higher altitude; 68 F air has W = 0.01478 at
>saturation, so you might see fog at night and dew on the morning grass,
>without much use for evaporative cooling (how about a roof pond?)   
>
>>I thought about doing exactly this as it would provide a platform for
>>dehumidifying the house. Thats a real concern when things start to drip
>>around here in July.
>
>I don't think evaporative cooling would help this house much, but a dark
>low-thermal-mass dessicant sunspace floor might absorb water vapor from house
>air in the early morning, and dry and bake out in the sun with the sunspace
>vented to the outdoors during the day. The sunspace floor might be lightweight
>reinforced concrete insulated below, containing expanded shale which absorbs
>13% of its weight in water. It might have a polyethylene glycol fountain
>absorbing 11 times its weight in water... How much water vapor do you need
>to absorb to keep your house at 50% RH and 75 F inside, if it leaks 1 ACH
>for 12 hours a day?
>
>Nick
>

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From: "Fred M. Gerow" <[email-masked]>
Date: 9 Feb 1997 21:51:58 GMT

If you have south facing glass and a humidity problem you have a couple of
choices.  One would be an air to air heat exchanger and another would be a
solar green house full of green growies that should if properly managed
balance the equation.  KISS

Andrew McKegney <[email-masked]> wrote in article
<[email-masked]>...
> [email-masked] (Alan Horowitz) wrote:
> 
> >In <[email-masked]> [email-masked] (Nick Pine) writes:
> 
> >   I am not visualizing this. Can you explain what is meant? Ascii art,
> >maybe?
> 
> 
> >>And air leakage. Where else does the water vapor come from? 
> 
> >     Those darn inhabitants, Nick. Wouldn't it be easier if people
didn't
> >insist on _breathing_ inside their own homes?
> 
> >I feel that water evaporation from the toilet and in the plumbing's
water
> >traps can be a source of water vapor.
> 
> Let's see...... cooking, bathing, washing floors/counters etc.,
> plants, dogs, cats, birds, fish (tanks)..........
> 
> It should be a well known fact that air tight houses have humidity
> problems (too much) because of the water vapour that is generated
> INSIDE the house.
> 
> Andy McKegney
> 
>

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From: [email-masked] (Stevo)
Date: Sun, 09 Feb 1997 18:32:15 GMT

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From: "Fred M. Gerow" <[email-masked]>
Date: 9 Feb 1997 21:51:58 GMT

didn't
water