Solar thermal and heat pump

Heating, insulation, ventilation, VMC, cooling ... short thermal comfort. Insulation, wood energy, heat pumps but also electricity, gas or oil, VMC ... Help in choosing and implementation, problem solving, optimization, tips and tricks ...
zazu
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Registration: 12/12/06, 01:05
Location: Yvelines, 78

what's the weather here?




by zazu » 13/12/06, 01:38

what is this region where it would be -15 without sun for 15 days :?:
ah yes at the poles or in Lapland it's normal and even + early warm :!:
otherwise i don't know :|
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zazu
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Registration: 12/12/06, 01:05
Location: Yvelines, 78




by zazu » 13/12/06, 03:09

concerning the storage of solar energy in the basement, I remember reading the case of a college built on a rocky massif, equipped with a battery of solar collectors and vertical probes drilled in the rock.

in summer the collectors heated the rock mass, and in winter heat pumps worked on these probes with the addition of solar collectors.
after 2 years of operation the measurements showed a positive balance: the average t ° of the massif increased. obviously it is collective and difficult to apply for an individual living at the foot of a cliff!

personally I have considered another solution for coupling a heat pump and solar panels : Idea:
the idea is to have a water reserve (for me 2 tanks of 2m2 stored frost-free) that the solar panels will heat by submerged coils.
then the cap comes to pump this water which I hope to maintain between 5 and 20 ° c.
preferably I will run my PAC at night with a 1000 liter buffer tank.
and in the morning the temperature of my tanks will be low, so my sensors will start producing the first glow, just enough to heat water to 10-12 ° c.
the big problem with the sensors is that they don't pick up much when the weather is overcast and that they are asked to heat to 40-50 ° c.
but there if they heat my solar circuit to 15-20 ° c all day, I still collect calories to heat my tanks.
and in the off-season when I - need heat and solar production is more important, I derive my panels directly on my central heating.
I have a small house to heat: 80 m2 on 1 floor with good insulation and a veranda.
I have planned 10 m2 of tube collectors from bysun, a PAC of 7 kw single-phase used, the tanks and the buffer tank are also used.
I hope to have finalized my installation for winter 2007-2008.

I am convinced that this idea can be applied more widely.
ex: someone who has a well insulated indoor pool.
some panels for warming up, the cap plugged in!

another example: a rainwater recovery system, diverted from its use, buried (earlier than stripping its entire French garden for buried collectors) with a coil to heat the water as for my tanks. and of course the heat pump which pumps this water for its operation.
a rainwater recovery tank, this is around 10 m3, therefore + greater inertia for a larger floor area.
obviously provide the sensors and the heat pump accordingly.
remains a big unknown: can this system be autonomous for heating a house :?:
Personally, I am convinced that yes if it is well dimensioned and that the insulation and neat. otherwise we have always our good fireplace which will still be able to relieve my "nuclear installation" (I quote my brother).
friendships to all :P
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Other
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by Other » 13/12/06, 04:49

Hello
remains a big unknown: can this system be autonomous for heating a house
Personally, I am convinced that yes if it is well dimensioned and that the insulation and neat. otherwise we have always our good fireplace which will still be able to relieve my "nuclear installation" (I quote my brother).
friendships to all


the water in the earth is during the year from 10,5c to 12c, I use this water to heat my house with heat pump
just to give you an idea of ​​how much water is needed

or 780 liters per hour and I take between 3,8 to 4,1c this water
In very cold weather -20 it works on average 15 minutes per hour (this gives you a notion of the volume of the liquid necessary to heat a house)

If you want total annual figures of pumped water and total annual operation of the heat pump, I have a water meter and a horametre everything is measured! except that I use the PAC for air conditioning the figures are global ...

Another thing to store water at 30c or 40c, requires chlorine or other product to neutralize it, it becomes algae and bacteria it becomes a problem for filtration and pumping,
I had a heated swimming pool and once the water is too hot it requires a lot of product to stabilize its PH, I think that storing in rock masses is better suited but hard to keep for a long period ..

Andre
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zazu
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Registration: 12/12/06, 01:05
Location: Yvelines, 78




by zazu » 14/12/06, 02:23

thank you for this info André,
personally I do not think heated this capacity beyond 20 ° C.
firstly because the heat pump is likely to go into safety and then if I have such good sunshine to heat more, I prefer to send it directly to the heating circuit.
Regarding exotic blooms it seems to me that the presence of copper coils will limit the phenomenon, if not a little more chlorine.

to assess the storage capacity of 4000 liters, I took a delta T of 5 to 20 ° or 15 ° kx 1.15wx 4000. or 69kw
the heat pump itself adds around 20 kw to extract the 69 stored, or 90 kw, I think it is 4 days in the cold period.
on this side, I believe I have sufficient inertia.
afterwards, my heating possibilities will depend mainly on what my sensors can provide, knowing that the more I regulate at a low temperature the more I will have efficiency on the sensors.

PS: my goal is not to store heat in summer for winter.
it's just to pair a heat pump with sensors knowing that I have no source, not enough ground, and that I am allergic to aerothermal energy.
the idea is to have solar heating, with a performance boosted by the heat pump during the peak period.
best regards to you and to you in particular, André.
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Capt_Maloche
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by Capt_Maloche » 14/12/06, 13:30

HAN HAN ! unity problems!

zazu wrote:to assess the storage capacity of 4000 liters, I took a delta T of 5 to 20 ° or 15 ° kx 1.15wx 4000. or 69kw
the heat pump itself adds around 20 kw to extract the 69 stored, or 90 kw, I think it is 4 days in the cold period.
on this side, I believe I have sufficient inertia.


15K ok; the specific heat of water is 4.18 KJ / Kg.K; 4000 l approx 4000 Kg ok

1KW = 1Kj / s

Or the amount of energy (no power) needed to raise the temperature of 4000l of water from 5 to 20 ° C = 4000x4.18x (20-5) = 250 800 KJ, in a perfectly insulated receptacle.

I did not read the beginning of the post, but for the example, if you want to pass this Qty of water from 5 to 20 ° C in 12h00 you will need a power of 250 800 / 12x3600 = 5.8KW

Conversely, by "pumping" 5.8KW for 12h00, your 4000l will go from 20 to 5 ° C.

Pascal
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"Consumption is similar to a search consolation, a way to fill a growing existential void. With, the key, a lot of frustration and a little guilt, increasing the environmental awareness." (Gérard Mermet)
OUCH, OUILLE, OUCH, AAHH! ^ _ ^
zazu
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posts: 17
Registration: 12/12/06, 01:05
Location: Yvelines, 78




by zazu » 14/12/06, 18:49

yes, as you say, Capt_Maloche, there's a bp but there I think it's a deaf dialogue.
I must have been very tired because instead of kw / h for the energy I put kw for a power.
the goal is to calculate the storage capacity (energy) of 4000 liters with 15 ° k.
so in clear: 15 ° kx 1.15w / hx 4000 liters = 69 kw / h

for all my calculations, I keep a simple value:
1.15 kw / h, to heat 1 ° c, 1m2 of water
since all the powers of PAC are in kw,
nettles calories, kilojoules and kj / s with factors 3600 to fall on his feet.
for example the cap of andré pump 780 liters with 4 ° k
therefore 1.15 kw / hx 4 ° kx 0,78 m2 = 3,588 kw / h (energy)
therefore a heat pump of 3,6 kw (very small model)
André, wouldn't it be the smallest Weissmann which is 5,5 kw (memory) in calo power.
excuse, Capt_Maloche, it's less academic, but it goes faster, I just have to think of putting the / h when it is necessary.
friendships to all


ZAZU
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Other
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by Other » 14/12/06, 19:57

Hello,

André, wouldn't it be the smallest Weissmann which is 5,5 kw (memory) in calo power


I do not know how to convert with your values, but it is not a small unit in general for a house it is one (2 tonnes) in refrigerationist language I do not know the meaning?
My unit is a 5 ton.
5 HP compressor motor
0,75 HP fan
1 HP water pump
capacity 65000 BTU
Consumption 30 amperes under 220 volts single phase

It is an old unit that I rebuilt completely with a new compressor and modified to heat domestic water in air conditioning, it is a little known brand MAMOUTHE ..

In your case why you take the water at the start at 5 c the water which stays a few days in a buried tank is at 10c
obviously if you isolate the tank and you pump the heat it will eventually go down to 4 c
The performance of the heat pump is better if you work with hotter water normally when the water table drops to 8c it becomes limited to operate the heat pump, you must increase the flow of water without which hear glitter ice pass in the exchanger, after 3 c it goes quickly and it is risky.
In reality what I do is as if I had 2 large tanks buried and I pump in one which is your 11c and I pour into the other with an output at 7c, except that I use the phreatic tablecloth, and I use the earth as a radiator.

Andre
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zazu
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Registration: 12/12/06, 01:05
Location: Yvelines, 78




by zazu » 15/12/06, 01:18

Hi friends,
hello the headache to do conversions with values ​​that I don't practice :x

André,
1 BTU is a unit of energy which is worth 0,293 w / h
and 65000 BTU = 19 kw / h
to be more precise we must say that you have a power of 65000 BTU.h (and not BTU / h which means nothing) or 19 kw.

1 HP it is in French the Horse-Steamer which is worth 736 w
so you have a total power of
6,75 HP x0,736 = 5 Kw electrical power

for tons I seemed to read that 12000BTU = 1 ton (that corresponds roughly)

65000 BTU.h is this your calorific or refrigerating power
it seems to me that the powerful. calo is the power. fridge + power. electrical - losses
but even if it's the power. calo, I find that with 14 kw of power. fridge (19-5kw) you do not cool much:
780 liters / h cooled by 4 ° k is 3,588 kw of fridge power :!:
are you sure about your numbers.
wouldn't the 780 liters be for 1/4 hour?
here we fall back on 14kw of power

could you also detail your operating cycle of your installation

some details about my project:
my tanks will not be buried, I will install them in a corner of the veranda also under construction.
I count a little on the softness of it to warm them but especially on my solar instal.
but my intention is not to take the water at 5 ° c to cool it again (I don't drink pastis).
I think of putting a safety which will block the PAC if the water which it pumps passes below 6-7 °.
the 5 ° c I was talking about is the minimum temperature of the water returned to the tanks in the lower part that the coils, also at the bottom of the tanks, will heat up.
the heat pump will pump in the upper part of the tank A and will discharge in the lower part of the tank B.
a pipe will connect the top of B and the bottom of A to rebalance the level.
so I don't immediately pump the water back up.

friendships to all and see you soon,

ZAZU
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by Other » 15/12/06, 03:20

Hello,
I was wrong in the hour calculation
Measurements are 4,2 imperial gallons per minute (18 liters)
The pump when it was new it pumped 8 gallons per minute The strainer would need a good cleaning!
So 18 liters per minute in heating I cool the water by 4 c more or less it varies depending on the duration of pressure pressure freon
The compressor draws between 22 and 25 amperes at 220 volts.
the hot air coming out of the vents from 30C to 35 C
I could improve it a little, at the beginning I had put more freon
and the motor amperage was 28 amperes, the yield was better, an exchange of 5,5 c, but at the end of winter
the water temperature drops since I return cold in the ground and when the snow cover melts, the cold descends in the ground (it is in April that the water is at its lowest 8c, therefore problem of water flow, the return water must not go down to zero!
For 65000 btu this is what is written on the heat pump in the cold cycle in heating I cannot read.
1 hp = 746 watts
For BTUs there is a calorie conversion.
it just indicates a unit of heating or air conditioning power, in practice the regulation of the system makes that there are several variable pressure of the freon temperature of the exchangers which influences the efficiency, but on average it plays in the 3
Water pumps and ventilation should not be counted to study the performance of the compressors.
The only way I used to calculate the yield is the volume of water passed through the exchanger as well as the temperature differential, in reality the calories pumped over the water.

Andre
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zazu
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by zazu » 15/12/06, 21:37

Hi everybody,
André, I realize that the English are stronger than us: even their horse-power is more powerful than our horsepower:
power and energy table

as you see in the link 1 ch is not = at 1 hp, 10 w of diff.
again, it's simple, but then when we look for BTUs, in the section energy and not power, we find 8
but hey we always shoot around 1055 joules.
Obviously BTU.h it does not exist, but using an energy value to quantify a power, it is boiled-up by professionals. for that, i was just telling you
to be more precise we must say that

Finally, do not take too much head with these theoretical details.
because in addition to that I told you that I said something stupid again:
we have to talk about kwh (and not kw / h) for an energy value so I should have said that it takes BTU / h for a power and not BTU.h (obviously neither BTU / h nor BTU.h exist).

on the other hand your new figures leave me still perplexed:
22-25 A in consumption is more reasonable for a 3,73 kw compressor (5 hp x0,746).
but for the flows you said first 780 l / h at 4 ° k it was only 3,588 kw or if you prefer 12250 BTU
now you say 18 l / min or 1080 l / h
therefore 1080 x 1,15kw / hx 4 = 5 kw / h or 17000 BTU
we are still far from the 65000 BTUs displayed
in fact, the compressor you installed will not be less powerful than the original one.
do you know your electricity consumption. in kw / h?
friendships to all

ZAZU
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