My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

On Jan 4, 5:53*pm, JIMMIE wrote:
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

Water to air heat exchanger. Or, Plate heat exchanger.
Example.
http://www.heatexchangersonline.com/airtowater.htm
http://www.brazetek.com/
Don't forget it will reduce the airflow.

JIMMIE wrote:
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

Google "water to air heat exchanger for furnace".

I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

On Jan 4, 1:49*pm, bob haller wrote:
I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

Another factor is a forced air system frequently already
has a heat exchanger in it, the AC evaporator. Adding
another obstacle for the air to go through will create
more resistance for the blower. It might create enough
so that it burns it out the blower motor. Or the added
resistance reduces the cooling performance in summer,
etc. Overall, doesn't sound like a great idea to me.

On Jan 4, 2:24*pm, "
wrote:
On Jan 4, 1:49*pm, bob haller wrote:

I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

Another factor is a forced air system frequently already
has a heat exchanger in it, the AC evaporator. *Adding
another obstacle for the air to go through will create
more resistance for the blower. *It might create enough
so that it burns it out the blower motor. *Or the added
resistance reduces the cooling performance in summer,
etc. *Overall, doesn't sound like a great idea to me.

ROFL...

Not just cutting it into the duct work and adding it to what
is already there, but modifying the trunk where the AC coil
is located with some dampers and adding a place for the
hot water heat exchanger would do just fine without burning
out any fan motors as it blows the air past the AC coil just
fine without burning out now...

It sounds to me like the OP's idea will have a high initial
cost and would be quite a while before any sort of ROI is
realized...

~~ Evan

On Jan 4, 2:48*pm, Evan wrote:
On Jan 4, 2:24*pm, "
wrote:

On Jan 4, 1:49*pm, bob haller wrote:

I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

Another factor is a forced air system frequently already
has a heat exchanger in it, the AC evaporator. *Adding
another obstacle for the air to go through will create
more resistance for the blower. *It might create enough
so that it burns it out the blower motor. *Or the added
resistance reduces the cooling performance in summer,
etc. *Overall, doesn't sound like a great idea to me.

ROFL...

Not just cutting it into the duct work and adding it to what
is already there, but modifying the trunk where the AC coil
is located with some dampers and adding a place for the
hot water heat exchanger would do just fine without burning
out any fan motors as it blows the air past the AC coil just
fine without burning out now...

Clueless as usual. Re-routing the air through another
path via dampers, etc, creates significant additonal drag
as well. And I would not be surprised to find that the
addional resistance is MORE than just putting another
coil in the existing loop. Any of those add to the load
on the blower.

Want to tell us again how it's illegal to vent nitrogen into
the atmosphere from an AC system and how it must
be recovered as you claimed? Or how a homeowner with reasonable
skills is gonna die if they dare to cut and re-glue a simple PVC pipe?

Clueless, totally clueless.





It sounds to me like the OP's idea will have a high initial
cost and would be quite a while before any sort of ROI is
realized...

~~ Evan

Gee, you really think so?

You need the word "hydrionic" which will help out. Beyond that, I'm not a
lot of help.

I think using solar to help heat the house is a great idea. Best wishes,
hope you can make it work for you.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"JIMMIE" wrote in message
...
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

On 1/4/2012 12:53 PM, JIMMIE wrote:
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.


We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

On Jan 4, 4:01*pm, RBM wrote:
On 1/4/2012 12:53 PM, JIMMIE wrote:

My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

I did the reverse of that using cold groundwater to help cooling in
the summer. I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. I don't see why the OP couldn't try an auto radiator
and save a lot of $$$ over buying something else.

On Jan 4, 5:01*pm, RBM wrote:
On 1/4/2012 12:53 PM, JIMMIE wrote:

My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

My son is an engineer who has a lot of "farm boy horse sense" and
pretty good about figuring out anything. He has already considered
that adding another coil may restrict the air flow too much. Not
knowing any info on the heat exchanger it wasnt an idea he had
completely tossed. This system wouldnt be the only source of heat just
an augmentation to to decrease his power bill hopefully. I think he
would be happy if it just heats his "great room". It is beginning to
sound like this is going to be a separate system that just heats the
main part of the house.

Jimmie

hr(bob) wrote:
On Jan 4, 4:01 pm, RBM wrote:
On 1/4/2012 12:53 PM, JIMMIE wrote:

My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for
hot water. He wants to add some coils to his forced air HVAC system
so he can use the solar heated water to heat his home. He was
expecting there to be a coil he could place in his HVAC system but
cant find what he is looking for or knows what to ask/google for.
Any help would be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler
loop where the go into the air handler, and set up some solenoid
valves, so whenever the thermostat called for heat, an aquastat on
the solar system would open it's solenoids as long as the water
temperature was hot enough. It would also have to turn on a
circulating pump for the solar loop. When the temperature isn't hot
enough, the aquastat would close a circuit, opening the solenoids
from the boiler loop and it's pump, and fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

I did the reverse of that using cold groundwater to help cooling in
the summer. I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. I don't see why the OP couldn't try an auto radiator
and save a lot of $$$ over buying something else.

Just don't use household water pressure in an auto radiator.

On Jan 4, 5:31*pm, "hr(bob) "
wrote:
On Jan 4, 4:01*pm, RBM wrote:





On 1/4/2012 12:53 PM, JIMMIE wrote:

My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

I did the reverse of that using cold groundwater to help cooling in
the summer. *I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. *I don't see why the OP couldn't try an auto radiator
and save a lot of $$$ over buying something else.- Hide quoted text -

- Show quoted text -

Auto heater cores is something that has been considered..

Jimmie

The OP may be well served, to set up a separate hot water heat system. I
knew some folks who used a car radiator and a fan indoors. Outdoors they had
a wood stove with pipe loop inside the stove. Hot and return pipes under
ground, and circulating pump. One of a kind, the people and the heater.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"hr(bob) " wrote in message
...

I did the reverse of that using cold groundwater to help cooling in
the summer. I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. I don't see why the OP couldn't try an auto radiator
and save a lot of $$$ over buying something else.

Too small to do much good. Try auto radiator.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"JIMMIE" wrote in message
...

Auto heater cores is something that has been considered..

Jimmie

On Wed, 4 Jan 2012 11:24:25 -0800 (PST), "
wrote:

On Jan 4, 1:49Â*pm, bob haller wrote:
I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

Another factor is a forced air system frequently already
has a heat exchanger in it, the AC evaporator. Adding
another obstacle for the air to go through will create
more resistance for the blower. It might create enough
so that it burns it out the blower motor. Or the added
resistance reduces the cooling performance in summer,
etc. Overall, doesn't sound like a great idea to me.
More resistance won't burn out the blower motor unless it totally
restricts the air-low to the point the motor heat is not removed..

Rducing airflow just makes the blower turn EASIER, not harder.
Try blocking a vacuum hose and listen to the blower SPEED UP.

On 1/4/2012 9:53 AM, JIMMIE wrote:
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

a large automotive heater core may fit the bill.

--
Steve Barker
remove the "not" from my address to email

On Wed, 04 Jan 2012 17:01:32 -0500, RBM wrote:

On 1/4/2012 12:53 PM, JIMMIE wrote:
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.


We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

Personally, I'd go at it a little differently. Since this solar assist
is not the PRIMARY heat source, I'd install the solar hydronic loop in
the RETURN air to the furnace - and to avoid excessive restriction I
would put it in PARALLEL with the existing return air duct . Properly
designed, the heat exchanger could have very little more restriction
than the open return, and a system of dampers could restrict the
airflow on either side to extract the maximum heat from the solar
loop.

Because the delta T is higher on the return side than on the heated
side, you would get more heat ( in absolute BTUs) out of the solar
assist than if it was being used on the outlet side.

On Wed, 4 Jan 2012 14:31:17 -0800 (PST), "hr(bob) "
wrote:

On Jan 4, 4:01Â*pm, RBM wrote:
On 1/4/2012 12:53 PM, JIMMIE wrote:

My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

I did the reverse of that using cold groundwater to help cooling in
the summer. I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. I don't see why the OP couldn't try an auto radiator
and save a lot of $$$ over buying something else.
Even a couple of heater cores.

On 1/4/2012 8:06 PM, wrote:
On Wed, 4 Jan 2012 11:24:25 -0800 (PST), "
wrote:

On Jan 4, 1:49 pm, bob wrote:
I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

Another factor is a forced air system frequently already
has a heat exchanger in it, the AC evaporator. Adding
another obstacle for the air to go through will create
more resistance for the blower. It might create enough
so that it burns it out the blower motor. Or the added
resistance reduces the cooling performance in summer,
etc. Overall, doesn't sound like a great idea to me.
More resistance won't burn out the blower motor unless it totally
restricts the air-low to the point the motor heat is not removed..

Rducing airflow just makes the blower turn EASIER, not harder.
Try blocking a vacuum hose and listen to the blower SPEED UP.

I check the current draw of blower motors in air handlers. If the amps
are low, you know the motor isn't working very hard because it's not
moving any air. ^_^

TDD

On 1/4/2012 4:31 PM, hr(bob) wrote:
On Jan 4, 4:01 pm, wrote:
On 1/4/2012 12:53 PM, JIMMIE wrote:

My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

I did the reverse of that using cold groundwater to help cooling in
the summer. I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. I don't see why the OP couldn't try an auto radiator
and save a lot of $$$ over buying something else.

Um, what's a "cookling system"? Does it have something to do with
managing very young cooks? o_O

TDD

Naah, that's a space age automatic cooking system that only makes cold food.
Think Star Trek, for example.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"The Daring Dufas" wrote in message
...
On 1/4/2012 4:31 PM, hr(bob) wrote:


the summer. I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. I don't see why the OP couldn't try an auto radiator

Um, what's a "cookling system"? Does it have something to do with
managing very young cooks? o_O

TDD

On 1/4/2012 9:28 PM, Stormin Mormon wrote:
Naah, that's a space age automatic cooking system that only makes cold food.
Think Star Trek, for example.


I thought "cookling" and "youngling" were similar in some respects? ^_^

TDD

On Wed, 4 Jan 2012 19:01:59 -0500, "Stormin Mormon"
wrote:

Too small to do much good. Try auto radiator.

Christopher A. Young
Learn more about Jesus
www.lds.org
.

"JIMMIE" wrote in message
...

Auto heater cores is something that has been considered..

Jimmie

How many BTUs do you get out of an automotive heater? SOME heater
cores would be too small, but many are about 100 square inches and 2
1/2 inches thick. The advantage is they are DESIGNED for roughly 3/4"
hose, and the flow rates involved, while radiators are designed for
roughly 2 inch hoses and the much higher flow rates. 2 heater cores
from something like an old impala or Chevy Suburban would likely be
more than adequate.

On Jan 4, 6:01*pm, "Stormin Mormon"
wrote:
Too small to do much good. Try auto radiator.

Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"JIMMIE" wrote in message

...

Auto heater cores is something that has been considered..

Jimmie

I said radiator, not heater core. Heater way too small

On Jan 4, 9:59*pm, wrote:
On Wed, 4 Jan 2012 19:01:59 -0500, "Stormin Mormon"

wrote:
Too small to do much good. Try auto radiator.

Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"JIMMIE" wrote in message
....

Auto heater cores is something that has been considered..

Jimmie

How many BTUs do you get out of an automotive heater? *SOME heater
cores would be too small, but many are about 100 square inches and 2
1/2 inches thick. The advantage is they are DESIGNED for roughly 3/4"
hose, and the flow rates involved, while radiators are designed for
roughly 2 inch hoses and the much higher flow rates. 2 heater cores
from something like an old impala or Chevy Suburban would likely be
more than adequate.

Trust me, you want a large surface area so you don't restrict the air
flow too much, heater cores are simply too small, unless you used
maybe at least 4 of them

On Jan 4, 10:59*pm, wrote:
On Wed, 4 Jan 2012 19:01:59 -0500, "Stormin Mormon"

wrote:
Too small to do much good. Try auto radiator.

Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"JIMMIE" wrote in message
....

Auto heater cores is something that has been considered..

Jimmie

How many BTUs do you get out of an automotive heater? *SOME heater
cores would be too small, but many are about 100 square inches and 2
1/2 inches thick. The advantage is they are DESIGNED for roughly 3/4"
hose, and the flow rates involved, while radiators are designed for
roughly 2 inch hoses and the much higher flow rates. 2 heater cores
from something like an old impala or Chevy Suburban would likely be
more than adequate.

The unit has a slot for an electrotatic airfilter that is not being
used, my son plans on test various designs by building them so the
will slide in place of the filter. He may well be able to find a
radiator that would fit. He was talking about taking a look at the
heater core out of a school bus one day this week to see how it may
fit.

Jimmie

On Jan 4, 6:49*pm, bob haller wrote:
I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

You are right.

On Jan 4, 7:24*pm, "
wrote:
On Jan 4, 1:49*pm, bob haller wrote:

I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

Another factor is a forced air system frequently already
has a heat exchanger in it, the AC evaporator. *Adding
another obstacle for the air to go through will create
more resistance for the blower. *It might create enough
so that it burns it out the blower motor. *Or the added
resistance reduces the cooling performance in summer,
etc. *Overall, doesn't sound like a great idea to me.

Reduced airflow reduces load on the fan motor.

On Jan 4, 10:31*pm, JIMMIE wrote:
On Jan 4, 5:01*pm, RBM wrote:





On 1/4/2012 12:53 PM, JIMMIE wrote:

My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

My son is an engineer who has a lot of "farm boy horse sense" and
pretty good about figuring out anything. He has already considered
that adding another coil may restrict the air flow too much. Not
knowing *any info on the heat exchanger it wasnt an idea he had
completely tossed. This system wouldnt be the only source of heat just
an augmentation to *to decrease his power bill hopefully. I think he
would be happy if it just heats his "great room". It is beginning to
sound like this is going to be a separate system that just heats the
main part of the house.

Jimmie- Hide quoted text -

- Show quoted text -

There will not be as much heat available as you think. A tankful of
hot water is not that much heat. You nedd to do some sums before
starting this work. It is probably uneconomic.

On Jan 5, 12:01*am, "Stormin Mormon"
wrote:
The OP may be well served, to set up a separate hot water heat system. I
knew some folks who used a car radiator and a fan indoors. Outdoors they had
a wood stove with pipe loop inside the stove. Hot and return pipes under
ground, and circulating pump. One of a kind, the people and the heater.

Christopher A. Young
Learn more about Jesus
*www.lds.org
.

"hr(bob) " wrote in message

...

I did the reverse of that using cold groundwater to help cooling in
the summer. *I used an old automobile radiator placed in the air
stream in addition to an A-coil that was part of a regular central
cookling system. *I don't see why the OP couldn't try an auto radiator
and save a lot of $$$ over buying something else.

Tch. Why not just have the stove indoors? What a stupid idea.

This system wouldnt be the only source of heat just
an augmentation to *to decrease his power bill hopefully. I think he
would be happy if it just heats his "great room". It is beginning to
sound like this is going to be a separate system that just heats the
main part of the house.

Jimmie

thats the way to go, seperate system to just heat one room.

the question is how much will that room need heat when the solar
collector has excess heat to supply?

You're all thinking deep inside the box.

You're fixated on "I have hot water, and I want hot air coming from my
airhandler, so I have to put hot water in my airhandler, how do I do
it?"

There's a better way.

You're making that hot air with a heat pump, which is extracting heat
from the surroundings. Put your hot water around your heat pump, and
it becomes much more efficient.

Then you have another benefit. Your ductwork and airhandler are
designed (if done correctly) for volume of air at a given
temperature. So the controls will still work and you won't short
cycle.

Then in the summer, when you're dumping excess heat from your heat
pump to cool the house, you dump some of that heat into your hot water
system. You get efficiency improvement year round.

On Jan 4, 9:06*pm, wrote:
On Wed, 4 Jan 2012 11:24:25 -0800 (PST), "

wrote:
On Jan 4, 1:49*pm, bob haller wrote:
I wonder how often the solar heater will provide needed heat to the
home.

if may not be cost effective

Another factor is a forced air system frequently already
has a heat exchanger in it, the AC evaporator. *Adding
another obstacle for the air to go through will create
more resistance for the blower. *It might create enough
so that it burns it out the blower motor. *Or the added
resistance reduces the cooling performance in summer,
etc. *Overall, doesn't sound like a great idea to me.

* More resistance won't burn out the blower motor unless it totally
restricts the air-low to the point the motor heat is not removed..

Rducing airflow just makes the blower turn EASIER, not harder.
Try blocking a vacuum hose and listen to the blower SPEED UP.

You do realize there is a difference between a modern
ECM blower motor on a furnace and a vacuum cleaner
that is cavitating, don't you? An ECM motor tries to
maintain constant airflow. Put more resistance on it
and it uses more power to push the air harder. They
are typically spec'd for a maximum pressure. If you
put more resistance in a duct system, be it another
heat exchanger or a clogged filter, you INCREASE
the power used and at some point you decrease
the life of the motor.

Also, furnaces have a min airflow reqt to keep the
heat exchanger within it's correct operating range.
Put more resistance in the duct work and you
could exceed that limit as well.

On Jan 5, 8:36*am, TimR wrote:
You're all thinking deep inside the box.

You're fixated on "I have hot water, and I want hot air coming from my
airhandler, so I have to put hot water in my airhandler, how do I do
it?"

There's a better way.

You're making that hot air with a heat pump, which is extracting heat
from the surroundings.

Did he say that it's a heat pump system? I didn't
see that.


*Put your hot water around your heat pump, and
it becomes much more efficient.

How exactly would he do that? Sounds even less
practical.




Then you have another benefit. *Your ductwork and airhandler are
designed (if done correctly) for volume of air at a given
temperature. *So the controls will still work and you won't short
cycle.

I seriously doubt the excess heat from a system sized to
for a water heater is going to create short cycles. I'd
first get a handle on how many additional BTUs it will
provide and I would not be surprised to find that it's just
not worth it.




Then in the summer, when you're dumping excess heat from your heat
pump to cool the house, you dump some of that heat into your hot water
system. *You get efficiency improvement year round.

And how do you get just the right amount of water
around the heat pump versus the air that it's made
to work with? The approach of adding a heat exchanger
in the cold air return is at least straightforward.

hr(bob) wrote:
On Jan 4, 6:01 pm, "Stormin Mormon"
wrote:
Too small to do much good. Try auto radiator.

Christopher A. Young
Learn more about Jesus
www.lds.org
.

"JIMMIE" wrote in message

...

Auto heater cores is something that has been considered..

Jimmie

I said radiator, not heater core. Heater way too small

Either will likely have problems with household water pressure. And make sure
they don't use lead in the soldering, or you may contaminate the water you cycle
through them. If isolated solar heater water is used directly, no problem with
that.

On Jan 5, 8:36*am, TimR wrote:
You're all thinking deep inside the box.

You're fixated on "I have hot water, and I want hot air coming from my
airhandler, so I have to put hot water in my airhandler, how do I do
it?"

There's a better way.

You're making that hot air with a heat pump, which is extracting heat
from the surroundings. *Put your hot water around your heat pump, and
it becomes much more efficient.

Then you have another benefit. *Your ductwork and airhandler are
designed (if done correctly) for volume of air at a given
temperature. *So the controls will still work and you won't short
cycle.

Then in the summer, when you're dumping excess heat from your heat
pump to cool the house, you dump some of that heat into your hot water
system. *You get efficiency improvement year round.

Yes he has considered that and knows there are commercial systems that
do exactly what you describe. He doesnt need any more hot water than
he already has nor does he want to go to he expense of having a
system installed. Being an engineer he wants something he can DIY and
he thinks he has figured it out.

Jimmie

On Jan 4, 9:15*pm, wrote:
On Wed, 04 Jan 2012 17:01:32 -0500, RBM wrote:
On 1/4/2012 12:53 PM, JIMMIE wrote:
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

Personally, I'd go at it a little differently. Since this solar assist
is not the PRIMARY heat source, I'd install the solar hydronic loop in
the RETURN air to the furnace

I think the OP is already planning on putting it
on the return side. He said he had a filter unit
that was not being used and he could put the
heat exchanger there. On the return side is
the only place that makes sense to me.



- and to avoid excessive restriction I
would put it in PARALLEL with the existing return air duct . Properly
designed, the heat exchanger could have very little more restriction
than the open return, and a system of dampers could restrict the
airflow on either side to extract the maximum heat from the solar
loop.

You'd always get maximum heat extraction with
the most airflow through the heat exchanger, so
why the need for a system of dampers to vary
the flow?





Because the delta T is higher on the return side than on the heated
side, you would get more heat ( in absolute BTUs) out of the solar
assist than if it was being used on the outlet side.- Hide quoted text -


Agree, which is why I don't think it makes any sense to
put it anywhere else. But first thing I'd do is figure out
how many BTUs of heat are really available on a typical
day. And he could only expect to recover some portion of those,
clearly nowhere near 100%. Having some
numbers he'd have an idea if it would be worth it.

On Jan 5, 9:23*am, "
wrote:
On Jan 5, 8:36*am, TimR wrote:

You're all thinking deep inside the box.

You're fixated on "I have hot water, and I want hot air coming from my
airhandler, so I have to put hot water in my airhandler, how do I do
it?"

There's a better way.

You're making that hot air with a heat pump, which is extracting heat
from the surroundings.

Did he say that it's a heat pump system? *I didn't
see that.

*Put your hot water around your heat pump, and
it becomes much more efficient.

How exactly would he do that? *Sounds even less
practical.



Then you have another benefit. *Your ductwork and airhandler are
designed (if done correctly) for volume of air at a given
temperature. *So the controls will still work and you won't short
cycle.

I seriously doubt the excess heat from a system sized to
for a water heater is going to create short cycles. *I'd
first get a handle on how many additional BTUs it will
provide and I would not be surprised to find that it's just
not worth it.



Then in the summer, when you're dumping excess heat from your heat
pump to cool the house, you dump some of that heat into your hot water
system. *You get efficiency improvement year round.

And how do you get just the right amount of water
around the heat pump versus the air that it's made
to work with? * The approach of adding a heat exchanger
in the cold air return is at least straightforward.

This morning about 6AM I got a call from him.Thanks son Im working
evenings this week. He decided to apply the hot water to a second
system, He is going to put the radiator , in whatever form it takes,
in the fireplace. The fireplace is in the den located in the center of
the house and the HVAC unit has an air return there. He thinks he can
have a working if not pretty system installed in a day after getting
the radiator.

Jimmie

On Jan 5, 12:43*pm, harry wrote:
On Jan 5, 4:43*pm, "
wrote:



On Jan 4, 9:15*pm, wrote:

On Wed, 04 Jan 2012 17:01:32 -0500, RBM wrote:
On 1/4/2012 12:53 PM, JIMMIE wrote:
My son has a home that he added a solar water heater to a few years
ago. Works great , too great. The unit far exceeds his demand for hot
water. He wants to add some coils to his forced air HVAC system so he
can use the solar heated water to heat his home. He was expecting
there to be a coil he could place in his HVAC system but cant find
what he is looking for or knows what to ask/google for. Any help would
be greatly appreciated.

We call that a "Hydro-Air" system. The hot water coils are inside the
air handler along with the cooling coils. I think he could make his
solar system assist the boiler, but I don't think I'd rube the air
handler to do it. Possibly if he T'd the solar loop into the boiler loop
where the go into the air handler, and set up some solenoid valves, so
whenever the thermostat called for heat, an aquastat on the solar system
would open it's solenoids as long as the water temperature was hot
enough. It would also have to turn on a circulating pump for the solar
loop. When the temperature isn't hot enough, the aquastat would close a
circuit, opening the solenoids from the boiler loop and it's pump, and
fire the boiler.
The problem with doing something like this, is that the only guy who
will know how to service it, is the one who built it. If anything
malfunctions, he could be without heat for a while

Personally, I'd go at it a little differently. Since this solar assist
is not the PRIMARY heat source, I'd install the solar hydronic loop in
the RETURN air to the furnace

I think the OP is already planning on putting it
on the return side. *He said he had a filter unit
that was not being used and he could put the
heat exchanger there. *On the return side is
the only place that makes sense to me.

- and to avoid excessive restriction I

would put it in PARALLEL with the existing return air duct . Properly
designed, the heat exchanger could have very little more restriction
than the open return, and a system of dampers could restrict the
airflow on either side to extract the maximum heat from the solar
loop.

You'd always get maximum heat extraction with
the most airflow through the heat exchanger, so
why the need for a system of dampers to vary
the flow?

That is not correct.
The factors are Time, Turbulence and Temperature difference (between
the media)
All need to be maximised to get maximum heat transfer in any given
heat exchanger..

The media need to be in the heat exchanger as long as possible.

Are you trying to tell us you can get more heat out
of the same radiator system
with less air flowing through it instead of more? How do
you maximize the temperature difference if not by
using the maximum available air flow? Hmmm?? Air barely moving
results in the air being hotter in the heat exchanger and
less energy transfer. Air quickly moving results in
the air being cooler and more energy transferred.
Do they put part of the air through a furnace heat
exchanger, or ALL of it? Do they put part of the air
through an HVAC evaporator or all of it?

Turbulence does increase the transfer. You think you're
gonna get more turbuluence with reduced airflow?
Ever hear of a Reynolds number?



The media flow needs to be as turbulent as possible, (ie non laminar)

He isn't designing the heat exchanger. It's a simple
radiator. You want to make it into PHD thesis?


The temperature difference between the heating and cooling media needs
to be as high a practical, ie a counterflow system if applicable.- Hide quoted text -

- Show quoted text -

Uhhuh. And one way to get it as high as possible is for the max
airflow of the furnace to be going through the radiator. Anything
less than that for the same design and he gets less heat
transferred.