WtW Efficiency gain of lower temp. Load Tank - Page 2

NiHaoMike · 04-09-14, 10:10 PM

Draw it out and I might be able to simplify the system by having pumps be shared between different functions.

buffalobillpatrick · 04-11-14, 02:51 PM

http://ecorenovator.org/forum/attach...1&d=1397245854

http://ecorenovator.org/forum/attach...1&d=1397245854

NiHaoMike · 04-11-14, 05:27 PM

I don't see how the first drawing would work, but the second drawing looks like a reasonable starting point. I'll see what I can do.

buffalobillpatrick · 04-11-14, 05:32 PM

I modified #1 from what I found here:

Phc News - Columns: February 2013: Bristol Stickney

"Primary loop configuration. Standardize the solar/hydronic piping. A primary loop “flow center” piping configuration allows multiple heat sources to be connected to multiple heat loads and to provide heat directly, to bypass any source or any load or to allow simultaneous operation of any source or load. In past articles, I used a simple primary loop combisystem called “Combi 101” to illustrate these features on a system that includes a bank of solar heat panels, a boiler, a domestic hot water tank and warm floor space heating. - See more at: http://www.phcnews.com/oct_12/solar.php#sthash.8j0sjgv7.dpuf"

NiHaoMike · 04-11-14, 05:41 PM

That would require a lot of changes to make it work with a heat pump and still have bypass mode.

Exactly what modes of operation are you interested in?

buffalobillpatrick · 04-11-14, 10:52 PM

Please explain: "bypass mode"

Modes of operation:
1. Solar heats DHW tank if it's output is hot enough (>150*F)
2. Boiler heats DHW tank.
3. Winter, Solar heats Radiant floors directly (not via HP) if > 90*F
4. Winter, Solar heats Thermal Accumulator if > 110*F which provides heat to Radiant floors.
5. Winter, Solar provides heat input to HP Evaporator (35->90*F),
HP condenser heats Thermal Accumulator (110*F)
which provides heat to Radiant floors.
6. Winter, boiler heats thermal accumulator which provides heat to
Radiant floors.

NiHaoMike · 04-12-14, 09:04 AM

"Bypass" is #1, #3 and #4 on your list.

It seems like you can considerably simplify the design by not having the second tank. Since the main tank is like a regular water heater but with a pair of copper tubes running inside it (correct? or is it just one?), you could have DHW running in one of the tubes instead of the tank itself. Then you don't need to worry about bacteria growth since the water would be changed quite rapidly with regular use.

buffalobillpatrick · 04-12-14, 12:36 PM

Which tank are you calling "main"?

Neither the DHW tank, nor the Thermal Accumulator have internal HX.

One reason why I want at least 50 gal. of 140* DHW is that there will be a soaking tub.

NiHaoMike · 04-12-14, 01:27 PM

I don't see why you would need (or want) water that hot for a soaking tub. The main tank is the 120 gallon.

Are the tanks constructed in such a way that it would be reasonably easy to add copper tubing inside?

Does the boiler have its own tank or is it a tankless?

buffalobillpatrick · 04-12-14, 02:04 PM

"I don't see why you would need (or want) water that hot for a soaking tub. The main tank is the 120 gallon."

Because soaking tub holds 100 gallons. The Thermal Accumulator is no longer used for DHW, it now contains nasty boiler water + it is now kept at lower temp. to allow for higher Eff. when HP is heating it.

"Are the tanks constructed in such a way that it would be reasonably easy to add copper tubing inside?" Not Possible.

"Does the boiler have its own tank or is it a tankless?" Boiler = CI NG, no tank but weighs 300# & holds several gallons.

04-09-14, 10:10 PM	#11
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	Draw it out and I might be able to simplify the system by having pumps be shared between different functions. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

04-11-14, 02:51 PM	#12
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	http://ecorenovator.org/forum/attach...1&d=1397245854 http://ecorenovator.org/forum/attach...1&d=1397245854 Attached Thumbnails

04-11-14, 05:27 PM	#13
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	I don't see how the first drawing would work, but the second drawing looks like a reasonable starting point. I'll see what I can do. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

04-11-14, 05:32 PM	#14
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	I modified #1 from what I found here: Phc News - Columns: February 2013: Bristol Stickney "Primary loop configuration. Standardize the solar/hydronic piping. A primary loop “flow center” piping configuration allows multiple heat sources to be connected to multiple heat loads and to provide heat directly, to bypass any source or any load or to allow simultaneous operation of any source or load. In past articles, I used a simple primary loop combisystem called “Combi 101” to illustrate these features on a system that includes a bank of solar heat panels, a boiler, a domestic hot water tank and warm floor space heating. - See more at: http://www.phcnews.com/oct_12/solar.php#sthash.8j0sjgv7.dpuf" Last edited by buffalobillpatrick; 04-11-14 at 06:12 PM..

04-11-14, 05:41 PM	#15
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	That would require a lot of changes to make it work with a heat pump and still have bypass mode. Exactly what modes of operation are you interested in? __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

04-11-14, 10:52 PM	#16
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Please explain: "bypass mode" Modes of operation: 1. Solar heats DHW tank if it's output is hot enough (>150F) 2. Boiler heats DHW tank. 3. Winter, Solar heats Radiant floors directly (not via HP) if > 90F 4. Winter, Solar heats Thermal Accumulator if > 110F which provides heat to Radiant floors. 5. Winter, Solar provides heat input to HP Evaporator (35->90F), HP condenser heats Thermal Accumulator (110F) which provides heat to Radiant floors. 6. Winter, boiler heats thermal accumulator which provides heat to Radiant floors. Last edited by buffalobillpatrick; 04-12-14 at 12:15 AM..*

04-12-14, 09:04 AM	#17
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	"Bypass" is #1, #3 and #4 on your list. It seems like you can considerably simplify the design by not having the second tank. Since the main tank is like a regular water heater but with a pair of copper tubes running inside it (correct? or is it just one?), you could have DHW running in one of the tubes instead of the tank itself. Then you don't need to worry about bacteria growth since the water would be changed quite rapidly with regular use. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

04-12-14, 12:36 PM	#18
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Which tank are you calling "main"? Neither the DHW tank, nor the Thermal Accumulator have internal HX. One reason why I want at least 50 gal. of 140* DHW is that there will be a soaking tub. Last edited by buffalobillpatrick; 04-12-14 at 12:43 PM..

04-12-14, 01:27 PM	#19
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	I don't see why you would need (or want) water that hot for a soaking tub. The main tank is the 120 gallon. Are the tanks constructed in such a way that it would be reasonably easy to add copper tubing inside? Does the boiler have its own tank or is it a tankless? __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

04-12-14, 02:04 PM	#20
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	"I don't see why you would need (or want) water that hot for a soaking tub. The main tank is the 120 gallon." Because soaking tub holds 100 gallons. The Thermal Accumulator is no longer used for DHW, it now contains nasty boiler water + it is now kept at lower temp. to allow for higher Eff. when HP is heating it. "Are the tanks constructed in such a way that it would be reasonably easy to add copper tubing inside?" Not Possible. "Does the boiler have its own tank or is it a tankless?" Boiler = CI NG, no tank but weighs 300# & holds several gallons.