Prestige Solo 110/Indirect Water Heater vs Navien Combo/On-Demand Water Heater

Reply

  #1  
Old 02-17-12, 06:33 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
Prestige Solo 110/Indirect Water Heater vs Navien Combo/On-Demand Water Heater

I am looking the update my heating system. I currently have an Arcoleader Boiler 2B J1/Ruth Oil Tank. I had a Home Energy Performance done. Now I have 2 estimates. 1 Company likes the Prestige Solo 110 and other Navien Combo.
Can you enlighten me on both systems? Which is a better system? Pros/cons? Also with the Prestige Solo can I use a better cost effective water heater(this is very pricey)?
 
Sponsored Links
  #2  
Old 02-17-12, 07:13 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Hello,
You need a heat loss for your house.
What type of radiation is there?

Navien's can't put out more than 50,000 btu's if you need 180 degree water, at a standard 20 degree delta T. The internal pump is only 5 gpm.


I hear good things about TT.
Naviens are much more complex.

Peter
 
  #3  
Old 02-17-12, 07:39 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
air leakage is at .69. can you simplify your answer.
 
  #4  
Old 02-18-12, 07:39 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Air leakage is not heat loss.

How did you arrive at the .69 ? Did you have an energy audit with a blower door test ?

My vote is on the TT ...
 
  #5  
Old 02-18-12, 12:05 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
yes i had a energy audit done
 
  #6  
Old 02-18-12, 05:23 PM
Z
Member
Join Date: Dec 2008
Location: United States
Posts: 158
Received 0 Votes on 0 Posts
Not true PeterNH with primary/secondary piping

You need to understand how mod cons work. When have you seen a high btu mod con system heat requirement match boiler flow?
 
  #7  
Old 02-18-12, 06:32 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Hello ZL,
I'd say that depends on the lowest temperature that is needed to heat the house.
True, a 75 degree diffrential can be run to get all the heat out at 5 gpm, but if that return temperature of 110 is too low to heat the house, it is not going to work very well.

Peter
 
  #8  
Old 02-18-12, 06:40 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Choices,
.69 sounds like the inflitration rate, which is very good.
Did they also give a heat loss in BTU's per hour?

Radiation:
Where does the heat in you house come from?
Cast iron radiators?
Baseboard with aluminum fns on copper pipe?
Hot air blowers, heated by boiler water?
Or maybe radiant heat in the floors?

Howw many swuare feet is your house?

Peter
 
  #9  
Old 02-18-12, 09:16 PM
Z
Member
Join Date: Dec 2008
Location: United States
Posts: 158
Received 0 Votes on 0 Posts
Peter, I don't believe you understand how heat thermal transfer happens in primary/secondary pipe boiler systems.
You should read siegenthalers books, especially about primary/secondary mixed stream formula calculations.

There's isn't a Gianni type heat exchanger boiler out there for instance that runs on the hydronic heat emitter principal of 20 degree DT.

One must understand the laws of thermodynamics to accept how mass transfer takes place. That with boiler operation and you can understand how heat is transferred from source to space.

In simple terms. Starting out whether it be a simple on off boiler or a modulating, what's the fire rate of both when switched on with a room temp system - answer is full fire.

What's the fire rate of a standard on/off boiler set at 180 with return water of 170? Answer none, it's off on limit, heat transfer has slowed as radiation hit saturation.

Guess what mod con is still fired at 170

That's just to start.

You see when calculating mixed stream formula, in short, using your 5 GPM example;

5 GPM boiler water at 150 degree set point primary loop with a 70 degree return water at 15 GPM secondary (150,000 btu heating load at 20DT) results in a 90 degree boiler return water temp.

150-90 = 60

60 x 500 x 60 = 150,000 btu firing rate matching heat load requirements.

If I was wrong 70% installed mod cons wouldn't be working.
 
  #10  
Old 02-19-12, 01:04 AM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Hello ZL,
Your arguments are all correct, except for 3 points.
1. I've read Siggy's newest edition a couple of times and there is nothing in there i don't understand.

2.
5 GPM boiler water at 150 degree set point primary loop with a 70 degree return water at 15 GPM secondary (150,000 btu heating load at 20DT) results in a 90 degree boiler return water temp.
We do not know what the btu load is for Choices.

Where i live on a -10 degree day 70 degree return water is not going to cut it. Not by a long shot. Not even close.
Even if i send out 190 degree water, if it comes back at 70 degrees for an average of 130 in the baseboards the rooms at ends of the zones are going to be seriously cold.

3. We don't know what type of heat emitters Choices has and their temperature requirements for full comfort. If they require 170 avg water temp to work correctly, depending on the BTU load of the house. 5 gpm 190 to 150, with that unit at 5gpm is only going to produce 50,000 btu's. Agree this?

This unit works opposite the typical mod con which flows 10-20 gpm in the boiler loop, not 5.

Yes, if Choices has high mass radiant or old, oversized, cast iron gravity conversion, ok.

If Choices has baseboard/fin tube that is not oversized and a load over 50,000 "it's not going to work very well"

Peter
 
  #11  
Old 02-19-12, 07:34 AM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
If i understand correctly, this Triangle Tube Combi
does not have the limitations of the Navien.
Check it out:
TriangleTube

IMO, i agree with NJT, go with the TT regular boiler and an indirect. Plenty of hot water.

Peter
 
  #12  
Old 02-19-12, 09:15 AM
Z
Member
Join Date: Dec 2008
Location: United States
Posts: 158
Received 0 Votes on 0 Posts
I give up based on some posts and questions on other forums you are still living in the old world of IBR sizing where 1 GPM at 20DT = 10,000 btus. That is true and many design their heat system emitters that way but that is not how you calculate heat transfer when a boiler is decoupled from system flow, via primary/secondary.

Your post indicates, again you don't understand calculating mixed stream formula for primary/secondary systems, you are misunderstanding the simple system and boiler return temps.


For instance since you reference the fine triangle tube products, the Challenger combi 125,000 btus claims a 110,000 DOE net, however their installation manual states not to exceed 6 GPM.

Now how is that? Rated for 125,000 heating but according to you it would only be a 60,000 btu boiler.

Tell the 1,000's that have installed both the Navien and Triangle tube they don't work right?

Again time to study more about boilers son.
 
  #13  
Old 02-19-12, 10:22 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
Is this discussion helping the OP ? Play nice... please don't hijack this thread, if you want to discuss (not argue, no ego) the fine points of moving heat, please start a new thread.
 
  #14  
Old 02-19-12, 10:44 AM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
NJT please don't kill me.
I would like to defend my self from intentional falsehoods.
The 6GPM figure is the MINIMUM allowed not the max.
Please see the lower left hand corner on page 2 in this link.
http://www.triangletube.com/document..._Submittal.pdf
quote:
Note: Minimum allowable
flow rate at full
input: 6 gpm [23 lpm]
CC 125
Sorry NJT
This ends it for me on this.

Peter
 
  #15  
Old 02-19-12, 02:16 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
Right now the house uses oil. I will be converting to gas. My house is heated through baseboards. My house is a bi level and 1148 sq ft on each floor.
 
  #16  
Old 02-19-12, 03:40 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
And you still have not told us what your heat loss in BTU/HR is.
 
  #17  
Old 02-19-12, 04:20 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Maybe we can figure it out backwards, with degree days and sq. feet, if we can find out how much oil Choices used the last few years.

Do you have that info Choices?

Peter
 
  #18  
Old 02-20-12, 05:25 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
when you say heat loss are you asking me what i spend in oil in a year($2,000 to $2,500)? Is this info located in the audit cause i could not find it.
 

Last edited by CHOICES; 02-20-12 at 05:51 PM.
  #19  
Old 02-20-12, 05:32 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Hello Choices,
Do you know how many gallon of oil you buy a year?

Peter
 
  #20  
Old 02-20-12, 05:53 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
just revised my previous post. $2,000 to $2,500.
 
  #21  
Old 02-21-12, 11:08 AM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
That is 600 to 700 gallons of oil per year.
 
  #22  
Old 02-21-12, 11:42 AM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Hello Choices,
What part of NJ do you live in?
Trying to find out your Degree Days and Design Temperature.
Does the energy audit say anywhere on it, how many Degree Days, are typical for your location?
Same for Design Temp., does it say anything on the audit?

Peter
 
  #23  
Old 02-21-12, 03:00 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
when you say heat loss are you asking me what i spend in oil in a year
No. A heat loss calculation is a measure of how many BTU/HR your home loses in heat to the outside world. This is used to properly size a replacement boiler for maximum energy efficiency.

If on the coldest and windiest day of the year, your home loses say 60K BTU/HR of heat, your system has to be only large enough to replace that lost heat. In this example, that would of course be a 60K BTU/HR boiler.

There's no sense installing a larger boiler than needed, it's a waste.

If your home is of 'average' construction, I would ballpark about 60-70K BTU/HR heat loss MAX. So the 110 that you are thinking of in the TT boiler may be twice as large as needed. This is why it's important to either DO or HAVE DONE a heat loss calculation, in ADDITION to the blower door test.

You can do it yourself. Slant/Fin years ago made available a program that's pretty easy to use. It takes a couple hours to do, first time. They don't offer it anymore, but it is still available here:

Contact Us - P.V. Sullivan Supply Co., Inc.

This runs on my XP machine, don't know if it will work with Vista or 7.

Peter, worst case for the majority of NJ would be about 5500 DD and 10, although northwestern Joisey may be 0 or 5.
 
  #24  
Old 02-21-12, 03:23 PM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,970
Received 11 Votes on 11 Posts
The Slant/Fin program would be good for the prospective boiler owner to run. You'll learn a lot.

Do you now have natural gas available? If not, wait and install a gas-fired boiler.

Here is a quick-and-dirty way to estimate your house's design heat loss. Wait until the coldest weather conditions (maybe too late for this year?). If the boiler runs continuously and the inside temp is maintained, then the heat loss is approximately equal to the net output of the boiler. If the boiler fires, say, 75% of the time, then the heat loss is 0.75 x boiler net output (Btu/hr). But, running the Slant/Fin program would be much better - and it's answer will be on the high side, no need to add addtional design margin in sizing a new boiler.
 
  #25  
Old 02-21-12, 04:42 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
(maybe too late for this year?)
We didn't even have a CHANCE this winter to do this! I've used less than HALF of my normal allotment of oil this year. I'm calling it "Nature's Economic Stimulus Package". I've had a lot more beer money this winter!

it's answer will be on the high side,
Absolutely. About 20% or so. Do NOT "add" anything to it!

It could take a few minutes to D/L that program file, it's about 175 Mbyte, so prepare for about a 10-15 min D/L... if you're still in the 20th century on a dial-up, D/L overnight!
 

Last edited by NJT; 02-21-12 at 07:46 PM.
  #26  
Old 02-21-12, 07:17 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
First, I would like to say thanks for everyone that is helping me out. This is an investment and I want to make the right decision. I am not knowledgeable of boilers but I can compare it to buying a car. The contractor said he would run the numbers and see if I can use the solo 65 but he thinks the solo 110 will be suitable . I will email him tonight to find out what is my heat BTU/HR. I also do have gas in house which is easy accessible and lines are already positioned for easy install.
 
  #27  
Old 02-21-12, 07:38 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
He can't just 'run the numbers'. He has to take measurements. Walls, windows, doors, room sizes, educated assumptions about the amount (or lack of) insulation, etc. This is all that is involved in doing the heat loss yourself. It really is not at all difficult. A few hours with a tape measure and entering the numbers into the program. Take a shot at it! As gilmorrie said, it's a great learning experience! It's easier than preparing a federal income tax return.

If the contractor wants to measure the baseboards in order to determine the correct size boiler, STOP! That is NOT the way to determine the correct size boiler. Nor is looking at the size of the old boiler and installing same. When fuel was cheap 2X 3X even 4X too large boilers were routinely installed. I would bet that the installed base of boilers that are way to large probably approaches 90% ! Believe it or not...

Don't make a mistake that will cost you money for the next 25 years! Take the time to do a proper heat loss calc. By the way, it's also called "Manual J". Google the terms to learn more, there's plenty of info on the net about it.
 
  #28  
Old 02-21-12, 07:42 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 3 Votes on 2 Posts
I also do have gas in house which is easy accessible and lines are already positioned for easy install.
And hopefully they will be of the correct size. Make sure of that before installation. Some older homes have undersized supply lines! This is VERY important! You do not want to starve the system for gas, the pressure needs to be maintained. Too small a pipe and the boiler (and your other appliances) will not be able to run properly.
 
  #29  
Old 02-21-12, 08:51 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Peter, worst case for the majority of NJ would be about 5500 DD and 10
OK i'll do that, with 700 gallons.
First. A few observations.
IMO 700 gallons in that mild climate, for that size house, is painfully much. The boiler is a beast.
Going from 700 gallons at what is fast becomeing 4.00+ a gallon to natural gas is going to save a bundle. No doubt a properly sized and installed TT will end up paying for itself faster that one would think.

-----------
Woking backwards iterations with the Hydraulic Design Studio.
700 gallons
3.50 a gallon = $2450.00
5 degrees design
5500 degree days
70 degrees indoor temp
70% effic.
comes out to 55,000 btu hr at design
at 60% effic.
48,000.

Oh by the way using these numbers with nat gas at 1.25(high?) a therm and 92% effic.
the cost would be $805.00
Plus hot water?
Also the above calcs would be quite a bit less if the existing boiler is making hot water.
A question we didn't ask. ?

I will say that ZL is correct in that mild climate the Navien would do the job.
But i'm all for the TT 60.
Sounds like a good fit, unless you are in a southern warm corner of NJ, then it might be oversized.


Curious to see what the SlantFin calculates.

Peter
 
  #30  
Old 02-22-12, 05:23 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
NJ Trooper
He can't just 'run the numbers'. He has to take measurements. Walls, windows, doors, room sizes, educated assumptions about the amount (or lack of) insulation, etc. This is all that is involved in doing the heat loss yourself. It really is not at all difficult. A few hours with a tape measure and entering the numbers into the program. Take a shot at it! As gilmorrie said, it's a great learning experience! It's easier than preparing a federal income tax return.
I should have some free time to do this over the weekend. I saw the auditor measuring rooms and windows.

By the way, it's also called "Manual J".
Company will be sending a contractor/boiler guy out to do a more detail survey of house. He would be able to tell me what size boiler and water heater I need. The auditor thinks I would need a Solo 110 but that is not his field of work. The auditor did say they will use Manual J. The gas pipe size will be checked.

OK i'll do that, with 700 gallons.
First. A few observations.
IMO 700 gallons in that mild climate, for that size house, is painfully much. The boiler is a beast.
Going from 700 gallons at what is fast becomeing 4.00+ a gallon to natural gas is going to save a bundle. No doubt a properly sized and installed TT will end up paying for itself faster that one would think.

-----------
Woking backwards iterations with the Hydraulic Design Studio.
700 gallons
3.50 a gallon = $2450.00
5 degrees design
5500 degree days
70 degrees indoor temp
70% effic.
comes out to 55,000 btu hr at design
at 60% effic.
48,000.

Oh by the way using these numbers with nat gas at 1.25(high?) a therm and 92% effic.
the cost would be $805.00
Plus hot water?
Also the above calcs would be quite a bit less if the existing boiler is making hot water.
A question we didn't ask. ?

I will say that ZL is correct in that mild climate the Navien would do the job.
But i'm all for the TT 60.
Sounds like a good fit, unless you are in a southern warm corner of NJ, then it might be oversized.
Peter your right on the dot. Also the current boiler is making hot water. It does not have a separate water tank. There is no warm corners in Central NJ. We have had a mild winter. If I understand you correctly and what everyone said the Solo 110 is over sized.

Also, I will ask the contractor what the electrical usage of the water tank for the solo 110 or 65 is. I need to compare it to the On-Demand Navien system.
 

Last edited by CHOICES; 02-22-12 at 05:45 PM.
  #31  
Old 02-22-12, 06:47 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Also the current boiler is making hot water. It does not have a separate water tank. There is no warm corners in Central NJ. We have had a mild winter. If I understand you correctly and what everyone said the Solo 110 is over sized
No doubt about it the 110 is too big.

The best plan, imo, would be the TT60 with and Indirect Water Heater, that heats the water from the TT60. Not an electric water heater.

Peterr
 
  #32  
Old 04-17-12, 07:22 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
Update. My Manual J number is 54 BTU. So now my last decision is between 2 contractors and cost. I will like to hear your opinion.
1 contractor (has good feedback) proposes an install of Prestige Solo 60/Smart 40, air sealing and attic insulating (thicker)
2 contractor (only saw one feedback and it was negative. feedback was related to energy audit) proposes to install Navien/on demand hot boiler, air sealing, lighting and attic insulating

Contractor #1 price quote is $3,000 more. Comparing prices from both there are 2 prices that stand out and total to about $2,000. One price seems to be a double charge and other is not truly needed.
 
  #33  
Old 04-18-12, 05:03 AM
T
Member
Join Date: Jul 2009
Location: Toronto
Posts: 1,174
Received 0 Votes on 0 Posts
Contractor 1 seems to be looking after your interests.
Air sealing and more insulation, these will help reduce your heat loss and fuel usage.
The equiptment is good also, though I might move up to a 110 for a little quicker DHW recovery. Just my 2 cents, we seem to like favour DHW performance over matching the boiler to the heat load closer up here.
 
  #34  
Old 04-18-12, 04:40 PM
P
Member
Join Date: Feb 2011
Location: US
Posts: 552
Received 0 Votes on 0 Posts
Hello Choices,
I agree with TO on #1.
Unless you are using a ton of hot water i'd go with the 60.
My oil boiler puts out about 66,000 but's hr and i never run out of hot water. Two showers can typically be taken at once.
I didn't quite follow the money numbers, but you will be saving so much money vs the old oil clunker, things will pay back the extra 3000 rather quickly, imo.

Peter
 
  #35  
Old 04-18-12, 09:09 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
Thanks everyone for all the information and help. It has made my decision making less complicated. Contractor #1 is who i will be going with. I will post contractor name and my review of them once work is finished.
 
  #36  
Old 03-06-13, 02:18 PM
C
Member
Thread Starter
Join Date: Feb 2012
Location: usa
Posts: 15
Received 0 Votes on 0 Posts
An update. I had the Navien installed. Then I had it taken away by Sandy Super Storm. I had another one installed. I can not find the right words to explain how happy I am with this system. It has brought nothing but warmth to the home and savings. I just need to figure out how to run this high tech system. Wish they had a simply app. . Thanks to all the help, advice and knowledge given.

thanks again.
 

Last edited by CHOICES; 03-06-13 at 02:44 PM.
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: