Lochinvar KBN or WHN

Heat_n_CT

Found a contractor, yes manual j was done. He's pushing KBN, but I keep reading go with the WHN for the Firetube design. I know in the end it's my money and he'll do what I want, but why do I want Firetube so bad. Thanks.

kcopp

then have that installed...or look for someone else.

Rich_49

Then WHN it should be . Period .

Zman

The KBN has a Giavonni(sp) heat exchanger. These were originally introduced in the munchkin boiler and were incorporated in many other boilers since then. They have lower thermal mass, require bigger circulators and more maintenance.
The WHN has a firetube heat exchanger introduced by triangle tube boilers. They have higher mass, require very small circulators and are very low maintenance.
This is not even a close decision. Anyone insisting on the KBN is not well informed.

Heat_n_CT

Thanks everybody. Got it now, I understand better now.

Heat_n_CT

Another contractor scheduled next week.

Heat_n_CT

Can someone give this a once over for me. Right now I have. Weil Mclain CG circa 1998, it's a 70k with a 58k DOE for a 1720 sq ft house also circa 1998. Two zones, upstairs and main floor, just about equally split at about 48' of baseboard per zone. Of the five potential quotes two took room/window/copper fin measurements...of the two man-j's only one has gotten back to me and is recommending the 79K Greenstar wall hung with a 40 gallon indirect. The other guys that didn't do any measuring are also recommending 79-85k boilers and 40 gallon indirects, well one that barely spent 10 mins here recommended the Greenstar Combi 151k.

I'm not too well versed in this stuff, but I used Slant/Fins app and I input my measurements and coefficients to my best. From what I've read from a lot of old posts is that I'd almost need to be missing a window to require an 85k boiler. I come up with 32k required and that's with no accountability for the basement besides 10" insulation 5/8 plywood below finished floor. For reference my basement never drops below mid 50's. With 32K, even if I'm 50% wrong it's only 48K? I've questioned the size everybody is recommending and the say we need to compensate for the indirect...which I read a lot is just poor practice.

Would anyone agree that 32K sounds about right for a 15yr old 1700 sq ft house at Bradley Field in CT. I've had the energy audit done and it's been said it's close to an energy star home, and was almost recommended that a fresh air unit be installed because it's so tight...ok, I know it was a $75 audit.

Guess what I'm saying is I'm 5 contractors in with #6 coming next week...could they all be wrong? I have a hard time asking if they might be wrong if I'm not 100% myself.

Rich_49

18.8 BTUs per foot sounds perfectly reasonable for a well insulated and sealed home , even in Minnesota . To answer your question , yes all the contractors could be wrong . Maybe they sized the boiler for the larger hot water load to to keep up and get back to the business of heating the home more rapidly , that would not be a bad thing . of course I have no idea about your hot water usage but it does not sound unreasonable .
In dealing with a house such as yours though taking for granted that the loads are right I would probably opt for a smaller unit with a high end around 50K like a Cadet , MC or other . A house a stight as you say yours is can stand quite a bit of time before there is a noticeable drop in indoor temp .

Ironman

Your at almost 19 btu's per sq. ft. That sounds just a little light but not unreasonable for a house built in the last twenty years. Your radiation is sized for a 48k btu heat loss. If you only need 32k btu's, that's a good thing: your supply water temp can be lowered accordingly which will save energy.

My choice would be the WHN055 for your house either way. If you have a larger than average domestic load for your house, then up-size the indirect, not the boiler. I don't know what it is with heating contractors that they won't trust load calcs and always want to up-size boilers and furnaces. It's a terrible practice that shows a lack of engineering ability. You only need the full btu output at design temp (5*). At 35*, you need half of it. And most all load calcs have about a 15% fudge factor built in.

A standard 40 gal. gas water heater usually only has a32k btu burner and does just fine for the average household. If you use a WHN055 with a 40gal. indirect, you'll have 18k more btu's. Unless you have a hot tub to fill every night or a George Jetson shower, you won't need anything larger.

Heat_n_CT

Neglected to mention water usage here, but it's myself and the wife, typical 2.5gpm shower, run a bath every 3-4 years, no hot tub. 2.5 baths, but in 15 years have never run two showers at the same time. Always coordinate the dishwasher with going to bed. Couple guys mention resale in case a big family moves in...I've told them not to worry about the next family.

Ironman

Your on track. Go with the WHN55.

Rich_49

What are the loads and lengths of BB in each room ? Do you have this information and can you post it ?

Ironman

Just to give you a reference point: I have a large family. A wife, six daughters and a son. Three of them are now out of the house, but I still have three daughters and my son here, plus my wife who fills the tub each night to soak in.

I have a 50gal. gas water heater that we use in the summer and shoulder seasons when I'm not heating with my wood boiler and we never have an issue with running out so long as a little common sense is used. Even when they were all still at home, there seldom was a problem. My washer still goes 8-10 hours a day.

SWEI

Even a CDN040 would work here, and you can't argue with the price.

Heat_n_CT

Rich said:

What are the loads and lengths of BB in each room ? Do you have this information and can you post it ?

1st floor:
DR 2700 &12'
LR 2700 & 12'
FR 5400 & 15'
KT 5800 & 9'
Hall 1400 & 0'

KT & FR could almost be combined, both spaces wide open to each other.

2nd floor:
B1 2800 & 12'
B2 2800 & 12'
MBd 3850 & 16'
MBth 2900 & 8'

Heat_n_CT

Heat_n_CT said:

Rich said:

What are the loads and lengths of BB in each room ? Do you have this information and can you post it ?

1st floor:
DR 2700 &12'
LR 2700 & 12'
FR 5400 & 15'
KT 5800 & 9'
Hall 1400 & 0'

KT & FR could almost be combined, both spaces wide open to each other.

2nd floor:
B1 2800 & 12'
B2 2800 & 12'
MBd 3850 & 16'
MBth 2900 & 8'

and upstairs hall 1100 & 0'

Rich_49

Please tell us how this is zoned . What jumps out at me is the fact that all these rooms with the exception of kitchen , Family room and Master bath can be done with less than 250 BTU per foot of baseboard . I am guessing that hallway is right in the middle and has no exposed walls ? Tell us a bit more , I think this is not that difficult to make perform better with lower temps than I am positive your contractor is thinking of .

Heat_n_CT

1st floor zone 1 and 2nd floor zone 2. Yes the hallways are in the center of the house and one full bath with no exterior walls. Set for 65 there is no feeling of cold. It's a colonial with the same footprint for each floor. 4 of the rooms are 10x12 with 2 3x5 windows in each room. FR and Ma Bed are 17x13, FR has the 7x6 patio door and one 3x5 window while the master has two 3x5 windows. Kitchen is 12x18 with 32 sq ft of windows and a door going to a cold garage. MaBath is same size as kitchen with one small 22x30 window.

The HW heater is a 40 gallon State 40K BTU tank that has been more than enough for us. Basement is perimeter joist insulated, ceiling insulated, and door to exterior insulated and weatherstripped. Windows are single hung weather stripped, doors are metal insulated weather stripped, walls are 2 x 6, attic is 12" white poly fill blown in. FR has a patio door that is going to be replaced in the near future, its kind of cold to be near. Front of the house faces east, and majority of life happens in the rear/west side of the house so it enjoys afternoon winter sun, but loathes summer afternoon sun.

The WM currently running hasn't been serviced and the Field Control power venter has been running faithfully for 15yrs. Power vent is my main goal for a new system...I absolutely hate that thing. I'm guilty of boiler neglect, but as a kid I never recall my dad servicing his...I'll drop that mentality with the new one.

One guy under consideration said he's planning on running 130*.

Anything else needed to add?

Rich_49

What outdoor temp did you use for your design and would you perform one more using 40* as your outdoor design temp .
This will help us more accurately give you a reset ratio for your installer . 130* will leave you quite short in the kitchen and family room and quite possibly the master bath . If your baseboard is Slant Fin or equal you will need much higher than 130* to deliver the required BTUs and that is assuming that the kitchen is the first piece of heast in the series .

Heat_n_CT

I used 5*. When I use 40* I get 14.4K

Rich_49

Need room by room loads .

Heat_n_CT

Sorry...

1st floor:
DR 1250 &12'
LR 1250 & 12'
FR 2500 & 15'
KT 2400 & 9'
Hall 675 & 0'


2nd floor:
B1 1300 & 12'
B2 1300 & 12'
MBd 1765 & 16'
MBth 1330 & 8'
Hall 525 & 0'

Rich_49

If at all possible I would suggest that the Kitchen baseboard be changed to a piece of Smiths Heating Edge Baseboard and be fed and returned with a 3/4" tee then allow the rest of the first floor baseboards to function as they are . Insure 1.5 gpm through the series loop . The upstairs is probably much more of an issue and will require SWT from boiler of 160* @ design and 120* at 40* , same for the first floor stuff . Heating edge baseboard in the kitchen with parallel feeds will allow a reasonably low SWT through that piece while allowing the remaining existing stuff to heat at the typical ratings .

Heat_n_CT

Great suggestion, I will pass it on to the contractor - if I find one. My kitchen is right above the boiler. Hopefully he can see other locations where this can be easily adapted. Thanks.

Heat_n_CT

I've made a few calls to the quoting contractors asking for their argument on stuffing the WHN085 boiler in my house. They all say to supply the indirect tank properly. I know I'd rather oversize the tank than oversize the boiler...feel like I'm banging head against the wall. Any tips for arguing this point? I'm running out of local contractors.

Rich_49

Don't even oversize the tank . Tell them you want to store 140* DHW in the tank and mix down to 115* . This effectively increases the storage capacity and will allow the smaller boiler to be more than sufficient

Zman

This one is largely misunderstood.
You might try explaining that a typical electric heater puts out 4500 watts x 3.415 = 15,246 BTU
A typical gas unit is around 30,000 BTU output.
How many Btu's do they think you need?
The charts that come with the indirects are maximums not minimums. As long as the indirect is large enough for the boiler (almost all are) you will get the boilers capacity as a DHW output. In the case of the WHN 85 that is around 75,000 BTU. in priority mode.

Carl

Heat_n_CT

My stand alone nat gas State 40 gallon is 40K BTU and has a first hour of 70 gallons. According to the Squire manual with a boiler heating capacity of 52.5K (WHN055) the 40 gallon tank yields a first hour of 106 gallons @140°. 36 gallons and probably 20° hotter.

Am I comprehending this right?

Heat_n_CT

Today's contractor says I need 40 BTU per sq ft of home (1700 sq ft) and I am undersized based on my current boiler's 56K BTU. He wants me to get the Bosch 131 Combi - he actually said bigger is better.

Gordy

Scratch him off the list.

Ironman

Heat_n_CT said:

My stand alone nat gas State 40 gallon is 40K BTU and has a first hour of 70 gallons. According to the Squire manual with a boiler heating capacity of 52.5K (WHN055) the 40 gallon tank yields a first hour of 106 gallons @140°. 36 gallons and probably 20° hotter.

Am I comprehending this right?

Looks right to me.

Ironman

Heat_n_CT said:

Today's contractor says I need 40 BTU per sq ft of home (1700 sq ft) and I am undersized based on my current boiler's 56K BTU. He wants me to get the Bosch 131 Combi - he actually said bigger is better.

We do a lot of old farm houses that are 100+ years old that are getting remodeled; some aren't, they're just getting a new boiler. Even the loosest ones have never calculated at 40 btu's per sq. ft.

What a clueless idiot. He needs to get a hydronic education or find a way to make an honest living.

Heat_n_CT

Does anybody have any recommendations in northern CT? At this point I'm six quotes into this and hearing the same song. I'm already realizing I have to give up on having this done by year's end, I hope CT has the same $750 rebate for 2015.

Heat_n_CT

After talking with the wife we decided to take this up in the spring. Too hectic time of year with the holidays and too much to ask for contractors to squeeze this in. Hope my power vent will get me through one more season. I'll contact Charles to see if he'll come down. Thanks everyone.

Ironman

I think that it's prudent on your part to wait until you get a competent contractor. Hope you can get Charlie to do it. He'll be worth waiting for.

Heat_n_CT

I agree, everyone seems to bypass the fact I want efficiency, not just a replacement. I started this hunt in early Nov and seemed like I had plenty of time before the end of the year. I'm so glad I took the time to learn a bit, and grateful for the time everyone here took to teach.

Enjoy the holidays folks...be back in Feb or March to start again.

Heat_n_CT

Hello, me again.
I’ve gone over my inputs again and see one mistake - I have my kitchen baseboard wrong, I typed 9’, but I see now it should be 14’. Not sure how 9’ got in there. I did have the windows measured right so I can’t blame the tape measure. Also I’m contemplating adding heat to my basement with the intention of finishing it for an extra family room. If I do this I realize it’ll probably change the boiler required so I want to be sure it’s what I want to do before I get things rolling. If I decide to do it, but say a year from now is there any problem with piping a zone and just capping it for a later date?
-
In preparation I've been pouring thru as many webpages as I can read as well as digesting the user/service manuals for the WHN units.

Can someone explain what three individual outdoor resets mean? i.e.: SH1, SH2, SH3, OD low1, OD low2, OD low3…etc. Will there be three OD stats placed around my home or does this mean it’ll control up to three different zones in the house? I think I understand adjusting the curve and all, but I still can’t wrap my head around the 1, 2, and 3.

I see in the manual that default Outdoor low is 25°, which I understand to mean when its 25° the water produced in the boiler will be at its hottest, which is controlled by the Set point for Outdoor low…default of 180°. So when its 40° out the boiler water may run at ~150°? Do I understand so far?

So when I read about “shifting the reset curve” that means if change the default to a new Outdoor low of say 5° it would mean that 180° water would happen at the 5° mark? So on a 40° day the boiler water may run at ~135°?

One other thing, is it best to treat indirect tank DHW as a separate zone or separate load? Will the answer to this depend on household usage? Is separate load the same as set as Priority?

icesailor

In my minority opinion and experience. there is a huge difference between ACCA Manual J heating calculations, and H-22 IBR/AHRI heat calculations.

Manual J is a cooling program that has heat added as an afterthought.

H-22 IBR/AHRI is a heating only program. Different goals, different outcomes.

If you want to heat, use a heating program. If both contractors are using a Manual J Program's, they will make the same mistakes.

I don't consider the money I spent on Manual J based heating programs. They taught me the difference when I never got the same results in my heating only calculations.

And I go back to the late 1990's with an old buggy DOS program that I had to figure out work around's but would never run under Windows. No matter what kind of a DOS program I set up under Windows.

The biggest difference: Under H-22, the Sun doesn't shine at night. Under Manual J, the Sun shines during the day.

Heat_n_CT

On which side do you see the difference? Man J oversizes more or less than the IBR/AHRI.

RJMCTAFO

I am located in CT also but not in your area. You may want to look into this also.....

http://www.energizect.com/residents/programs/energizect-heating-loan-program

Paperwork would need to be done by March 31 but at 0% and no fees even if you have the $$ it would let you finance it instead of cracking into the savings account.

The boiler if installed properly will differentiate between the heating call and the domestic water call. It will ramp up to satisfy the water demand and then go back to the programmed curve for heating.

I do mostly oil in my area but typically have found most systems we have replaced with reset are working great with a max temp of 160 on a 0 design day. Some with cast iron rads are running 150.

icesailor

Heat_n_CT said:

On which side do you see the difference? Man J oversizes more or less than the IBR/AHRI.

Point taken. I've done IBR/AHRI for at least 20 years. The only changes were in improved heat loss factors. Manual J programs that U ised figured both heat and cooling with the same Factors they used for cooling. Maybe they changed. I don't know. I didn't keep up with all the Manual J programs I bought. Manual J dealt with Heat Gain for cooling with heating as a added bonus. IBR/AHRI offered only heating.

Whether heating or cooling. Both use a differential between two baseline temperatures and the Delta T Temperature. If you take either one and apply it to the other, the results are amazing. Truly amazing. In my experience.

I'm teachable. I don't know everything. I just see how so many are designing to the edge of the circle. I always worried about falling off. I never did. I saw some that fell off. It wasn't pretty. If it happens to you, you better be prepared to back up what you did with your knowledge and understand how you are right, and someone else did something they weren't supposed to do.