Comfort vs. Dollars Expended: Where to stop?

Mark Adams

My usual mantra is that to get 90% of the benefit you need to spend 50% of the maximum dollars. So for my new build, this means putting in a simple hydronic system. Single stage gas boiler, simple OD reset like Tekmar 260, BB all around, boiler pump and DHW pump, or maybe just a single pump. Kinda like the Tekmar dwg A260-2 or A260-3. At work we always try to design to the KISS method and the above is certainly that.

Now the question: Just how much extra comfort is gained, and maybe fuel saved, by going top of the line? All pumped zones, full reset, mixing control for a couple of zones of radiant stapled up floor heat to go along with a few zones of BB heat. Having never experienced this type of system, I have no basis on which to make a comparison or decision!

My in-laws 1960's ranch has a two zone, one pump, single fire boiler system and it is dandy. It's way better than any single speed FHA system I've ever encountered.

My new place will be a 2200 SF ranch in western NY, well built, well insulated, good windows, etc. The heat loss is nailed down, boiler selected, indirect DHW selected. Just need to decide on complexity vs. comfort vs. $$$.

Comments?

Thanks,
Mark

Unknown

One possibility, Tekmar 363 w/Digital thermostats. Get your boiler control/reset, DHW control, radiant mixing control w/one extra pump, intelligent zone cycling.

I don't think you'd find the cost *that* much higher than the setup you are considering, and you'd have a very powerful system that covers all the major features that will benefit you and boiler. Not quite "top of the line", but probably best value. If it's a couple of small radiant zones, use PEX-AL-PEX to help safegaurd against expansion noise (otherwise I would suggest going "top of the line" with indoor feedback and RTUs, but that does get pricey fast).

If you were zoning by pump, you'd then be looking at something like $150-$200/zone, and you just need to look at the heat loads, see what you can do with balancing/emitter sizing to balance loads, and decide on your zoning.

Just some thoughts!

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.

THe biggest improvement in comfort is full-range reset, i.e. 70-180F, not 140-180F (the latter is inadequate even with BB). This requires either condensing boiler or mixing valve.

In-floor radiant is good too but much more expensive.

hydronicsmike

Where to stop, you ask? -tN4-

Not any more money than what you are doing right now with a 260 and a Relay Box. Check out tN4.

Not only does is provide Outdoor Reset with Indoor Feedback and Communication between the different devices, it also is very cost effective. tN4 is the answer to your question. Check it out at an Event near you and visit www.tekmarcontrols.com for more info.

Hope this is what you are looking for.


Mike

Mark Adams

Rob,

Looked at the 363 and it does what I need, as do other Tekmar's like the 370. I guess that I've got four basic options for hydronic indluding:

Non-Cond Boiler/263/two or three zones of BB.

Non-Cond bioler/363/same BB plus a mixed zone of rad for the baths and kitchen.

Condensing boiler for either of the two above.

Interestingly, I ran a spreadsheet to figure out just how much I might save by going with the condensing boiler. In summary, using 7%/yr fuel increases, having the extra for the condensing boiler in my mortgage at 6%, and experiencing an efficiency increase from 83-89% AFUE, I'd save enough to pay for 1/2 of a new replacement boiler in 20 years.

All this is making my head hurt, and badly enough that I might just get the dang dual level, var. sp. FHA furnace and put in electric radiant for the bathroom floors.

Later,

Mark

Mark Adams

One consideration is full BB and a condensing boiler with OD reset. Four heating months per year would be done a much lower than 180 supply. But the extra cost of the boiler would likely kill the fuel savings. See my previous reply.

Later,

Mark

Mark Adams

Bummer. The Tekmar event blew through Buffalo a week ago. As for the same $$ as 260 and accessories, are you sure? This thing looks like commercial gear that goes for $500-600 per control point.

TNX,

Mark

Unknown

I wouldn't bother with a condensing boiler with Baseboard. You'd only be condensing a small portion of the time.

I can't comment on Mike's tn4 controls since we have not learned about them yet... can't wait though... but for Tekmar's old controls the money spent on a boiler reset control should pay for itself easily. If you're adding radiant then the 363 does what you need. If not, skip it. Only you can determine what radiant comfort is worth to you!

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Chuckles_3

Ae you looking for comfort or savings? In two posts you've said two different things.

It is NEVER cost effective to replace a working boiler with another one, whether condensing or not. But you may want to get a condensing boiler to do full-range reset (=comfort, not savings).

Unknown

but why do that? straight boiler reset down to 130-140 doubles the run time of his BB zones at lower temps. longer run time = closer to steady state = more comfortable, and more efficient to boot.

I don't see the benefit of "full-range" reset with baseboard. Technically it's superior of course, but in the same way that using a zone per room is; technically superior, but realistically rarely worth it. Especially since at the range you're talking about, you're probably below whatever your boiler's minimum modulation level is for the heat load of the building and you start cycling anyway.

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Steve_35

If you make a change

from BB to panel radiators you will get an increase in comfort. If you make a change from panel radiators to radiant floor or other radiant surface you'll get another increase in comfort. In each case I'm assuming the installs are correct.

The degree in comfort you achieve will depend in part on your house design. Lots of glass? Big gain in radiant comfort.

The value is in the eye of the beholder.

Our current home is 18 years old with BB. I installed a new shop this past year with a radiant slab. Our next house will definitely have radiant floor. It says something, I'm not sure what, when you're shop is more comfortable than your home. BTW, temp in the shop is 66. Temp in the home is 72.

Tony_8

Mark

Radiant floor is IT. Properly designed and controlled it can't be beat.

Bbd is still miles ahead of FHA. If you design a bbd system at a lower design water temp than 180, it will perform VERY well with a condensing boiler. It will condense MOST of the winter even designed around 180. A good condenser will use more than 10 % less fuel than a std CI boiler. The ratings are screwy and not always indicative of true efficiency.

I recently did a job (in WNY), that has radiant slab in the garage and basement, Joistrak on the 1st floor and bbd on the second floor. It all runs at 130F design temp water on a design day. Fired by an Ultra. Tstats at 65 and VERY comfortable. No need for Tekmar anything. Just waiting for an occupied winter for accurate fuel usage readings.

Lots of options and ways of doing things to get the desired result.

Mark Adams

Chuckles...

..this home begins construction next month, so I'm not replacing anything. Just trying to find the sweet spot where expenditure and comfort curves cross :-) Having never been in a home with radiant floors, just a basic HWBB or two and the usual oversized one speed FHA, my mental database is limited.

Mark

Mark Adams

Tony..

..regarding AFUE, I read somewhere that Rich Trethewy said that the AFUE test favored lightweight boilers. I cannot remember any details. Seems to me that using a standard CI boiler with purge cycle will "use" the extra heat thereby obviating this advantage.

Mark

Bill Nye_2

Mark,

If you put the radiant in, the only thing you will regret is not putting it in the rooms you didn't put it in.

From my personal experience, in my home which was built somewhere around 1911, I have had warm air, hydro-air, hwbb,[radiant panel base board], baseboard with and without reset, and staple up radiant floor.

What price can you assign to comfort? Like beauty, comfort would be in the eye [or feet] of the beholder. Once experienced, warm floors are something you would not easily give up.

I would forego the slab of granite counter top or the fancy chandeliers for radiant comfort any day. You can always add fancy later, sometimes you only get one chance to do radiant right.

when you cheap out on the controls or piping the end result, comfort, is not often experienced. When you are most comfortable you do not notice the heating or cooling system at all. No drafts, no hot or cool spots, no noticeable temperature swings or cycles.

Hydronic nirvana or utopia, zen heating. I guess you had to be there.

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Tony_8

the opposite

AFUE favors CI boilers. In my experience, a low mass boiler with a comparable AFUE will use less fuel overall. About the same on design days, and markedly less the warmer it is outside. It's all in the pick up of the mass after extended off times with not enough jacket insulation to retain the leftover heat, and thermal conductivity of copper vs CI. I don't think I'd purge a CI boiler, I'd store the heat for the next cycle.

Tony_8

Bill Nye's got it right

Troy_3

WNY

Requires more than 4 months of heating for most of us. My system has been on for 6 months so far. And it is 32 deg. this morning. Hydronics give you comfort. Forgo the A/c if you want to save a few bucks. That is needed about 10 days in WNY for an average summer. Why sacrifice comfort for 7 months so that you are cool for 10 days.

PJO_6

Other Questions...and opinions.

Mark,

Since you are looking for both comfort and efficiency, here a couple of things I haven't seen yet.

1) What kind of fuel will you use? This most certainly has to affect your decision. If it's oil, it's tough to go with a condensing boiler because the Monitor FCX is the only one available I believe...and it's pretty expensive...won't suit your "90%/50%" philosophy.

If it's propane, then you should weigh the differences between oil and propane - and non-condensing vs. condensing - very carefully. Here in SE Pa, the difference between the two fuels is noticeable (oil is still cheaper), and remember that oil gives you about 40% more btus per unit. The slightly higher expenses in maintenance for oil still leaves it in favor IMHO.

If it's piped-in natural gas, then get a condensing unit, and size your baseboard for the lowest temp. possible...it's pretty cheap compared to fuel and the lower the return temp to this boiler, the better.

2) I didn't see any mention of a modulating boiler if a gas-fired condensing unit will be used, although it's probably inferred in the discussion. You will not only take advantage of higher efficiencies all the time, but also there is a good argument that when the boiler is exactly matching the load you get consistently less fuel usage as well...plus better comfort.

As for the radiant, the Wallies have spoken...I have a mix of BB and radiant in my home and it's wonderful.

Just my opinions, and I am not a contractor.

Take Care, PJO

hydronicsmike

not commercial....

...although commercial jobs will use this tN4 system as well in the future. A Boiler Reset Module 420 is even slightly less than the 260 and the Zone Manager is roughly the same as your Relay Box you are currently using. The only item adding cost would be the thermostats, but those are communicating. The communication is what offers you so many more features and functions that you cannot get from a standard thermostat and therefore truly Integrate your system and achieve maximum efficiency.

Yes, I am sure. I am the tekmar guy who just blew past you in Buffalo. Sorry to have missed you. Call Baker Associates for pricing, or tekmar for more info at 250-545-7749.

Mike

Ted_9

What pitman9 said is what I'll say. Use the panel rads with TRV's and constant circ. Use outdoor or indoor reset. Cast iron boiler and you be happy, comfortable and have control in each room. With panel rads, you ge convective and radiant heat. You only get convection from copper fin tube.

Other wise go radiant,

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Mark Adams

I shoulda guessed...

the opposite. George in Seinfeld was right :-) At any rate, I found some neat links to papers on the subject.

http://energykinetics.com/pdf/AFUE position paper.pdf

http://mzboiler.com/contractors/study.html

Yes, they are slightly biased, but the principles are correct. As for purging the heat from a CI boiler, I think it would make sense to do so for indirect DHW production in the summer and to not bother in the winter, especially if the boiler is in a basement.

Mark

Mark Adams

PJO..

.. the fuel choice here will be propane. Right now in WNY oil is only a tad cheaper. Yes, 40% more BTU/gallon but also 35% more $$/gallon. Add a bit of extra maintenace and its nearly a wash. Now I could install lots of oil capacity and buy the oil in July, but I am hoping that NG will be coming through within the next 5 years or so. Another factor is the new lower sulphur oil that will be coming soon. I imagine that will be more expensive than the present blend.

As for a modulating gas unit, the prices are very high and do not fit into my 50/90 model :-)

I'm still thinking a mix of BB and underfloor radiant with a "standard" boiler. If all goes well, I'll replace the boiler when I'm 85.

Mark

PJO_6

I'm confused...

Forgive me, but if you say oil is a "tad cheaper" then you say "35% more $$$" in the next sentence?

Also, the Munchkin, for example, is about 15-20% more than a "regular" boiler. Your costs may vary! :-) If you are living in that house for a long time, that will surely pay for itself...and be more comfortable...and when the gas pipe comes in I believe the changeover is almost nill.

Other guys have MUCH better input on this...ME, PAH, and many others can tell you more.

If it's oil, then you could get two tanks like I did, and I need two fills a year...if it's a perfect world it's late August (cheapest) and then I pre-pay for the balance of the year right then. Saved me about $150.00 average per year or so.

If I could do it over again, I would have put in a double-walled 1,000 gallon tank...but that's hindsight.

Also, can you talk to a contractor about possibly doing some of the labor yourself to rough-in a radiant zone or two? That would save you some bucks if he's willing. Seems to be a trend lately...

Take Care, PJO

tony the tech

Panel Radiators

Ted,
What manufacturer do you like for panel radiators?
-Anthony

jerry scharf_3

where's the 90% point

Mark,

That's always the hard question. If I were building a house for good comfort and a 90% target you speak of, it would look something like the following:

Boiler is a small to moderate condensing boiler. depending on the time of year, these will run in the 90-96% range, so your fuel savings will be better than you suggested. I won't dip into the brands here. Indirect hot water tank off the boiler for DHW.

radiant for tile surfaces. panel radiators with thermostatic radiator valves for the rest. This makes each radiator into it's own zone and gives you great comfort.

Controls are something like the new tecmars. You want two outdoor reset curves, one for the radiant with some form of mix-down and one for the radiators. Radiant zones use zone valves with a single pump and pressure bypass. Radiators use a second pump in constant circulation with pressure bypass as well.

Don't forget to add am ERV into the picture.

It's actually a pretty simple setup and will return comfort that everyone will rave about and good operating costs. I'm not sure what it would be 50% of, but it's certainly not gold plated.

jerry

Weezbo

Have you considered a Triangle tube>propane<? solo 110

LP .There is a very tidy resource user...chosing radiant emmitters , in the slab your going to be conducting heat to thermal mass and have the chance to put btu,s exactly where youd like them to be basically.do an erv or hrv in your area for indoor air and the hepa. you might live that long *~/:) if your building for yourself the triangle tube has the control built right in like an Ultra,with outdoor sensor....the boiler modulates down or up really cleanly...instead of a water maker,indirect,or heat exchanger,the renai might be another dollar i would invest,it is also available in a propane model,the beauty of the two is with an insulated heat exchanger one could add or cover for the other basically a system that has the ability to fully cover any brief outage of either appliance .... this lash up might be a system that would provide you the least amount of energy consumption practical with redundancy...it is just a thought...maybe you would do well to consider these appliances in your home either or both.look into them..the SOLO 110 lp Triangle Tube is clearly built with this century's knowledge...good luck.

Ted_9

Buderus, DiaNorm and Runtal panel rads.
I've also seen these, but I havent used them yet http://www.roca.radiadores.pl/rocaweb/gb/htm/i2_g.htm

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clammy

munchkin & baseboard

How about saving money besides condensing it also modulates saving coin just use cast iron rads or baseboard or commerical baseboard like slant fin 90 do your room to room heat lose size your basboard to about 160 temp and get the munchkin with the vision one outdoor reset and use a indirect hwh for the portable now youyr talking fuel saving and no masonary chimmey to worry about you can make your home tight because your using out side air for combustion .I,ve installed a system as per discribed and the HO loves it cut there gas bill in half .The small amount of extra money you spend on the munchkin you'll save on a masonary chimmey and all the other reset controls you planned on using i believe it would be cheaper in the intinal install over a ci boiler with direct vent plus that combustion fan on most ci boilers is much louder then the silence of a munchkin in fact there unit is so quite i'm planning on changing my boiler to a munchkin this summer i was hammered by my gas bill this winter .It's a wise choice to check out throw that in your optians bag peace clammy good luck

S Ebels

Think new thoughts

This is the twentyfirst century you know. Rising fuel costs, questionable supplies down the road......

Forgive me for being blunt and maybe I'm WAAAYYYYY off base here but this is so typical of new construction. I realize you want to get the most bang for your buck, doesn't everyone? But..... installing a non condensing, non modulating boiler is stone age thinking. Whether you are using gas or oil as fuel is immaterial. What you need/want is a boiler that will modulate down to 70* shutoff without the aid of a mixing valve. This is the best for efficiency and it doesn't have to be expensive if installed correctly. I'd chuck the baseboard too and go with panel rads for a number of reasons. Such as better low temp comfort, less wall space required, options for heated towel bars, and most importantly, simplicity of design and piping. You can have as many zones as you want with panel rads using only one circ and no zone valves. Just put a TRV on each rad and presto, instant zone.

Heat you whole house using only 60 watts of electricity to move the water. No zone valves to puke out down the road. One small constant run circ just purring along. This morning at 31* outdoor temp my boiler was running 94-110*s, the rads were just nicely "idling", perfectly matching the heat requirements of the rooms..........AAAHHHhhhhhh, heating bliss! A constant 72 in the house just as even as you please, no rice krispies sounds that always accompany an on/off baseboard cycle. No hassles with mixing valves or extra injection pumps, nothing but silence and proportional output of heat from the rads. We've only done one BB install in the last 2 years and that was a replacement. Rads with TRV's are the way to go. Check out www.hydronicalternatives.com and look at the Radson line. If you can't find anyone locally that will give you a decent price, e-mail me and I'll get you set up. No problem. Easy to install, easy to pipe, easy to control, virtually no maintenance. What more could you want?

Forgive me if I sound rude or condescending, I just get a little sideways about people not putting in the best possible equipment for their budget. A munchkin running panel rads is very efficient and not as costly as you think. The payback is there.

I apologize in advance if I offend in any way. e-mail me if you'd like more info.

Mark Eatherton1

What Steve said...

and more..

How can you put a price on "comfort"? How do you value comfort? What IS the definition of comfort?

Working backwards, My definition of comfort is "not being aware of your surroundings". You are neither hot, nor cold. You're not hearing anything, and you're not feeling anything. You're just experiencing "comfort". Is it free? NO..

Is it worth the uptick on the installed cost? YOU BETCHA (How's that for unbiased:-))

Look at the opposite potential. You are not comfortable, you hear your heating system all the time, and feel the chill. You are not a happy camper, and the only thing that stays on your mind is the price you paid for this "lesson". That's the good news. The bad news is you didn't get what you bargained for. You wanted comfort and you got discomfort and high utility bills, and lot's of noise...

We have a saying in this business, it goes "It's not so much a matter of "Ya got what ya paid for" as it is, "You'd didn't get what you didn't didn't pay for, and now in order to acheive your goal of comfort, you're going to have to pay me MORE money!"

If we had had a conversation early in the "budget process", I might have been able to explain what your contractor DIDN'T include, and we wouldn't be having this conversation. Bottom line, you'd have paid me as much money as you're going to have wrapped up in this baby, we wouldn't be having this conversation now, but you wouldn't have had to "put up with it", and you could have spent that time doing something else, like perusing the sattelite mapping systems on the internet.:-)

What price comfort. Most of my customers know comfort. The few that don't know why they don't.

It's your money. Spend it now and get it out of the way, or "put up with it"?

Here's what I want the entrance to my office to look like so I can keep up with Ken's idea of how lavishly I live... Can you see the Testerosa in the reflected image of the heat exchangers?

Ahhh. Comfort:-)

ME

jerry scharf_3

tell us about well insulated

As insulation is the most cost effective way to save on energy costs, why don't you run down your plans in this area. I have some opinions on this and I know others here do as well.

I'll give you my first opinion before you start. Bat fiberglass insulation isn't worth spit.

jerry

S Ebels

I'll second that!

You might as well stuff your walls with wadded up newspaper. Go foam or dense pack cellulose or go home and give it up.

People that utilize "standard" construction practices of today are going to find themselves making energy payments in the same $$.$$ range as their house payment in the 5-10 year future. Scary thought.

S Ebels

K2

I think your 50/90 model is flawed. It might make sense today but apply it to fuel costs 2-3 times what they presently are. How does it stack up when you can't afford to keep your house at 60* and make your motgage payment at the same time?

There may be temporary downward blips in fuel prices but the general outlook in the not to distant future is nowhere but up, substantially up.

Mark Adams

S Ebels,

I've used 7%/yr as my guess for future energy prices. This equates to a doubling in fuel costs every 10 years. If you were to assume even greater than this, you'd have to be looking at insulated glass windows, foam insulation, passive solar, active solar for DHW, etc. There are only just so many ways to spend a finite amount of $$. It's a tough call all the way around.

Mark

Mark Adams

FOAM!!

Yes, foam is my choice. Healthy Seal, Sealection or Icynene. Just waiting on the final quotes.

Thanks,

Mark

jerry scharf_3

I prefer closed cell foam

Mark,

Now my opinions will start coming out.

I don't know what the costs are in your area, but the costs per sqft. for a given R value wasn't much different between closed cell and open cell foam for me. Closed cell foam that has vapor barrier level permeability is by far my first choice in foams. With a skilled installer, I think it goes in as well or better than the open cell stuff. Corbond and Resin Technology are two brands that I am personally familiar with. Sadly, these do not meet fire and smoke codes and need to be covered with sheetrock or other 15 minute fire barrier. Be careful when comparing, not all closed cell foams are low permiability (or permeance to be exact.)

The reason I am somewhat concerned with open cell foam is that there is a dew point that will form somewhere in the foam, and that has the mold person in me worries about that.

jerry

Mark Adams

Jerry,

I did not consider closed cell. Up here, even the guy that installs it will not put it in the walls of a new build. He'll only use open cell for that.

Thanks,

Mark