Heating solutions

<div class='quotetop'>QUOTE(maggieddd @ Feb 7 2007, 08:17 PM) [snapback]386803[/snapback]</div>

Well, you'll pay line charges and infrastructure fees in addition to a meter reading fee regardless of how much gas you actually use. Is your water heated with gas? Do you have any pilot lights?

80% is pretty much the bare minimum for modern (after 1992) furnaces.

 

<div class='quotetop'>QUOTE(jayman @ Feb 6 2007, 04:22 PM) [snapback]386407[/snapback]</div>

In the interests of fair disclosure, I work in the boiler industry for a competitor of Weil McLain. What I am about to say applies to all high efficiency boilers in the industry, including the ones my company sells.

The efficiency of a condensing boiler like the Ultra is on a sliding scale, and you are likely to never see the higher efficiencies. In order to obtain that 98% efficiency rating, the return water temperature has to be very low ... around 80°F. Because you would never run a radiant system at that low a temp ... because you wouldn't get enough heat output ... you will probably have your radiant system returning water at 130 - 140°F. I don't have the curve from the ASHRAE manual in front of me here, but I think the efficiency curve at that temp is around 90%. That is 6 to 7 percentage points higher than non-condensing boilers that cost far less. Thousands less, when you consider installation and maintenance costs.

I don't believe that Weil McLain was among the manufacturers who published incorrect data on their marketing materials, but they may have trumpeted those higher efficiency ratings for systems with very low water temp. These systems do exist, such as in ground source heat pumps, snow melt systems, etc., but in residential homes using either hydronic radiant tubing in the floor, walls or ceiling, or in systems utilizing radiator or baseboards, the return water temperature is substantially higher (130 - 140F).

Because of the confusion created by marketing materials trumpeting the higher (and usually unobtainable) efficiency numbers, the Gas Appliance Manufacturer's Assoc (GAMA) issued a letter on 9/1/2006 warning member companies about overstating efficiency claims:

Member manufacturers had until November, 2006 to cease and desist using the I=B=R Certification Seal and those high efficiency claims. Check the date on the technical info, and look for the I=B=R seal to ensure the product has been tested to the DOE test procedure and BTS-2000.

There is no free lunch, and there is no hydronic boiler that will deliver efficiencies higher than the curve in the ASHRAE manual. The laws of physics apply.

 

<div class='quotetop'>QUOTE(maggieddd @ Feb 7 2007, 08:39 PM) [snapback]386825[/snapback]</div>

The efficiency curve in the US is "100 based", so that if you used every single BTU of the heat to heat the room, you would have 100% efficiency. A glowing red electric element will transfer 100% of the heat into the room.

A furnace that is 80% efficient uses 80% of the heat to heat the room, and 20% of the heat is lost either up the stack or through the walls of the furnace. A 92% efficient furnace adds 12% to that, so that you "waste" only 8% up the stack or through the walls of the furnace.

The math is a bit harder than this, but you can make a quick and dirty comparison just with those numbers. In theory, you would lower your gas usage by about 12% with a 92% efficient furnace. (BTW - I have no idea if the hot air furnaces are really that efficient or not, so ignore my post about hydronic boilers in regards to your system).

This isn't exactly what you save, but its close enough when you are trying to decide about ripping out a $3000 system to install one that costs $8000. Is 12% of your yearly heating bill enough to pay for that $5,000 delta over 5 years?

 

<div class='quotetop'>QUOTE(maggieddd @ Feb 5 2007, 08:15 AM) [snapback]385520[/snapback]</div>

A cigarette would work, but reeks. There is something called "punk" which works, but you may not find easily.
Also, incense.

 

<div class='quotetop'>QUOTE(maggieddd @ Feb 5 2007, 08:56 AM) [snapback]385569[/snapback]</div>

Drive your Prius into the house. When your cold go in the car and turn on the heat. You can sleep in their too. Be sure to connect the exhaust to outside the house. If you park it in front of the TV the TV remote control should still work as well.

 

Visit the Rocky Mountain Institute, www.rmi.org, for many cost effective solutions.

 

Here's that efficiency curve for one of my products ... it would be the same for all condensing gas boilers. You'll note that the highest efficiency is at 70°F inlet water temperature (the axis along the bottom) where, when the boiler is at the lowest modulated setting, it gets in excess of 98% efficiency.

But when you get to where most "low temp" systems are operating in residential homes, in the 130°F to 140°F range, the efficiency drops off to 90 - 92%. Still better than the 82 - 83% efficiency of atmospheric, non-condensing boilers, but these are a lot more expensive too ... a 120,000 BTU/HR condensing gas boiler we sell has a list price of over $5,000, whereas the same size non-condensing boiler is under $2,000.

Is saving about 10% on your gas bill worth $3,000? That's the question you have to ask.

 

<div class='quotetop'>QUOTE(maggieddd @ Feb 7 2007, 11:02 PM) [snapback]386792[/snapback]</div>

No no, after I take a load out of the dryer it's still nice and warm and he likes to hop in and nap for awhile. I'm quite careful about making sure he's out of the dryer before slamming the door shut

<div class='quotetop'>QUOTE(maggieddd @ Feb 7 2007, 11:17 PM) [snapback]386803[/snapback]</div>

Are you on some sort of equalized payment plan? Around here it's common to "average out" the utility bills so most folks don't get a shocker of a bill in winter. I prefer to pay for actual use. In that case they estimate two months, and read the third month. I call in an actual reading for the months they would estimate.

It could be the $40 is also some sort of minimum charge. Back when Ontario Hydro did the Enron thing, promising rate payers nothing bad would happen, something bad did happen. The bills shot up, more than doubled for most people, and the minimum "service charge" worked out to be around $25 a month. Once you factored in the "debt retirement charge" the bill really went high. The entire Board of Directors resigned after that Whoopsey Daisy, but naturally they still kept their solid gold options and pensions.

 

<div class='quotetop'>QUOTE(fshagan @ Feb 8 2007, 01:53 AM) [snapback]386840[/snapback]</div>

I should explain how my neighbor set up his system.

His house is slab-on-grade. He had an engineering analysis done on the site to determine how suitable the soil conditions were. They claimed with compacting the slab should be fine, but we’ve seen the results of other neighbors basements and driveways.

So he had piling done to the main slab and the garage slab to be on the safe side. After piling and compacting, we then proceeded with the slab pour.

The primary slab is 4 inch. We applied the Beaver Plastic Frost Cushion before pouring, so in theory there is already an R-20 under the slab. On top of the slab we applied the Beaver Plastic 2 inch hydronic thermal barrier. The hydronic thermal barrier is neat, it already has channels molded in to accept the PEX hydronic tubing.

So once the tubing is laid out you then do a lightweight pour of about 2 inches, mostly gypsum so it sets within 30 mins. The exterior walls are same as my hobby farm: ICF finished width 12 inches. Ceiling is SIP 6 inches, which is nice as the gyproc is already on the ceiling side so much less finish work involved. He still had R-40 blown in on top though. The windows are all Polar Window tri-panes with dual argon and dual low-e: very small windows on the north side, large windows on the SE facing living room.

The flooring throughout the house is tile. He immigrated to Canada at age 20, and having been born and raised in Paraguay has some sort of instinctive fear of carpets. I guess creepy-crawlies live in carpets down there. So for maximum heat value tile is about the best to use for radiant heating.

There is also a thermal break of 2 inch closed cell Styrofoam around the perimeter of the slab, and a thermal break between the house slab and the attached garage slab.

If I recall, the system is set up for three zones: two for the house and one for the garage slab. The garage slab is run through a separate heat exchanger.

So in this situation the system appears to work best at the low return temp. When first started in late fall, the floor heats up within 15 minutes. The floor to me feels comfy warm, never hot. I know their cat likes it.

I’m invited to their place Saturday evening for a feed. If you wish, I could borrow an IR gun from work to check their floor temp.

 

<div class='quotetop'>QUOTE(fshagan @ Feb 8 2007, 02:07 AM) [snapback]386842[/snapback]</div>

An excellent point. If nothing else is done to the house, then the answer is a very firm NO.

Let’s consider the home I built at my hobby farm.

The walls are ICF with a finished width of 12 inches. Ceiling is very well insulated. I would suggest to anybody in an extremely cold climate to consider ICF, with SIP for the ceiling. Also use a continuous peak vent for the gable roof, you really do need to keep the attic well ventilated to avoid frost/ice issues if you hope to get any sort of life from the shingles. Avoid a roof design with complicated peaks/valleys, unless you like ice dams

I have a porch for the main door, which faces south, and a “three season†enclosed patio for the rear door, which faces north. So the doors never see direct weather or snow/ice. All the windows are from All Weather Windows, their “Arctic†series tri-pane with dual argon and dual low-e.

I went with a forced air system. In hindsight I should have gone slab-on-grade and hydronic, like my neighbor. Oh well, next house I suppose. I put in a Bryant Evolution system: Plus 90i furnace 60,000 BTU input, Evolution two speed two ton A/C, Bryant electrostatic air cleaner, GeneralAire HEPA auxiliary air cleaner, Evolution control system, and Bryant two speed HRV. The water heater is an electric Rheem Marathon 50 usg.

I needed the HRV because the house is so airtight I would have IAQ issues without one. I went with the HEPA auxiliary system, which takes a portion of the return air and sends it through the HEPA box, because I’m picky that way. It’s not like I had any debts to worry about, so I went for quality and long-term.

Everything installed for the HVAC came to $18,000, including labor for sheet metal ductwork, plus taxes. Like any reasonably smart consumer, I shopped around and got a few quotes, comparing my Ultimate system with a bargain basement system. I could have had a basic 80% furnace, but even with an insulated fresh air duct to supply the furnace, I was worried about possible backdrafting due to how tight my home is.

The basic system (80% furnace, SEER 12 basic two ton single speed A/C, basic heat/cool thermostat, basic humidistat for the HRV, basic HRV, no fancy air cleaning, etc etc) would have cost me $13,000 plus taxes. My combined annual gas/hydro is $1,600.

Was it “worth it†in terms of utility bill “savings?†Of course not! Not even a climate where it can dip to -40 in winter. Using an energy audit on the house plan, courtesy of Manitoba Hydro, it was calculated a ROI of almost 7 years with current gas/power rates.

However, I’ve been in homes with those bargain-basement systems. Furnace fan roaring away, huge gush of air from the registers, noisy outdoor A/C unit, etc. I really like the fact that 99% of the time, the only way I can even tell if my system is “on†is if I walk right up to the furnace and touch it, to feel the slight vibration from the inducer motor. Or look at the peephole to see the blue flames.

So for me, there are subjective “touchy feely†things involved, not just the initial cost. I appreciate what you’re saying, and mostly agree with your statements

 

<div class='quotetop'>QUOTE(jayman @ Feb 8 2007, 06:33 PM) [snapback]387225[/snapback]</div>

Sounds like he has a first class job! That's really outstanding the way he has it set up. He will get the most out of the system with the great insulation of the slab.

The efficiency curve works on temp of the water coming into the boiler to be heated. While the floor may be 80, 90 or 100F, the water in that pex tubing will probably be hotter than that. Usually, the systems have to run with outlet water going to the slab at 150 - 160F, and coming back at 130 - 150. So if the system is running, check to see how hot the water coming back is; another way to tell if he's in the higher part of the efficiency curve is if there's a lot of condensate pouring out of the condensate drain.

The condensing boilers obtain higher efficiency by extracting the heat out of the water vapor in the flue gasses ... ever felt the steam rising off a pot of boiling water? There's a lot of latent heat there, and when you cool that steam, the water vapor does a phase change back into liquid water. (This analogy is not quite right, but close: the boiler isn't "boiling the water in the pipes" to produce that water vapor. The water vapor in flue gasses is a result of burning the natural gas or LP gas molecue; one of the byproducts is H2O in vapor form).

One way to tell what efficiency the boiler is actually operating at is to see if there's condensation forming (i.e., that phase change is taking place). If there's no condensation visible, he's somewhere between 83 and 90 percent efficient (at about 84 percent, the condensation starts to form, but is often burned off before collecting, so there's some margin in there that says, even without visible condensation, you could be in the higher part of the curve.)

 

<div class='quotetop'>QUOTE(fshagan @ Feb 9 2007, 02:12 AM) [snapback]387318[/snapback]</div>

I was able to "borrow" the FLuke 576 from work, so I will do as you request and check the boiler manifold, and some spot checks of floor temp.

Now that you have me thinking of this, what I would *really* like to do is borrow the new FLIR Systems ThermaCAM P640 from work. We recently took advantage of FLIR's trade-up program and the P640 is a neat little gadget. That idea may have to wait for a month or so

Expect to hear back from me Sunday evening

 

Didn't you say your furnace was new? Unless your plan is to use it in a remodel of the second floor, it would be kind of expensive to replace a new furnace, but let's see what the experts think.

Dennis

 

my house is from 1877-

shrink wrap the windows will help alot- don't keep it on in the summer, it doesn't last. However, I understand there are interior plastic storm windows that you can buy.

talk to your landlord about your heat loss. there may incentive programs to increase efficiency.

do you have ceiling fans? reverse the direction for the winter so the hot air is forced down from the ceiling.

I keep my heat at 60 when not home- 63 or 64 when home , (the upstairs is always warmer) I think that very large swings in temperature of thermostat are actually less efficient since it has to work much harder to bring up 20 degrees.....just my opinion