Ideas for saving energy

[franck@geneseo.net]

I recently purchased a Marathon water heater for my new home, which is currently under construction here in northwestern Illinois. When making my decision on purchasing a water heater I considered several factors, none the least of was the fact that my power company offered me a $125.00 rebate on the purchase of an electric water heater. In addition to the rebate I liked the idea of a rust free, wound fiberglass tank. We live in the country and our well water is a bit harsh. Also, by going electric I don't have to worry about the installation and expense of a flue, the safety issues of a malfunctioning gas burner, the energy loss of an always open flue or replacing the combustion air.

Our new home is 2,200 sq. ft. with a standard kitchen, laundry room, two full baths with an optional third bathroom once the basement is finished (in a few years.) Currently, it's just the wife and I (unless one of the kids moves back in.) I opted for the 85 gallon model. It should meet all our needs.

Here are some thoughts I'm tossing around to reduce my energy useage.

I'm considering running a few hundred feet of 3/4" PEX water line through the attic space in an effort to "temper" the cold water supply going into the heater. In the warmer months I'm hoping to raise the ground water temperature 30 degrees or more. I am also considering placing an insulated storage tank in series with the water heater to hold this "tempered" water. I just hate to see all that heat generated in the attic going to waste. To add a bit of complexity to this set up I'm thinking also of adding a thermostatically controlled recirculating pump into the loop. Not being a CPA I haven't crunched any numbers so I don't know if the cost of running the pump outweights any energy savings of pre-heating the water going to the heater.
To prevent damage in the colder months I would plumb the loop so that I could isolate the attic lines. This would allow me the ability to drain and flush the lines using compressed air.

During the heating season we intend to supplement our heating requirements with an outdoor wood-fired boiler. As those lines feed into the house they would pass through a heat exchanger in the furnace plenum, then through a coil wrapped around the afore-mentioned tempered water storage tank and finally through a series of heating coils under the kitchen and bathroom floors, then back to the outdoor boilder, all as one, continuous loop. I would include the ability to isolate the floor heating coils in the event that it's too much warmth. We don't want to cook Mama's feet with too much heat radiating up through the flooring!

One last item I would like to install, and this is more creature comfort than energy savings, but it would be a gravity flow, hot water re-circulating system plumbed to the bathrooms. At this point, what's one more line and a bit of insulation?

I can see a potential for cost savings with a very minor expenditure. I guess this all falls into the catagory "experimantal plumbing = research and development."

So, for all you good and gracious professional plumbers, what do you think of my ideas? I know it's a lot of tinkering, but I am retired and enjoy that sort of thing. I look forward to you input. After all, you're the pros! :)

[franck@geneseo.net]

I did some looking around and found another tread that speaks to some of my ideas.
http://www.terrylove.com/forums/showthread.php?t=26627

If I did use a re-circulating pump, what make and model might I be looking for?

[chris8796]

I wouldn't run PEX through the attic, too many potential risks for such a small reward. You could do a DIY solar setup for a little more money and have very little risk.

I don't have a lot of experience with boiler systems, but I'd want the sub-systems to be controlled individually. They all have different preferred temperature ranges and heat loads. Most of the wood boilers I've seen are coupled with a large heat storage tank (~1000 gals). This gives you alot more flexibility and makes it easier to use wood in the spring and fall, even in the summer for DHW. It also helps in preventing smoke, since you can burn at a constant high rate. Rather than constantly going into idle mode, which tends to produce alot of smoke. In general, wood boilers are only for those deeply commited to burning wood. The biggest complaints I've seen is, the smoke, the volume of wood and the labor to move it, daily monitoring, must constantly feed it and protect it from freezing (you can't take a day off). I think this makes these a poor choice for most people. This a way of life rather than a method of heating.

[franck@geneseo.net]

I do understand the drawbacks of operating an outdoor wood boiler. We have used a home built airtight wood stove exclusively for the past 30 years to heat our home. There is a like new, 30 year old Heil gas fired furnace sitting in the basemant of the old house. We turned the pilot light off 29 years ago and haven't re-lit it since. And yes, I keeps you married to the woodstove 24/7. I'm assuming the outdoor wood boiler will require more wood to heat our new home than our trusty airtight, but it will allow us the flexibility to go on vacation from time to time, provided we don't have an electrical outage. The circulating pump on the wood boiler runs 24/7. Should the fire go out, the gas fired furnace kicks in and keeps the boiler loop warmed through the heat exchanger. In theory it shouldn't freeze.

Chris, what drawbacks to the attic loop are you concerned with? Leaks? Installation? Cost? Weight? Using PEX? Please elaborate. I'm here for the education.

I haven't yet ruled out the solar collector idea, I just need to research it more. Any links would be appreciated.

[chris8796]

I think energy costs will need to go up quite a bit to consider wood. I'm just north of Peoria and have a 2600 sqft house. I checked our gas bills for 10/29-4/1, I used 600 therms at a cost of $658, which provided heat, HW and cooking. We average about 30 therms a month in the summer for HW and cooking (family of 4). That would mean we used about 450 therms (~$500) for heating this winter. There is no way it would be worth the capital costs, labor and wood costs for me to consider it. The coldest month we averaged less than 20K btu/hr with the thermostat set to 70 during awake hours.

On the PEX, the leak potential is the biggest problem. But you also have to consider the potential for condensation, physical stability (150 degree seasonal temperature swings). If you average 50 gals a day at 30 F temp rise, thats 13200 btu or about 4 kwh. You'll save 40 cents a day and $12 month minus capital costs (PEX, pump, storage tank, heat exchanger, lost interest income) and electricity to have a time bomb over your head. Then you only get these savings in summer. Solar has the potential for more savings, but its still really tight if you look at the numbers.

In my experience conservation and insulation has the biggest payback.

[master plumber mark]

[quote=chris8796

In my experience conservation and insulation has the biggest payback.[/quote]



No offence meant...but Marathon water heaters are not all that great


I would also insualte heavily

I got a guy who blew 6 inches of foam
insulation into all his outside walls while building his new home....

did something similar in the attic too

I am now wondering how well his winter went.....
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I would not put the pex in the attic becasue of
the condensation problems that would happen......forget about it...

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Now here is my dream solar system.....tell me what you think of it.....



If I had a the time and money, I would dig a hole somewhere in the yard and near the house, then install a large septic tank and insualte the sides of it with about 6 inches of styrofoam insuation, also you need to get it near where the panels would need to go..


this tank would hold about 2000 --3000 gallons of extremely hot water that some solar panels would be constantly heating, ...... this should give you a huge reserve to get through perhaps a few days without the sun...


this extremely hot water in the tank would be pumped into your forced air hvac system when ever the furnace would come on and pump through a heat exchanger in the phlenum. This basically can and will heat your home... very well indeed...


also you can put 600 foot of 3/4 pex down in that hot tank and use it to pre-heat the water heater.... no pump required


these solar panels work with glycol with a
100 foot copper coil for a heat exchanger sunk deep down in that water tank.... this can and will literally heat that tank as hot as hell during the day
I have literlaly seen one steaming hot before when I worked on one...



this system would work with just 2 simple pumps,
one for the soalr system, and one for when the furance comes on and
pumps the heat into the house.through the heat exchanger.
.... and just a small solar controller box..for the heat sensors....



I think this system is soooo sweet......




I myself would prefer doing this any day over cutting wood and keeping a wood shack constantly burning all winter long...
remember if you have neighbors, they can get
very tired of looking at that shack throwing smoke into the air all winter long.






just another idea ...

[franck@geneseo.net]

Hummm, how about pumping all that heat into an indoor pool, then drawing off that? Seriously though, it's an interesting concept. Are you thinking of a focused parabolic mirror to heat the water? How big of a collector are we talking about?

[master plumber mark]

all you need is an array of solar panels
sitting out in the yard faceing south right above that
tank... the actual amount of panels would have to be calculated to the amount of water you want to boil

my best guess would be 4

The roof is good too, but if you have the room and they dont stand out too badly in the yard, I would perfer to have them on the ground..

also for that matter you could use that wood shed boiler to heat the water tank in the yard.....


this is actually a very simple system to maintain...

much easier than chopping wood for the rest of yourlife....

.unless you like the exercise

[chris8796]

A massive storage tank is important if you hope to provide the majority of your heat with solar or similar. I also like the idea of keeping the panels off the house and in a place with easy access. In the midwest, we get about 3 kwh per m^2 per day in the middle of winter and 5-6 in the summer. Its important to minimize your heat use/loss as much as possible. I would also consider a radiant system, just because it can utilize lower temperature water than FA. This increases the usable storage capacity of your tank.

[jimbo]

.

.......a few hundred feet of 3/4" PEX water line.....
That will drop your water pressure by about 2/3. You won't waste much water in the shower, because it will only dribble.



...... outdoor wood-fired boiler.
Now there's a concept which will set the entire clean air effort back to the dark ages.




You need to rethink some of your ideas, and get some professional design help.

[master plumber mark]

Perhaps you are right about losing some pressure on
the hot side of the system,

it depends on how much pressure you have to start with, and how much you are willing to give up to
passively heat your hot water tank...

I would have to try it to see , I doubt it would be all that noticeable....


hell, if the fellow wanted to run that much in the attic, I dont see how it could be any worse


we got to go green, green, green

[franck@geneseo.net]

OK, You've talked me away from the attic heat recovery theory. I can see the problems of potential leaks, condensation and the meager returns for the effort invested. I will investigate further the benefits of passive and active solar heating.
This leads me to another question, radiant heat. I have yet to pour the basement floor. Would it be prudent to embed a radiant heat system for future use? Initially, we will incorporate a forced air furnace (I already have it) to heat the house. As mentioned earlier there is approximately 2400 sq. feet of floor space on the main level with a near equal amount of space in the basement. How long should I expect the investment in a solar collection, storage, and radiant system to pay for itself (roughly).
If I can find a workable solar solution I would gladly give up the idea of an outdoor wood boiler and it's associated drawbacks.

[Gary Swart]

Sorry in advance for a negative attitude. I know that "Going Green" is the hip thing to do nowadays, but I can help noting that the old adage of "Penny wise and Pound Foolish" applies to many of the attempts to conserve resources and money. The best return on your dollar is additional insulation and otherwise slowing heat loss.

[jadnashua]

I'd seriously consider embedding a suitable pex tubing (requires an O2 barrier) in your slab. Depending on the size, you may need multiple zones (loops) to keep the heat even. As is true with any slab, prep is crucial, especially if you ever want to heat it. You need to keep both moisture out and provide insulation to the slab, as wet insulation will draw off the heat.

[master plumber mark]

How long should I expect the investment in a solar collection, storage, and radiant system to pay for itself (roughly).
If I can find a workable solar solution I would gladly give up the idea of an outdoor wood boiler and it's associated drawbacks.

to figure out how long it will take to break even on
the solar systems out there it all depends on who you ask...

ask a solar salesman and he will have some figures for you.... take whatever he says the payback will be and add probably %30

understand that at best, you are only going to
cut your heating bill down by probably half,, maybe more,
but you will never be totally free of your dependencey on the grid ,

unless you want to cut that wood all winter long....

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another very feasable option that would work great in a home with a basement would be a large wood burning stove in the basement.....centrally located......

you would be suprised how well that works...

I have just 2 plain old fireplaces and I can keep my home pretty warm on the nasty days.......

[hj]

That electric heater could "use up" the $120.00 rebate in increased energy costs in a matter of a few months. A coil wrapped around a tank will have such a small contact area that it would not even be worth the cost of the material to do it. A recirculation pump is NEVER energy efficient, it is a comfort item and will also add to the energy costs. A thermostat controlled one, if done in the conventional way will measure the temperature of the returned water at the water heater, not at the faucet where the water is used, so the water will not necessarily always be "instant hot water".

[Scuba_Dave]

I just finished a greenhouse, 7x10 x ~6' high - less then $30 cost
With a sunny 70 degree day it was up to 107 at one point
I'm going to build a solar air heating system to go in the greenhouse & hook it up to recycle & heat house air

[SewerRatz]

I now I am a bit late in responding to your post. But I would check with your city or county codes about Pex. Illinois does allow for it but most of the northern counties do not allow pex or CPVC to be used.

About the radiant heat, if you are considering it, also look into a snow melt system for your walkways and driveway. I have helped install a radiant heat and snow melt system for the Ray Graham Center for the blind in Burr Ridge a few years back. I am really surprised with Northern Illinois cold wet winters that radiant heat and snow melt systems are not more wide spread.

[franck@geneseo.net]

That electric heater could "use up" the $120.00 rebate in increased energy costs in a matter of a few months.

Yes, I assumed that from the start, but the price of propane has gone up so rapidly here and I don't see that situation improving any time soon. That's why I'm here, throwing all these ideas around and weighing my options. After 30 years of lugging wood around I'm ready to search out alternatives. Copious amounts of insulation, controlling air infiltration, natural lighting and solar collecting appear to be my better options with the least impact on the environment.

I think I will use a secondary tank to temper the incoming cold water going into the water heater. Even raising the temperature to the room's ambiant temprature should provide a measurable amount of electrical energy savings. Perhaps an older, discarded water heater tank, stripped of it's outer shell and it's insulation would be an inexpensive solution to finding a cheap secondary tank. (Pressure tested first, of course!)

As for using radiant heat under the sidewalks and the driveway to melt snow, I'm all ears. My garage enterance faces North and I know from experience that that location is the worst for snow and ice removal as it get no natural warming from the sun. My initial questions would be how to set the system up and what type of PEX to use. Someone mentioned an O2 barrier? Where do I purchase the correct PEX and the appropriate components?

Frankly, the current administration's ideas of "Cap and Trade" scare the daylights out of me. I only see increased costs which ultimately land on the consumer's shoulders. I think we all need to put our thinking caps on and find ways, free from government interferences, to save energy and find workable alternative sources. We, the people, are good at that sort of thing.

[SewerRatz]

What city are you in, I can point you to a boiler supply company that can help you design a radiant heat / snow melt system and be able to help you with the proper materials.

[franck@geneseo.net]

Ron, (a.k.a. Sewer Ratz)
I'm located near the Quad Cities, about 30 minutes from Moline.
Thanks.

As a side note, we have been touring homes these past two weekends as the Quad Cities Home Builders Association hosts their Spring tour of homes.
I'm not seeing a lot of innovation when it comes to alternative energy. I guess new home buyers are not ready for the unconventional. They will spend a ton of money on custom ceramic bathrooms with multiple body shower heads, but not one dime for insulation around the hot water piping, go figure???
95% of the homes had conventional HVAC systems and low budget or middle of the road water heaters. Not a single water heater that I saw used dielectric unions and only a few had expansion tanks. I didn't see a single radiant heat system save for electric mats under a very few bathroom floor tiles. Nor did I see any solar panels. Only one house used a light tube to bring in natural light to an otherwise windowless bathroom.

[Cass]

Most of the new water heaters come with dialetric nipples that can have FIP connections directly connected to them...without a union...I do this all the time...

[franck@geneseo.net]

Most of the new water heaters come with dialetric nipples that can have FIP connections directly connected to them...without a union...I do this all the time...
See, I learned something new. I didn't know such a thing as a dielectric nipple even existed. But then two weeks ago I didn't know about dielectric unions either........
Once the nipple is connected to the copper, can you tell from it's exterior that it is a dielectric nipple? Not all dielectric nipples have an indentation around thier middle.
Interesting stuff, this plumbing business..........

[SewerRatz]

Most of the new water heaters come with dialetric nipples that can have FIP connections directly connected to them...without a union...I do this all the time...

Here in Illinois it is code to use a dielectric union still or brass unions. The following is from the Illinois Plumbing Code. Underlining added by me.

Section 890.350 Unions

Unions may be used in the drainage and venting system when accessibly located above ground. Unions shall be installed in a water supply system within 5 feet of regulating equipment, water heaters, water conditioning tanks, water conditioning equipment, pumps, and similar equipment which may require service by removal or replacement. Where small equipment may be unscrewed, only one union shall be required.


a) Drainage System. Unions may be used in the trap seal and on the inlet and outlet side of the trap. Unions shall have metal to metal seats except that plastic unions may have plastic to plastic seats.

b) Water Supply System. Unions in the water supply system shall be metal to metal with ground seats, except that plastic to metal unions may utilize durable, non-toxic, impervious gaskets. Unions between copper pipe/tubing and dissimilar metals shall either be made with a brass converter fitting or be a dielectric type union.

The officials in Illinois do not consider the dielectric nipples to meet the code for the connection of dissimilar metals.


Ron, (a.k.a. Sewer Ratz)
I'm located near the Quad Cities, about 30 minutes from Moline.
Thanks.

As a side note, we have been touring homes these past two weekends as the Quad Cities Home Builders Association hosts their Spring tour of homes.
I'm not seeing a lot of innovation when it comes to alternative energy. I guess new home buyers are not ready for the unconventional. They will spend a ton of money on custom ceramic bathrooms with multiple body shower heads, but not one dime for insulation around the hot water piping, go figure???
95% of the homes had conventional HVAC systems and low budget or middle of the road water heaters. Not a single water heater that I saw used dielectric unions and only a few had expansion tanks. I didn't see a single radiant heat system save for electric mats under a very few bathroom floor tiles. Nor did I see any solar panels. Only one house used a light tube to bring in natural light to an otherwise windowless bathroom.

Was their any type of union installed on these water heaters? If not the plumbing inspector is not doing his job in that area.

[SewerRatz]

About expansion tanks, Illinois only requires one to be installed if the water heater is installed on a closed system. For example if a check valve,PRV, or a backflow device is installed on the cold water system, then a expansion tank is required. If the water heaters are installed on the first or second floor of a home it would also require a Vacuum Relief Valve. Below from Illinois code. Oh a note about the Illinois plumbing code. Counties, townships, cities or any other jurisdiction has to follow the Illinois Plumbing code which is the minimum allowed, but they can make their rules stricter than what the Illinois Plumbing code requires. For example the code allows for CPVC water piping, in Du Page, Cook, and parts of Kane counties do not allow CPVC piping to be used.

Vacuum Relief Valve. Where a hot water storage tank or water heater is located at an elevation above the fixture outlets in the hot water system, or if the storage tank or water heater is bottom fed, a vacuum relief valve as listed in Appendix A, Table A (Approved Standards for Plumbing Appliances/Appurtenances/Devices) shall be installed on the storage tank or heater.

[franck@geneseo.net]

Today was the final day of the Iowa/Illinois Quad Cities Home Builders Association Spring Home Tour. I made a point of looking at all the water heaters that I could. Bear in mind, all these heaters are located on the Iowa side of the Quad Cities and fall under Iowa plumbing codes. (which I know nothing about)
There was not a single union observed on any of the water heaters I looked at. Some obviously had dielectric nipples, determined by the circular indentation around the circumference of the nipple and also the instructions on the heater itself that warned against applying direct heat to the nipple when sweating fittings. A.O. Smith seemed to be the prefered water heater in most new homes with the occasional Rudd or Rheem thrown in on occasion. Again, no one insulated their hot water runs. One home used two Rheem Marathon electric water heaters in series, plus the builder had the plumbing contractor include a hot water recirculating system that included a Grundfos recirculating pump. It worked because I went to the far bathroom and had hot water in about 3 seconds. Sadly, the hot run and return were not insulated and hung tight against the bottom of the floor joists making the addition of insulation nearly impossible. By the way, the Grundfos pump was sweat in hard, meaning no unions. What are these guys thinking?
Nothing against the plumbing firm, but I'm actually glad I'm doing my own plumbing to my own specs.

[FloridaOrange]

I guess new home buyers are not ready for the unconventional. They will spend a ton of money on custom ceramic bathrooms with multiple body shower heads, but not one dime for insulation around the hot water piping, go figure???
95% of the homes had conventional HVAC systems and low budget or middle of the road water heaters.

Water heaters and HVAC equip are on the top of the list to be "value engineered" out of a project. Owners and developers see that they can save $x per unit to switch to a cheaper unit and out they go.

I absolutely hate the term "value engineering". Usually there's little of either going on with that term.

[gpdewitt]

Back to your original discussion, I have had solar assisted electric water heating, and found it to work quite well. I would not own and electric system if it was not solar as well, they just aren't efficient. My system pumped water directly to the roof mounted solar panels when the thermostat demanded hotter water and detected that the water in the solar panels was hotter than at the thermostat. Worked well to keep the electric bill down.
As far as radiant heat, it's a great idea. I have electric radiant in my lowest floor to offset temperature differential between downstairs and 1 1/2 floors up stairs. I'm not exactly in snow country, but still I find running the floor heat helps heat the upstairs just enough to keep the central heat from needing to kick in, reducing costs there as well. True, the electricity to heat the floor costs, but PEX just wasn't an option for us.
I would think heating a basement floor would help heat your whole house a bit.
Retrofitting double pane low-e windows that don't leak makes a HUGE difference in temperature comfort. So does insulating walls as well as attic. So does sealing up every possible air leak with caulk or expanding foam. It all adds up.