Hot water heater timer update

what was the cost of the timer?
818 x.0619=$50.63
758 x.0619=$46.92
difference $3.71 / cost of timer? = pay back time.
This would be my payback time. With 2 water heaters it's a no-brainer you'd have it installed on both.

 

that's about $40 CDN, I don't know but I guess I should do it and then if they raise our rates I'll be covered for the first little while. I guess in all reallity every body should do it and we could all reap the savings from less polution and rivers damed up etc. Thanks Wolfman.

 

Wolfman,
I would think there would have to be a substantial amount of time between your weekday and weekend waking times to lose appreciably heat. Have you tried letting it just run on the week day times?
Also, I assume this is standard, but maybe not it warmer climates. Water heater jackets! If the outside of your water heater feels even slightly warm to the touch, you are losing heat for no reason. And, pipe insulation on both hot and cold for the first few feet, slows down the conductive losses.

 

I'm a custom home builder and I only use Rinnai tankless water heaters in my homes. I almost always install the heater outside on an exterior wall. When installed outside, I eliminate the cost of supplying exhaust flue, combustion air, pan and drain, and the pressure relief line. I also save at least nine square feet of usable space inside the house that would have been used for a water heater closet. These savings are then used to pay for the higher cost of the Rinnai. I reduce the air leakage associated with these closets and remove a combustion appliance from inside my living space. All of these benefits are also important parts of an overall system of building that uses standard building products and methods in new ways to achieve energy results that can't be matched. My homes air test at less than .04 air changes per hour. I supply filtered dehumidified air through a mechanical ventilation system on a timer. I circulate hot water on a timer for instant hot water during the times we commonly call for it. My 4000 sq. ft. home outside Austin TX used 1200 Kh in July and August and an additional 15 gallons of propane for hot water and cooking. We make almost no lifestyle changes to accomodate this low bill. My wife keeps it cold inside in the summer.(she would say barely tolerable but I have to sleep with a blanket) My son takes 30 minute showers. We do turn off the lights when we leave a room for the most part, but that's about it. The house takes care of the rest automatically and with the best indoor air quality that I have ever found. If I was truly green I would live in 1/4 of this size of house, but I used to and burned more energy then than now. I'm a have my cake and eat it too kind of person now I guess.

 

Check out the GFX hot water heat recovery unit - do a google search on GFX DHR. It uses the hot water going down the drain when you take a shower to preheat the cold water going to your hot water heater. I haven't installed one yet (planning to, though), but it looks like you will recover between 30% and 60% of the heat in the drainwater. Since showers are one of the largest users of hot water, the savings should be substantial. They cost in the vicinity of $300 - $400, though. Payback time might be a couple of years.

 

Tankless hot water heaters are very common in Western Europe, due to higher energy costs, but appear to be no more than a fad here.

I wish I had gone with a tankless hot water heater at my hobby farm. I put in a 40g hot water heater with a power exhaust (No chimney due to the energy efficient furnace).

In the summer, which is when I'm most likely to be at the place, my gas bill averages $14-$18. I figure that's all from heating hot water, and that's outrageous.

You waste a lot of energy with a hot water storage tank, unless you use one of those heavily insulated tanks, like this one;

http://www.weil-mclain.com/netdocs/ultraplus.htm

Before I had the new house built at the hobby farm, the old shack there had an electric hot water tank. I'd flip the breaker off unless I was using or would soon be using hot water.

A huge advantage of a tankless hot water tank is that you have ZERO standby losses when not in use. It's fully automatic too, no fiddling with timers or breakers.

http://www.tanklesswater.com/product_250SX-NG.htm

The only problem I can see is convincing folks the much higher up-front will pay down the road. If the ROI is beyond 5 years, don't expect most folks to replace a worn domestic hot water tank with anything than whatever is on sale at Home Depot.

 

Oh, I don't know about that. What's your budget?

Seriously, the wiring for a tankless is minimal. You will need a 110 outlet and a two conductor t-stat wire running from the heater to the controller.

The tankless that we prefer is the Rinnai. You can find it here:
http://www.foreverhotwater.com/index.shtml

 

The web-site isn't that great. At 140 degrees or a 70 degree rise the output is 4.7 gpm. At 50 degree rise the output is 6.0 gpm. The max output is 180,000 btuh for nat. gas and 190,000 btuh for propane. The minimum output btuh is 15,000 btuh, which is about a half gpm. If the demand is less than that, then the heater will not activate. This can be a problem in rare instances. The efficiency is 88%.

 

Ray:

I looked at the URL you provided and there didn't seem anything complicated about wiring up that control for the tankless heater. You could probably use Bell wire or leftover Cat6.

Something like widescale replacement of regular hot water storage tanks with tankless water heaters could make a big difference in overall energy consumption. Though it's hard to convince somebody to replace a leaking HWT with a unit over $800 when you can get the el cheapo at Home Depot for around $200.

 

Jayman-
Yeah, wiring it is a snap. The only reason to need to read the instructions is when you use slave controllers in other parts of the house or use multiple heaters for really large residential or commercial projects.

Selling the tankless is much easier in new construction because of the things that are eliminated by the exterior mounted unit.

 

I have an Aunt and Uncle in Santa Rosa, CA. I was always shocked at the plumbing that was left outside. Yeah, it would be nice, just wouldn't work up here.

However, if you already have an energy-efficient boiler for radiant heating, you can use the control loop to heat domestic hot water as well. Unlike regular hot water heaters, boiler domestic hot water storage tanks are very well insulated. Some only have 1/2 F per hour heat migration.

I'm surprised a lot more folks here don't put in energy efficient gas furnaces that are side vented with plastic piping. They get a "regular" furnace but need a chimney installed. They always forget to factor the cost of the chimney ... so it's a wash as far as installed cost, and the energy efficient furnace should save 20-30% minimum in heating costs.

 

Sorry Wolfy, didn't realize your home was and will be all electric. That really changes everything.

First of all, like you said an electric tankless heater does exist, but they need something like 150 amp service minimum. So let's see you're going to have to pay for a 250-300 amp service, heavy 000 wire ... forget it.

Have you considered a geothermal heat pump? If they are properly installed - I know a BIG "if" - they are remarkably efficient for heating and cooling.

Here in Manitoba, Manitoba Hydro is really pushing their use and is offering incentives too. I was all set to go for a geothermal solution when the few folks I spoke to had less then glowing reports.

I think a lot of that has to do with how deep the heat transfer loop is buried. Ideally, the deeper the better. Most installers put them 4 ft down. Around here, the frost level can hit 4ft, so even though the heat pump will work, it experiences a rapid drop in efficiency and on colder -40 nights the supplemental electric resistance heat will kick in.

In hindsight, I could have rented a backhoe and dug the d*** trench myself for the heat transfer loop. The soil here has good drainage, I could have gone down 15 ft if I was so inclined. Another regret in my life.

With a heat pump, you can use a de-superheater to heat your domestic hot water, which is then stored in a insulated tank like usual. This only works when the heat pump is in cooling mode, I think in your climate that would be most of the time.

You can also do a deep vertical loop, but that costs a lot more money. Any chance of rebates from your local Utility??

Otherwise, it looks like your plan for the HWT timer and insulating blanket will have to do. Just curious, will you be using electric baseboard heat? Or an electric resistance element in the attic-mounted system fan?

 

Wolfman- Is there any possibility of a small (100 gallon) propane tank on the site of the new house?

Jayman- You know from whence you speak. The Rinnai is only freeze protected down to -30 f. so in you climate you would want it inside I guess.

There are indeed, a few problems with geothermal. Cost is a big roadblock and if everyone in the neighborhood jumps on the bandwagon in a hot climate, you will slowly heat up the groundwater and reduce your efficiency. Poor istallation leads to frustration and system abandonment, oh and lawsuits.