Hi Effeciency Water Heater

Constantin

.... and I'm with Larry. Most gas water heaters have a much lower input/output capacity than any home heating system can provide, when it is properly set up. I like the inherent simplicity of an indirect over an active system, removing the huge standby losses of gas/oil systems while maintaining the superior recovery over electric systems. In an ideal world, you'd pair a low-mass, condensing, modulating boiler with an indirect, but in the real world, only natural or LP gas will allow you to do that.

Another thing to consider is getting a GFX Heat Exchanger to recover much of the heat leaving your house via the wastewater. It preheats the incoming water with the water coming down the sanitation drain, so that your indirect or direct water heater have less work to do... and a 50 gallon indirect with a GFX may suffice where your current 50 gallon direct water heater does not...

saul deutsch

Hi Effeciency Water Heater

I have a one family home with a 2 year old Slant Fin boiler(SA 70) - 50,000 BTU. I believe it is sized correctly for the heat loss. There are 7 members in the household, with a large demand for hot water. I would be interested in knowing if anyone can suggest to me what to consider purchasing for my next hot water heater?
I am looking for a highly effecient unit. I don't think I can use an Indirect unit due to a lack of excess capacity on my boiler. I also would like a water heater that has a long life and safe with respect to carbon monoxide emissions. I would appreciate if someone can provide some ideas or suggestions and a ballpark figure for the cost of the unit and installation.

On another matter, is a solar water heater something to consider? If so any particular companies to consider? What are some of the advantages and disadvantges? What is the payback period on the solar units? Are the units reliable? What is the cost to install such a unit?

Thanks.

Tundra

I wouldn't be so fast to discount an indirect. Only in the coldest part of the year will your heat demand approach the output of your boiler. Even so most boilers have a little extra output. If an indirect is placed on a priority zone it tis not necessary to factor it in to the heat load calculation. If you put an indirect on a priority zone your home will not notice the twenty minutes it takes to rewarm the indirect.

Gene_3

agreed

Indirects are the most efficient, by wiring it for Priority you will commit the boiler to only making h/w and not heat, this usually only lasts 10 minutes and you will not notice the delay in heat, you will notice a lack of hot water.

Larry (from OSHA)

some questions

Saul,

I am a homeowner like yourself with a little experience with indirects. First of all what do you have now and how inadequate is it? What type of usage does it get now? ie. long showers, hot tub, consecutive showers, and like that? I had a 65 gallon indirect with fair recovery that never ran out of hot water. I just replaced it with a 50 gallon unit with slightly better recovery and included a tempering valve (which all installations should have) and store 140 degree water and send 118 degree water to the faucets. I have yet to run out of hot water with this setup. Also the output of your boiler may not be such a big deal. The heat exchanger in the indirect may only be able to transfer 50,000 btu's/h anyway. Depends on the brand you get. Your recovery may be a little longer, but that is my guess only. As far as efficiency, an indirect is a very good choice. Give a little more information and I am sure that some of the professionals here will be able to help you out.

Happy Heating.

Larry (from OSHA)

Ted Robinson

Use a steam boiler for an indirect hot water heater?

Myabe this is not such a foolish question. (When I was a kid we had a separate hot water storage tank on a stem boiler.)
Is the efficiency an improvement over a gas fired hot water heater?

saul deutsch

My current hot water heater is a AO Smith 1996 model 50 gal. I dont always have enough hot water. The question is what size indirect to go with and will I have problems with my boiler during a cold winter day maintaining my temp at 70 degrees? My boiler is basically sized correctly for the heat loss of the house.

Bill de Jong

An indirect water heater is a good idea with the use of a priority control as has been suggested. The other alternative to consider is "Tankless" water heaters. Properly sized these units can give you water 24/7 if desired and are more efficient than standard boilers. Check websites for Takagi, Rinnai, Bosch, to name a few.

Larry (from OSHA)

it depends

Hi Saul,

Some things to think about and discuss with a knowlegable heating contractor. (perhaps someone here on the Wall or from the find a professional link above) A fifty gallon indirect may be big enough with a tempering valve. (Store it hotter and mix it down for use) Indirects have typically quicker recovery. Maybe a bigger tank is in your future. Really depends on how you use your hot water. As far as keeping the house warm while the tank is recovering, if the tank is run on a priority basis, the 20 or so minutes to recover should not affect the comfort in your home. This also depends on the overall condition of the insulation, etc. of the house.

Keep researching and you will find a good solution.

Larry (from OSHA)

Steve Ebels_3

On a couple occasions

When we encountered your problem we left the existing hot water heater in place and installed a small Takagi (TK-JR) in front of it. This in effect preheats the water going into your existing tank which is then able to keep up nearly endlessly. The Takagi's are all in the 80%+ range for efficiency and we have virtually no trouble with them.

PS: they only come as gas fired units.

Dirk Wright

I really like my Toyotomi tankless water heater. I have the OM-148, which uses home heating oil. They also make a model that runs on kerosene. The water heater output is 150,000 btu/hr, has a stainless steel heat exchanger and advanced controls. The only down side is cost, which is currently about 1400$. The parts, though rarely needed, are expensive also, but it takes a standard nozzle, which are cheap. Pump pressure is 192 psi, ignitor is 17 KV, and efficiency is about 88%.

JackFre

www.rinnai.us

.87 energy factor. At 70*F (50-120) rise it will produce 4.5gpm all day long. When no water is being used, no energy is consumed. Compact, Direct Vent sealed combustion. You will need to carefully examine your gas line sizing to delvier 180,000 btu. The burner will modulate (fire) from as low as 15,000 up to the 180k depending upon demand. Low flow...low fire, high flow...high fire. many utilities are offering rebates with the installation of the Rinnai and strating Jan 1, '06 a $300 federal tax credit will be available for the installation of the Rinnai Continuum.

Scott Gregg

www.Noritzamerica.com

I too am a big fan of tankless. Noritz is my first choice. An N-063S gives up to 370 gallons per hour! I have found them to easily run 3 showers, year-round in VA with all incomming water temperatures. Their larger units can give you even more.

Yes, they cost more up front, but that's what high-end appliances do; they are better and cost more.

saul deutsch

Hi Effeciency Water Heater

I don't know whether the information being given to me is correct. My boiler is a 50,000 btu output (Slant Fin SE70 model-gas). My house heat loss cal. is 48,000. There are 2 adults and 5 children. I am being told that I may have a problem with a 60,000 gal. Indirect Water Heater. The house during winter time especially on a real cold day may not be able to handle both. The temperature may start to drop since a total replenishing of the water tank may take 60-90 minutes. Coupled with a call for increased heat in the morning hours to bring up the temp. from the night setting I may only be looking for trouble. I would like to know if this analysis is correct. If yes, is there any way around it (short of replacing the boiler with an excess capacity) so that I can still install an indirect system. If I can't use the indirect, what other systems are out there? I wan't something that is long lasting, reliable and energy efficient. Please list particular names and models.

Thanks.

Larry (from OSHA)

how to choose

Hi Saul,

Confusing, isn't it? I can understand your concerns, and for answers to be helpful, I believe you need to take a good look at how you use your hot water. If you have a 60 gallon tank sitting at 140* and take 118* water out of it using a tempering valve, your usable capacity is more like that of an 80 gallon tank or so. Also, consider that while you are drawing down the tank, it is starting to recover at the same time, so it is not an all or nothing type of deal. A five minute shower would use about 10 gallons or so (I think).

As far as the boiler not keeping up with heating the house, this is certainly a valid concern, but, easily dealt with. A simple delay timer can be wired in to interupt the tank recovery and allow the house heat to come back on in 20 or 30 minutes to prevent the house from cooling down too much.

In my own experience with this I have never had a problem with the house cooling down too much. It gets to -20 around here. I do not have a delay timer relay installed. Does your home have decent insulation?

This link is some info on the mixing valve that I have:

http://customer.honeywell.com/Techlit/Pdf/50-0000s/50-9141.pdf

If after all of this, you still do not have a good comfort level to get an indirect, any tank maker like Bradford White or A.O. Smith or whomever, has high performance water heaters that would work. You just lose the efficiency of a single heating appliance. I hope my input as another homeowner is at least a little helpful for you.

Larry (from OSHA)

Dirk Wright

tankless gas?

Ever consider a tankless gas water heater? One advantage over tanks that very few talk about is that the hot water from a tankless HWH is clean. The hot water in a tank gets nasty and full of bacteria after sitting so long. While I didn't specifically test it, I did feel that the hot water was cleaner after switching to a tankless oil fired unit. Hope this helps.