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SylvanLMP.
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MasterPlumbers
Working with my general/plumbing contractor. Looking for advice on tankless hot water systems, both gas and electric. Specifically;
1. Are they as efficient as advertised?
2. Would they be cost effective in my region (southeastern VA – Norfolk)?
3. Advantages of gas over electric or vise/versa.
4. Installation concerns.
5. ANY OTHER ADVICE ANYONE CAN PROVIDE.
We have a very old (85 yrs) home w/ a poorly designed hot water supply system (heater is in a separate garage 80′ away). No room in house for a traditional heater. Tired of waiting 5 mins for hot water!
Thanks in advance for any help.
Please reply here, or directly to my e-mail: [email protected]
Tim -
QUOTE]Originally posted by TIDETIM:
Working with my general/plumbing contractor. Looking for advice on tankless hot water systems, both gas and electric. Specifically;Question 1. Are they as efficient as advertised?
Answer. Depends on applications and manufacturer
Question 2. Would they be cost effective in my region (southeastern VA – Norfolk)?
Answer. Contact your local utility as per therm cost GAS/Electric
Question 3. Advantages of gas over electric or vise/versa.
Answer. Gas needs venting
Electric doesn’t
Gas fired hot water tanks need piping toway and RETURN and gas lines and flue PLUS stand by losses
Gas fired hot water tank need a circulator UNLESS you use Nibco JUST RIGHT that is non electric device for circulation
Question. Installation concerns.
Well a major concern is the use of apprentices inside a structure not being watched VERY carefully
Having a non qualified plumber dabbling in heating and or gas work
Use of cheap non quality materials and not having the job inspected
5. ANY OTHER ADVICE ANYONE CAN PROVIDE.
We have a very old (85 yrs) home w/ a poorly designed hot water supply system (heater is in a separate garage 80′ away). No room in house for a traditional heater. Tired of waiting 5 mins for hot water!WOW
WHAT a WASTE of WATER waiting HUH? PLUS your paying for this heated water TWICE .. Pay to heat it let it cool THEN pay to heat it again.
Thanks in advance for any help.
Please reply here, or directly to my e-mail: [email protected]
Tim[/QUOTE]
Point of use hot water electric heaters normally do not allow for high volume use just for possibly a basin
Gas fired coils do offer lots of water BUT are bad for short volume usage.
Everything has a trade off.
Depending on the amount of people living here and the type of fixtures like dish washers or washing machines etc.
One thing electric wiring has no stand by losses and wont explode in case an inept helper does something wrong.
The NEC is a decent code with all kinds of protection devices.
The NEC takes developed lenth and amperage into consideration along with the circular mill of the wire and even ambient temperature.
Most electric installers have one thing over some of the stumble bums dabblers in plumbing.
Whether it be residencial Or commerical work the average electrican will do the same PROFESSIONAL JOB.
I wish I could say the same with plumbing.
As a stationary engineer I know the NEC was constantly upgraded with the NFPA.
Most of the stumble bums I read posting may have taken a really simple test and never bothered to open a book ever sinse.
With more electrical lines less chance of floods as less pipng is required.
Most electricans have the common deciency to put a diagram or a box with each switch/breaker labeled.
With stumble bum OJT plumbers your lucky to get a valve that works as most plumbing material today is made on another planet let alone another country.
Even the NFPA has lots of new code changes for the NEC but not that drastic change in NFPA 13 fire protection rules.
If electric prices are in line with gas I would personally go with Electric CLEAN safe and PLUMBING FREE drips during the dog days of summer when huminity can cause mildew on piping.
Hey IM only a Master plumber so I could be wrong LOL
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http://www.builderswebsource.com/techbriefs/tankless.htm
If your hot water use is for showers and tubs of water, and you heat your tea and small amounts in a pot, and you will have factory representatives in to completely clean and repair your instantaneous heater every year as done in Europe or Japan, the unit should suit your needs.
An instantaneous gas heater uses the same blowtorch to heat a cup of water as it does your shower water, so you will have a water heater that has a gas flame that is large enough to heat your house. Most have difficulty heating less than a 1/2 gallon per minute flow rate of hot water, so they tend to waver in temperature at that slow rate, though they become steady at greater flow rates.
Your old water heater lasted many years, so the water is not hard; this is important, because many instant water heaters use small tubes that can lime up and burn out in hard water areas.
Otherwise they do save money by not losing heat as does a 40-gallon vessel sitting all day throwing heat away. As the gas bill for heating water for a family is about $240 per year, you could save about $60 per year, This would amortise a $1000 installation in about 16 years.
http://www.tankless-water-heater.com/
http://www.korient.com/16Elecwat/Elecwat.htm
http://www.termotronic.com/termoi/
http://www.plumbingproducts.com/eemaxso.html1. While the shower has its own source, what does one do about the other fixtures? Do they each have their own point-of-use heaters? Are they by supplied by a central water heater – if so, why bother with the point-of-use unit other than to have one supply tube going to it?
Unless the electricity is produced by a dam or atomic energy, the electricity is produced by burning a fuel. the line losses transmitting the electricity are high; so most electric rates are 3 times the cost of providing the heating by burning fuels in the home. Cutting the electric bill in half by making the electric usage more efficient still makes electricity more expensive.
The typical family bill for gas or oil hot water is $250 per year. The typical electric bill for the same hot water use is $800 per year. Cutting the electric bill in half still makes it $150 per year more expensive – and the cost of installation of the point-of-use electric heater is very high.
These are reasons central, fuel-fired water heaters are still preferred in the majority. Only one, long-lasting appliance required. When an instantaneous unit is used for the whole house, the small tubes lime up in many areas and a small flow from only one tap of less than 1/2 gpm makes the unit hunt. A point-of-use heater at a sink for coffee or a small sinkful does make sense, small quantities make for small bills. Showers and washers make for large bills.
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quote:
Originally posted by Harold hydronic.net:
http://www.builderswebsource.com/techbriefs/tankless.htmIf your hot water use is for showers and tubs of water, and you heat your tea and small amounts in a pot,
Answer. Harold, are you aware of the dangers of using water from a hot water tank for domestic drinking?
Unlike instant hot devices that are safe for potable use like coffee tea etc.
The “instant hot” water discharge can be adjusted to 190 degrees.A hot water tank UNLESS commerical normally is set between 125-140 Deg F.
Harold says
and you will have factory representatives in to completely clean and repair your Instantaneous heater every year as done in Europe or Japan.Answer: Harold Americans are lazy and thus a lot of bums install a hot water tank and never look back for the code REQUIRED testing of safety and relief devices.
Most of the Fraud plumbing and heating folks have no clue to codes when it comes to unfired and fired pressure vessels.
INSTALL AND FORGET is the name of that Billy Butt Crack gameHarold says An instantaneous gas heater uses the same blowtorch to heat a cup of water as it does your shower water, so you will have a water heater that has a gas flame that is large enough to heat your house.
Answer. True BUT suppose this person uses a point of use 21/2 – 4
gallon electric heater for a wash basin, this will provide enough for the average house hold of four.Think how much water you actully use brushing your teeth.
Most folks in this country turn the water on and let it run wasting thousands of gallons a year
Harold says.
Most have difficulty heating less than a 1/2 gallon per minute flow rate of hot water, so they tend to waver in temperature at that slow rate, though they become steady at greater flow rates.Answer.TRUE But if you only use this ON DEMAND blow torch burners
for lager volume usage like washing machines/bathtubs and dishwashers where is the problem?NO STAND BY LOSSES
Harold says.
Your old water heater lasted many years, so the water is not hard; this is important, because many instant water heaters use small tubes that can lime up and burn out in hard water areas.Answer. Yes the water quality seems good so this is IDEAL for point of use applications.
Another great thing about point of use is if one tank should fail they still have H/W for other applications
Harold again.
Otherwise they do save money by not losing heat as does a 40-gallon vessel sitting all day throwing heat away. As the gas bill for heating water for a family is about $240 per year, you could save about $60 per year, This would amortise a $1000 installation in about 16 years.Answer.
Debatable as having an older tank has loss of efficency as build up occurs on the bottom of these tanksHarold says.
1. While the shower has its own source, what does one do about the other fixtures? Do they each have their own point-of-use heaters?Answer. Depends on the developed lenth and a lot of point H/W heaters can fit under a vanity so just having hot water for small volume usage saves money and stand by losses
Harold again.
Are they by supplied by a central water heater – if so, why bother with the point-of-use unit other than to have one supply tube going to it?Answer. To save piping as only ONE cold water line is needed for
point of use devices and less piping means less chance for leaksHey it is intreasting HUH Harold all the pros and cons>?????
Harold says.
Unless the electricity is produced by a dam or atomic energy, the electricity is produced by burning a fuel. the line losses transmitting the electricity are high;Answer. So are plumbing friction losses and heat loss and circulators to make the H/W return work more efficiently
Harold says.
so most electric rates are 3 times the cost of providing the heating by burning fuels in the home. Cutting the electric bill in half by making the electric usage more efficient still makes electricity more expensive.Answer.I must agree Unless your worried about the impact on the environment with all these gas fired things burning with no one checking to see how toxic the fumes are. Think of all the deaths even today because of CO due to improper combustion NOT so with electricity
Harold this is fun LOL BUT I must go..
The typical family bill for gas or oil hot water is $250 per year. The typical electric bill for the same hot water use is $800 per year. Cutting the electric bill in half still makes it $150 per year more expensive – and the cost of installation of the point-of-use electric heater is very high.
These are reasons central, fuel-fired water heaters are still preferred in the majority. Only one, long-lasting appliance required. When an instantaneous unit is used for the whole house, the small tubes lime up in many areas and a small flow from only one tap of less than 1/2 gpm makes the unit hunt. A point-of-use heater at a sink for coffee or a small sinkful does make sense, small quantities make for small bills. Showers and washers make for large bills.
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Harold and Sylvan, you guys are great.
Harold I met you once at seminar you gave at IBR training, especially the EDR and other great information relating to hydronics
Sylvan if your were not so sarcastic, you would be perfect, good thing Harold is the straight man.
I can honestly sense your frustration with the incompetent advice others give on here but being so sarcastic makes you look like the bad guy.
As a professional engineer specializing in plumbing and fire suppression systems I totally agree with your evaluations and diagnosis and yes I also agree Wallford plumbing and heating is not plumber but someone just trying to survive with limited training
Sylvan in all honesty you are not going to educate the world but you did give it a great shot.
I thoroughly enjoyed your approach on the article two views on water supply piping on plumbviews section of this site and I also could not agree about redundancy with regard to sewerage disposal systems.
Your only going to stress yourself out so just ignore these SB’s as you call them.
John Hastings PE. Washington State
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The efficiency is soemtimes overhyped, but your situation is one of the few where a tankless heater is justified. Namely, a small available space in the area where the water is going to be used. The cost factor is the same whether you use a tank or tankless, namely the local energy rates. The only way that a tankless heater can perform is to either reduce the flow past the heat source to the level it can raise the temperature or raise the energy input to match the flow. Most do a combination. They put flow restrictors to limit the gpm factor and also use high energy inputs to do the actual heating. With gas, this requires a large flue exhaust pipe, and occasionally a larger gas line. Electric heaters require very large wires and circuit breakers to perform their heating. If the house wiring cannot accomodate the maximum amperage required, then the gpm through the heater has to be reduced accordingly. This can lead to pressure imbalances in the water system if there are several hot water demands at the same time. Scaling will occur faster in an electric heater since all the heating is taking place on the element. A gas heater will be partially self cleaning since the heat/cool cycles expand and contract the copper coils and have a tendency to flake off the build up in the coils. Gas would be the best choice if its cost is comparable or less than electricity in your area, and you can install a flue and gas line to the proposed heater location. Otherwise, electric wires are easier to install if the house distribution panel can handle it.
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John, in all honesty YOUR the only Engineer I agree with 1 million percent LOL
Thank you so much for your kind words.
When I started plumbing as an apprentice I knew my heating like most plumbers was lacking.
Thankfully I had the brains to know this and not put the words plumbing and HEATING behind my business name until I actually felt comfortable doing all aspects of heating.
To many frauds are saying plumbing and heating without ever knowing there are codes.
I asked one “HTG” guy several basic questions and he comes back with off the wall quoting a code he has no clue is rock bottom.
Look at 4th year over 19 YEARS and still stuck in his grade BUT thankfully he knows not everyone can be certified as a journeyman and the trades do needs helpers.
When I was 17 before president Johnson said no 17 year old allowed in a war zone I remember this seaman E-3 with over 30 YEARS in SERVICE with gold stripes.
Here I am a 17 year old kid also an E-3 and looking to move up.
Thankfully 4th year knows his limitations NOT A PUT DOWN but the truth.
Its the screw ups who THINK they are plumbers and heating guys that scare me.
If these folks are in this profession why not try to learn all they can?
I AM STILL learning every single day something new with in these trades.
For example I have a Masters Fire suppression piping contractors license and have the stand pipe code and the NFPA 13 and even studied the NEC BUT I find I am now specializing more and more into plumbing and not as much into sprinkler except yearly residential testing.
Heating if taken seriously is still a challenging field but the caliper of the so called HTG contractors needs a lot to be desired.
What I enjoyed was having an old mentor in heating always trying to out do his last job constantly seeking to make the next job better.
Thank you John PE so much again … Sylvan
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Good to see you are still prospering there, John. Many of the words I used to say are now on the http://www.hydronic.net site. I just reached the number of visitors on the site that equals the number of attendees of the IBR Schools over a 12 year period; it should more than double next year. The learning goes on.
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50 years not 19, and since I own the company, they cannot fire me.
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quote:
Originally posted by fourth year:
50 years not 19, and since I own the company, they cannot fire me.
50 years dont you think it is about time you learned something about this trade?
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