Sudhir was visiting his childhood friend Tanmay. They did their schooling together. Sudhir however opted to be a Financial Consultant and got a job from IT Major in Pune whereas Tanmay opted for Mechanical engineering and got placed with Automotive firm Delhi. During interaction Sudhir found out that Tanmay is soon going for renovation of his parental house in Delhi. Since Sudhir too was planning to construct a house on the outskirts of Pune so their discussion was ranging from topic of stone finishes, furniture plan, what wardrobe to order, which aircon to purchase. However when it came to selection of water heater Sudhir Complained, “There aren’t any experts available on this subject and if they do exist i wonder where they are, local plumbers are without any knowledge about the recent advancement in hot water technology. The Retailer or shopkeeper would advise only those products that he has stock of but which may not the be the right choice. If you call Manufacturer then they are only promoting technologies they manufacture, so it is creating lot of confusion.” However Tanmay had some knowledge before hand, “I did search for some information on google, although that information has lot to do with western and pacific countries, nevertheless this is what I know now,
- A) Electrical Water Heating is Most Efficient.
- B) Gas Water Heating is more economical in day to day running.
- C) Solar is good option if there is ample of radiations/sunlight available in your area.
- D) Heat pump works best in tropical climate zones and for the application which involves radiant heating and pool heating.
- E) Geothermal Heat Pumps are the all rounder for energy efficiency and works beautifully well in most of the regions and climates, however it pretty expensive technology to implement.
- F) Other Alternative technologies are still in nascent stage and yet to prove their long term worth and after sales serviceability.
“So you are yourself an expert in this field now”, remarked Sudhir. “Yes, at-least better than my local plumber, but still don’t know what to decide and how to decide.” quipped Tanmay.
It was already late noon and both of them were so engrossed in the discussion that they almost forgot that most of the restaurants have stopped taking orders for the lunch by now. Although it doesn’t happen so often, but Sudhir family was away for a week long marriage function of Tanmay’s cousin in Jaipur. He was also supposed to attend the function and went to Jaipur along with his family but returned just a night before on learning that Sudhir is coming. As marriage was still good three days away so Tanmay didn’t wanted to waste the opportunity on catching up with Sudhir almost after 3 years.
“Let’s try out that Santa Banta guy” suggested Sudhir. “U still remember that guy?” asked surprised Tanmay. “Well, if you are away from Chole Kulche for so long, how could u forget him. Plus do you remember how we use to spend after school hours at this guy place with no money in pocket, but still managed to feast on his delicacies by telling him all sort of stories & once even managed to convince him that your father is in US and he can export his chole kulche’s via him and earn heaps of money”. Chuckled Sudhir. Hearing this both a hearty laugh afterwards.
The settings were more or less same at Santa Banta what it used to be 10 years ago, except that the place doesn’t carry same level of resemblance any more. Old Stained water glasses have given way to “Bisleri” bottles, tissue papers are standard with every “Thali” now. “Achar” has become frugal in servings and has been replaced with packaged one rather than home made. But one thing remained same, the relishing taste of Chole Kulche.
Suddenly Tanmay got a tap on his shoulder. He turned to his back and noticed a familiar face. “Ranjan, what a pleasant surprise”. Hearing this even Sudhir turned looked towards him and recalled the Student who spent almost half of his school life standing outside the class. But surprisingly he always use to score good marks in all his final exams. “What are you doing nowadays man”. “I am an environmental engineer” answered Ranjan to Sudhir question. Both of them still not able to believe what they have just heard, but wondered that destiny can take man anywhere.
“Well I know its strange for you people to believe but that is what is my passion now a days” Said Ranjan seeing the look on their face. Embarrassed a bit Tanmay tried to change the topic and they started talking about their school days. Tanmay asked Ranjan to join them at his house to which he readily agreed after making call to his house that he would be late and they should not wait for him over dinner. The talks progressed on to their professional lives. During which both of them learnt that Ranjan is in midst of preparing a feasibility study for a small town in uttarakhand who wish to harness the waste heat from nearby paper mills to heat up their rooms as well as providing them hot water. “Wish that we could have also made so easy choices for house” sighed Sudhir.
“Your choices are as difficult or as easy as you wish it to be”. “What?” said Sudhir. Ranjan words left them speechless for a moment! “OK, lets sort out what are the issues that you are facing” asked Ranjan. Both of them shared discussion that they had in the morning. “OK, so let me try to answer your queries one by one”.
“Tanmay what do you think your hot water demand is going to be?” asked Ranjan. “I am having 6 bathrooms in total, of which I am planning to put rain showers in three and bathtub in children bathroom. and Normal one in my parents and guest bathroom”.
“So your demand is 30 Liters Per Person Per Day for Normal Shower, 40 Liters Per Person Per Day for Rain shower and lets say your children use bathtub on holidays then it would be 100 Liters for your 200 Liter bathtub, since you never fill up to the brim, cause then water will spill out the moment someone steps in it.”
“Are you sure that Rain Shower would only consume 40 Liters, the company people told me that the Rain shower has flow rate of 50 Liters per min.” Asked Tanmay.
“Well, that’s design capacity, which means something like ur car mileage, company may claim something but on real terms it may not be so. The high flow rate that companies market is while taking into account high pressure of water, which is 4-5 Bar…..”
“And human body normally can’t withstand a pressure of more than 2 bar” interrupted Tanmay with delight on his face, after all so much of hours spent on google has resulted in increased level of knowledge in him.
“Right, plus there are other factors as well. A rain shower mixes air with water, and it also gives you more comfort factor and more water flows while taking shower. So the time spent in shower also decreases drastically. So if you are spending lets say may be 5-6 min in normal shower then you may spend only 2-3 min in rain shower. which overall reduces your water consumption. Which brings us towards the calculation part. But before doing that I would like to ask a question, are you going for centralized hot water system or going to install at point of usage.” Said Ranjan.
“I just don’t know, what would you suggest” Replied Tanmay to Ranjan’s query.
“It depends on some basic questions. Do you want 24 hours running hot water?” asked Ranjan.
“Well yes, My parents would like to have that available through the day, and during night time in winters when my kids goes for nature’s call they don’t even wash their hands out of the fear of chilly cold water, you know how dreadful Delhi winters are”
“In that case go for centralized water heater with re circulation line, it will provide you the desired comfort…….” “what is a re circulation line?” asked Sudhir who otherwise was a mute spectator to the entire proceedings.
“U must have noticed, that while you open up the hot water tap, it takes a while before cold water gets replaced by hot water. It’s because the hot water in your pipeline has lost its heat due to the low ambient temperature. Normally we insulate our pipes but that helps us out in reducing the temperature drop, it will also keeps line warm to an extend but would not prevent water from getting cold due to long period of non – usage. In order to prevent this from happening you install of recirculation line, which is an additional line connecting the very last point of hot water pipeline in your house and recirculating it back with help of extremely small pump, which consumes even less electricity than your bulb. So what it does is that it keeps the hot water running in the pipeline just enough so that your water is always warm in your pipes.”
“Which brings us back to the calculation part” continued Ranjan. “ So your family consist of 6 people now, your parents and your two kids which means, 30 Liters X 2 Person, 40 Liters X 4 People and 100 Liters for your bathtub and 30 Liters X 2 for guest room, which brings us out to 380 Liters. Now this water would not be consumed at once, in morning you might 2 hours to consume this water and your kids for sure won’t be using bath tub in morning hours on weekdays, which means that you would have sufficient recovery time for them whenever they wish to use it on holidays or weekends. Which means that your actual usage peak usage might be 380 Liter for morning 2 hours, which roughly translates to 170 Liter Per Hour. Now what kind of heaters are you going for?”
“To be honest I am confused what should i go for?” Replied Tanmay. “Which means you have choice of abundance and that’s the reason why you are confused.” Said Ranjan.
(Meanwhile Listening all this Sudhir was wondering if Ranjan was more of engineer of philosophical gyaan rendering guru or what. But what ever he was saying was making sense so far.)
“Let me make it easier for you. First question: Instant or Storage Type.” continued Ranjan
Tanmay: Well Why should i go for Instant?
R: If you have paucity of space
T: I have ample space available on terrace.
Sensing that this is the right time for him to clarify his doubts as well Sudhir also jumped in the fray.
“Although i have terrace but I don’t wish to spoil my space for other things, So does it means that instant is the only option for me?”
R: Not necessarily, do you have high flow shower fixtures like Tanmay.?
R: Do you have ceiling height available to put in your water heater?
R: Are you OK with the idea of Water Heater been placed on your wall, it might play contrary to your aesthetics, although nowadays we do have color options available?
S: Well aesthetics is not an issue with me, but personally i don’t like anything bulky protruding from the wall.
R: Then either you can go for instant or centralized water heaters and Tanmay i would suggest you to go for centralized water heater of 300 Liter Capacity.
T: But didn’t you calculated the capacity as 170 Liter, and why not instant for me?
R: Lets say u wish to draw out entire hot water at one go, then maximum you may be able to withdraw is in the range of 60% to 80%, because the moment you will start drawing hot water, cold water will start mixing in it and thus reducing your hot water temperature. So we need certain amount of buffer to overcome that dropping of hot water temperature. I also didn’t recommended instant for you cause in that case the energy input required would be very high. Lets say u wish to go for electrical instant, then in order to meet your kind of demand, in which there is quite high possibility that two rain showers may operate simultaneously then you may need approx 30 Liters Per Minute of flow, which if i translate to energy input in terms of KW may turn out to be 80KW, which is highly impractical.
S: Then why instant may work for me?
R: Cause Pune doesn’t have that severe a winter that Delhi has so you may not have to heat up hot water on a similar scale as of Delhi. Since you also mentioned that you don’t have any rain shower, so let me to conclude that your demand of Hot water in terms of Liter Per Min would also be not that high. So a instant water heater available off the shelf in market may be sufficient for your needs.
T: Ok, the capacities are worked out, now what about heating mode, what should i opt for, Solar, Electrical, Gas or any other alternate technology?
R: First a little bit of fact re Solar. As you are already aware of that Solar energy is literally free of cost. However it is not an instant source of energy you can’t heat up your water instantaneously. It takes bit of time to harness this energy and there would be certain days when solar would be missing altogether. For those days you need a backup. So if you have piped gas available in your area then you may go for Solar with gas backup, as piped gas is cheapest so far as running costs are concerned. If gas is not available then you can go for Solar with electrical backup. However you should keep one thing in your mind that your solar would not yield positive result if you under size or oversize your system even by one step! So in case of Solar, the calculation of hot water demand per hour would get replaced by hot water demand in Liters Per Day as this is the time required for Solar water heater to heat up the entire content of water. In your case i would recommend 450 Liters capacity of Solar water heater. 380 Liters is your actual demand, minus 60 Liters required for guest room, as it would not be occupied regularly which comes out to be 320 Liters. Balance 130 Liters is your cushion.
T: What if i would opt for Gas Only?
R: Even that is nice option, there is nothing negative in Gas Water Heaters, they are much more faster in hot water recovery, is cheaper in running, and much more environmentally friendly as well. Its just that in Solar you are not burning any fossil fuel, so not only you are further reducing the overall impact on environment and you would also be saving on your energy consumption bills as well. The only precaution as i explained earlier is that sizing should be proper so that you are in position to recover your investment over it.
S: In how much time do you think that Solar is able to recover its investment?
R: There is no fixed formula to calculate it, however what i can comment is that in gas fired water heater it costs almost 24 to 30 Paise to produce 1 liter of hot water, in electrical water heater you may consume approx 55-65 paise for 1 liter. Solar is free, but there is investment cost which need to be taken care of. You are yourself a financial guy, you can calculate that yourself, can’t you?
S: Well you are right, but then it depends on usage as well, the higher the usage, more the recovery.
R: Yes and No. No, because then in higher usage you might have to increase the capacity of the Solar Water Heater as well, in other words higher investment. Yes, because that incremental investment would be lesser and lesser for per 50 Liter of Solar hot water capacity.
T: What about Heat Pump?
R: Heat Pump is even more energy friendly than Solar, however the issue according to me is more of maintenance. There aren’t many technicians available for this technology. Although the manufacturers say that even a normal air-conditioning guy can also repair, but for me that doesn’t sounds logical. The reason being is that air-conditioning technician knows in and out of summer cooling, but he doesn’t know anything about hot water system and its functioning, he may repair the heat pump, but he can’t understand the hot water system as a whole, so lets say you call him up and say that I am not getting sufficient amount of hot water in my bathroom. He might reply that Heat Pump is working, but he has no idea why you are not getting hot water!
S: Well Ranjan, I think that now i know what i have to do with my house, first of all i would choose my fixtures and then would decide on the hot water system.
R: That’s the right method.
T: Ranjan, Its such a simplistic topic, and yet there is acute dearth of professionals in this industry (Hot Water), how come you are having such in depth knowledge?
R: Its because of my current project that I am doing for my clients for hot water generation from waste heat. The first thing that we do with any such project is to talk to grass root level people, which in this case of plumbers and water heater technician. They provide me practical knowledge, whereas google provides me basic theory of knowledge. So putting both the things together have actually helped me out.
“It happens so rarely that the work we do also carries satisfaction of doing something good for the society, you must be so lucky” remarked Sudhir.
“Well i didn’t planned my career but i did followed my heart and my gut feeling was the one which ultimately landed me up in such a position.” said Ranjan.
“What about dinner?” both Ranjan and Sudhir spoke at almost same time.
“Its time for celebration, after all we are meeting after such a long time, so lets have wine tasting session first then rest of the things would be decided later on” said Tanmay with glee in his eye.
“Great, although the last time i had wine, i almost spoilt my shirt with all those swirling and smelling” said Ranjan. “Well then you arrived at the right place at the wine expert house” Tanmay told with hint of pride in those words and the evening continued to blossom…
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