If you are planning to construct a new house or going for renovation then selection of water heater is always a cumbersome process. “There aren’t any experts available on this subject and if they do exist then 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 be the right choice. If you call Manufacturer then they are only promoting technologies they manufacture, so it is creating lot of confusion.
Given below is the search and research for some information on google:
- 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 is 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”, at-least better than the local plumber
“Your choices are as difficult or as easy as you wish it to be”
Let’s have some deep discussion on it:
“If you are having 6 bathrooms in total, of which you are planning to put rain showers in three and bathtub in children bathroom and Normal one in 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 let’s 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.”
“It depends on the design capacity, which is something like your 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”
“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 let’s 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 planning for centralized hot water system or planning to install at point of usage.”
“Well it depends on some basic questions. Do you want 24 hours running hot water?”
If Yes then
“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?” “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 re-circulating 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.”)
“Let’s come back to the calculation part”. So if 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?”
“Still confused what should i go for?”.
“It means you have choice of abundance and that’s the reason why you are confused.”
“Let me make it easier for you. First question: Instant or Storage Type.”
Now you will ask “Why should i go for Instant?”
If you have paucity of space “Although if you have terrace but you don’t wish to spoil your space for other things, Even then it doesn’t means that instant is the only option for you?”
In that case it is primarily depends on – Do you have high flow shower fixtures?
If : No.
Then : Do you have ceiling height available to put in your water heater?
If : No.
Then : 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?
If : Aesthetics is not an issue with you, but personally you don’t like anything bulky protruding from the wall.
Then : Either you can go for instant or centralized water heaters and i would suggest you to go for centralized water heater of 300 Liter Capacity.
But yes we did calculated the capacity as 170 Liter, and why you should not go for instant?
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. Let’s 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.
Now why instant may work for you?
If your city has severe winters then you may have to heat up hot water on a similar scale. And if you have not any rain shower, then 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.
So, the capacities are works here.
Now what about heating mode, what you should opt for, Solar, Electrical, Gas or any other alternate technology?
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.
And through above calculations, 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.
What if you opt for Gas Only?
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.
Now your question would be in how much time Solar is able to recover its investment?
Well 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?
Now you will say that it depends on usage as well, the higher the usage, more the recovery.
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.
Now what about Heat Pump?
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 let’s 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!
Well now, I think that you know what you have to do with your house, first of all you would choose your fixtures and then you will decide on the hot water system.
It’s such a simplistic topic, and yet there is acute dearth of professionals in this industry (Hot Water),
Thanks for joining me for these water heater tips! My goal is to share ideas to help everyone related to recent advancement in hot water technology that is the basic necessity as the season changes or whenever you are planning to construct a new house or planning for the renovation. Join us for your experiences, discussions and queries.