The Difference Between Low and High Efficiency Water Heaters

Dr. Energy Saver's owner and president was On the Job down in Florida helping us understand how to make homes more energy efficient in warmer areas of the country. Today, he focuses on how windows can lose or conserve energy.

High Efficiency Water Heating

Today we are going to talk about high efficiency water heating and water heating is important because it can account for up to 15% of your overall energy bill in your house and actually more than that if you have more people in a smaller house.

Hot Water On Demand

The Water Heater only runs when you turn on the hot water and then what will happen is as the water flows through here the gas flows in and out heating it up as it goes through the bunch of burners inside here and exhaust the hot air out of here. The water flows back through the house. You are only using it as your demand calls for it; so, you are not spending a lot of extra money.

Read Full Transcript:

Larry Janesky: Hey. I'm Larry Janesky from Dr. Energy Saver.

Kelly Lafler: Hey. I'm Kelly Lafler from the Orlando, Florida area from Dr. Energy Saver.

Larry Janesky: Today we are going to talk about high efficiency water heating and water heating is important because it can account for up to 15% of your overall energy bill in your house and actually more than that if you have more people in a smaller house. So here we are looking at an electric water heater.

Kelly Lafler: Correct. Now we have an old electric water heater that they have tried to make a little more efficient by putting in some wrap around it as you can see. Larry Janesky: Right, so if I feel the top of this water heater it is hot. I mean right here it is pretty hot to the touch.

Kelly Lafler: Yes, it is and we have an electric element in there that is just consuming electricity here. They do have it on the timer, but of course you know, if we shut it off for 6 hours a day, while you are at work the tank is just going to cool off and you'll have to heat it all, again.

Larry Janesky: That takes a lot more electricity just to heat that thing back up. All right, so an electric water heater could cost you as much as $50 a month just for the water heating component on your electric bill and I can feel this pipe and wow, it is really hot. This is from the hot water coming out. But when I feel this and it should be cold right here. This is the cold water coming in and man this pipe is hot.

Kelly Lafler: Wow.

Larry Janesky: And why is that?

Kelly Lafler: It looks like what is happening is you are getting some radiant heat coming back up from the tank with - pipes aren't insulated and you are correct that its really, really warm coming back through there.

Larry Janesky: So thermal siphoning and we have got you now. So, we got a lot of heat and we look at this with a thermal imaging camera. We see a lot of heat coming off this water heater and also the sides of the tank. Now here we are in Florida, we are in a cooling climate, which means most of the year we have our air conditioning running.

Kelly Lafler: That is correct.

Larry Janesky: So, here we are adding heating load inefficiently and very expensively the water and that allows heat to escape back into the house environment.

Kelly Lafler: You have to run your air conditioner more to cool her back down.

Larry Janesky: More electricity.

Kelly Lafler: That is right it runs all day.

Larry Janesky: Electricity to heat the water inefficiently and we get this radiant electric heat coming off of that and then we have more electricity to get rid of it. It just doesn't make any sense.

Kelly Lafler: No, it doesn't.

Larry Janesky: There has got to be more efficient way.

Kelly Lafler: Yeah, there is.

Larry Janesky: Is there?

Kelly Lafler: Yes there is.

Larry Janesky: Let's go take a look at it.

Kelly Lafler: All right.

Larry Janesky: All right Kelley here we are and we are looking at the efficient alternative to that big old electric tank style water heater, what is this?

Kelly Lafler: That is correct, what this is here, is a gas tankless hot water heater.

Larry Janesky: All right, so what it is going to do is make hot water on demand.

Kelly Lafler: That is correct, when this unit only runs. It only runs when you turn on the hot water and then what will happen is as the water flows through here the gas flows in and out heating it up as it goes through the bunch of burners inside here and exhaust the hot air out of here. The water flows back through the house. You are only using it as your demand calls for it; so, you are not spending a lot of extra money.

Larry Janesky: So, we don't have a tank of water that we are trying to keep hot all the time.

Kelly Lafler: That is correct.

Larry Janesky: All right, and if we had a gas tank style water heater, we heat up the water. It cools down again up through the flue and we heat it over and over again even if we are not using it. With this there is no tank at all so we are not taking a reservoir of water.

Kelly Lafler: Right.

Larry Janesky: Okay. And now we are in Florida and we have this unit mounted outside. Now it is something that we don't see up north, where I am from, but this is the vent right?

Kelly Lafler: Yes sir.

Larry Janesky: Okay, so the exhaust gasses come right out of here because this is a high efficiency unit. The way the heat exchanger is designed so that hot combustion gasses go through this heat exchanger as the water goes through there. Most of the heat from the combustion gases is transferred to the water.

Kelly Lafler: That is correct.

Larry Janesky: In fact, this is 90.

Kelly Lafler: It is about 90% efficient.

Larry Janesky: 90%

Kelly Lafler: Yes sir.

Larry Janesky: Only 10% of the heat from the combustion gasses are going to be lost to the outside where a typical gas water heater, tank style water heater that might be 15 years old, will be, maybe, 65% efficient so that means 35% of the heat that you paid for either in gas or oil is going out up the chimney.

Kelly Lafler: Right you are just losing straight out.

Larry Janesky: All right.

Kelly Lafler: So this is much more efficient and we also don't have the risk that this tank. Well there is no tank but that a tank is not water heated would leak, would flood your house.

Larry Janesky: Correct.

Kelly Lafler: This is what we do, we lose water to the outside as you can see you would not ruin any floors, you wouldn't ruin any walls, nothing.

Larry Janesky: Right now, imagine down here in Florida where they don't have basements and the tanks-style water heaters are located in the utility room on the same level as living space when one of those let's go.

Kelly Lafler: You are right it just floods the whole house.

Larry Janesky: It floods big and you know carpets, rooms and flooring.

Kelly Lafler: Yes sir.

Larry Janesky:So, no risk of that here even if this was located inside because it is no tank.

Kelly Lafler: That is correct.

Larry Janesky: All right and now we also have a modulating gas valve so if we there is a flow sensor in here and if we are only using a little bit of hot water it would only have a little flame make a little bit of hot water.

Kelly Lafler: Right, that is what it does. You can take it in. It only will heat what you are using, shuts off as soon as you are finished using it and then just comes back on whenever you turn the hot water back on. So again you are not using a tank. You are not going to run out of hot water for showers. You are not going to run out of hot water for doing dishes. It is just going to continue to run as long as you are asking for hot water.

Larry Janesky: So a tankless water heater even though it is smaller will cost more than a tank style water heater, but it is worth it because we spend a little more in equipment when we buy it over the life of this unit which could be...

Kelly Lafler: You could run it 15 to 20 years.

Larry Janesky: So over 15 or 20 years where you use a lot less gas running through here and it will make that extra investment in equipment initially seem well worth it. We are going to save many times that.

Kelly Lafler: Yes, you will.

Larry Janesky: Beautiful. All right Kelly, well looks like we need to go equip the world with tankless water heaters.

Kelly Lafler: Yes we do.

Larry Janesky: All right.Dr. Energy Saver Contact us for a home energy evaluation and written estimate.