I have a vacation home that frequently has 10+ guests staying there. The hot water heater just isn’t big enough for the peak loading that results. It’s pretty new though, so it seems silly to just get rid of it. Is there any sense in adding a second hot water heater to the system? Or am I better off just replacing it with a much larger one or an on-demand system/
4 Likes
What type of water hearter you are using ?,Its advisable to change your water heater to instant water heater no mater how small it is it will still serve you the best …The instant water heater works continuosely as water got into the water hearter tank.water-heater-constant-running.
Sounds like a ski lease, Keep your tank and use a continuous flow (instant hot) to pre heat the cold water going into your tank HWH. (pipe in series) Here, in Tahoe, the water going into the continuous flow heater is too cold for it to work by itself and satisfy user unless, the unit is $oversized$. But, using 6 to 9 gpm to pre heat water going into a tank works great for more capacity and efficiency. (530) 587-4944 Majestic Heating & Ventilation CSLB 906991 C-36 and C-20
gas or electric?
the electric units are not real good imo.
looks like a capacity issue, if you have gas i would suggest a tankless unit. i currenty have a yoga studio that i build with 3 showers running at same time after class on one 9.2gpm unit.
if you dont have gas i would replace unit with larger size, 80 gallon, this will not require additional electrical or plumbing, adding a recirculation pump will speed up time for hot water at fixtures, a timer on the heater will help save money,
steve
generl contractor FL
Tankless would be the most energy efficient in the long run,as tank heaters have a slower recovery rate. Obviously a home that is being used by that many people using the shower,tub,and sinks can empty a 40-50 gal tank pretty fast. I have installed plenty of tankless units in residential and commercial applications. Some may be pricey on the material end,but will pay for itself down the road.
To find out tank capacity and how many BTU’s needed for gas units,count all your fixtures and add up the total GPM output. If you don’t know the output of each faucet,I have a rule of thumb calculation that works for me.
Bath sinks 0.5 -1.0GPM
Tubs 2.0 GPM
Utility sinks 1.5-2.0 GPM
Kitchen sinks 2.0 GPM
Showers 1.5-2.0 GPM
Or of course the old school trick of filling a gallon jug or measuring container and see how much water is in containe after 1 minute
I always pad each faucet in my calculations by at the very least 1.0 GPM per faucet so it will increase the BTU’s produce faster recovery.Especially in vacation homes. For restaurants and commercial, I increase the calculations even more for health codes where you have to have maintain consistent flow of a minimum of 120 degrees with all faucets on.
For homes of this type, you want to have repeat and happy guests, so cover your bases. I would also use water saving diffusers and shower heads.
Install an energy efficient TANKLESS water heater.
It will save you energy when the house is not occupied and an ENDLESS supply of hot water when large crowds are staying there.
Though they are more expensive, they take up less room, are not prone to leaking, save energy and provide an endless supply of hot water.
To me, it’s a no brainer!
With 10 guests, an on-demand system would be my first choice. They can actually be a little more expensive to operate under heavy use, but for a vacation home that is not used year around the benefit of unlimited hot water would outway the cost factor.
Solar Thermal is your best answer. call 561 312-8223 i can help you
go tankless it is the best rout for your needs cost more to purchase and install but in the long run you will save money
I suggest that you call a local heating expert who can advise you of what will work best for your specific locality, environment and build site. S/He should be able to give you a clear picture of your options along with a quote. Good luck with your project!
Put in a bigger one.
I would add a tankless unit onto the line of the existing unit. The water would heat up faster in the tank ( if the tankless is put before the supply line ) and when the tank runs out of hot water the tankless unit can supply the hot water.
If you have the space I would also add a tankless unit to the shower/bathtub areas. Many homes now have very large tubs which require lots of water. I like adding lots of insulation around the tubs and provide them with their own tankless units.
Your question really needs a few more specifics to be answered correctly:
-
Is your water heater gas, electric or oil fired?
-
Depending on which fuel source you have available, can that utility be up-sized to carry another or larger heater?
-
Are you presently using water saver devices?
-
How many baths/showers are used simultaneously?
-
Can your guest take showers at different intervals or do they all need to shower about the same time?
Without the answer to these it’s difficult to give an answer for your specific situation. However, I’ll give a generalized answer that should apply to a large percentage of homes that may be in this situation.
if you have gas (natural or LP), and if the gas line can or will be able to carry another appliance, then I would recommend that you install an on demand heater in series with your present tank. Connect the on demand to pre-heat the cold water and then dump it into the cold inlet of the tank. This will give you the firing capacity of both units as well the storage of the tank.
if you have a gas or oil fired boiler, then I would recommend that you install a properly sized indirect heater that is fired from the boiler. It should be setup for the boiler to give priority to domestic water heating. Then I would pipe and valve it to either be in series or parallel with your existing heater. A couple of extra valves would allow it to be operated either way depending upon which is more suitable for your situation.
Since there is no “one size fits all” solution to your problem, the best thing you could do is have a qualified pro come to your house and do an “on site” evaluation and make recommendations.
A tankless water heater will give you the a constant flow of hot water when those 10+ guests are staying there and no cost when the property is vacant. However, the energy requirements for a tankless system are much higher. The first factor to consider is whether you have gas or electric. If it is an electric water heater, you will have to upgrade the existing circuit to the water heater in order to use a tankless system. The cost of an electrician can be a prohibiting factor depending on the distance and difficulty of running the new circuit. A gas system will have similar, but a different set of problems. Water heaters are typically run of off a 1/2" gas line. A tankless water heater will require at minimum a 3/4" gas line. A qualified plumber will be able to run new gas line. The cost of will be determined by whether or not the new pipe can be piped into existing pipe in the home or if the pipe needs to be run all the way back to the meter.
Running an additional water heater in series will also bring up a couple of problems. If it is electric, you will need an additional circuit wired. If the system is gas, the same may be true for the gas line.
Replacing the exisiting water heater with a larger heater is also an option. Larger gas water heaters require a 4" exhaust opposed to the typicaly 3" exhaust.
I would evaluate the costs of each of the options with a licensed contractor. Long-term tankless is going to be the best way to go, but you may not have a budget to put one in at the moment.
Based on the fact that your tank is newer, It would be most economical to twin in another tank. I would also suggest matching the existing tank make & model so that you get even draw out of tanks. In non high demand times you can shut off the gas and water supply to one of the tanks and save that way also. Next time around I would suggest an on-demand system.
There are a number of factors that say you could increse the size of the water heater. First is the flue exhust large enough, is there enough pysical space for the new larger tank, Is the gas supply large enough for the larger burner BTU need. and have all the local codes been followed when the origional tank was installed. we have found that 80-90% of water heaters we replace were not installed correctly and there are redesigns and upgrades needed to install a new tank correctly.
Tankless Units are a very good option for you, depending on your space availability. They can be added to the exisitng tank or 2 of them can be twinned together for a higher output- up to 15 GPM. Twinning two tanks together are another good option- less money on investment.
The best way to solve this problem in today’s economy and with the growing concerns of energy consumption concerns. Would be to install a tankless water heater. This would give a endless supply of hot water. As well as offering you the most energy efficient way to heat hot water for your home.
An on-demand would be more cost efficient versus a bigger or second one simply because you will be running a bigger one even when you don’t have 10 people there; that can get quite expensive…
Hey Ryan,
It’s always better to replace one with another as opposed to adding a secondary (for several reasons, space being one), but you should consider changing it out to a “tankless water heater” for BIG TIME energy savings!
Jim at All Temp Refrigeration, Inc. Santa Clara, CA.