Hot Water Options

I've got a 2200 sq. foot ranch house with a centrally located 40 gallon propane hot water heater and a master bath 40+ feet away as the copper runs. The master bath contains a two-sink vanity, large show and a whirlpool tub. I'm in the process of re-doing the bathroom and would like to relocate the water heater to the garage which is possibly a 90' run from the bathroom.

Since it's very hard to even get a plumber to return a phone call I'm trying to gather as much information as I can on the various options. Namely,

1. Move the hot water heater and install some form of recirculating system. I'll still have quite a temperature drop to the master bath I would think. The water heater should probably be enlarged, but that could be determined later.
2. Install a large tankless system in place of the tank. This might be attractive if these can legally be installed in an attic space as the heater would remain centrally located. There are only my Wife and myself living in the house so the instantaneous demand is not too bad. Advantage to this location is that a vent already exists in the roof
3. Move the hot water heater, but install a tankless water heater near the master bathroom. This would provide "limitless" hot water and almost instant on. The main disadvantage is that an additional roof vent would have to be cut unless these units can be vented horizontally.

I'm completely open to suggestions and would be grateful for any advice offered.

Rick T

How about a small electric tankless? You could locate it near the master bath and run the hot water line from the gas water heater to it. It would then heat the water in the line which would be room temp. and assist, if necessary, in heating the water from the gas WH when it got there.

Just a thought.

It would also depend on your present electric load.

If you get a small electric unit. Run it as hot as it will go, and use a tempering valve. It will make it seem like a larger unit. You will increase your standby losses though.
You can still re-locate your water heater 90' away. Just use recirculation, like you said, but insulate the bejesus out of the pipes. McMaster-Carr has poly-urethane insulation 2" thick. That's R-10.5 !

Point of Use Heater

You could install a small tank type heater such as the 2.5 gallon Ariston GL2.5, and feed it from the gas water heater. Just put the heater in your hot water line at the point of use. The heater is 14" x 14" x 10.25" and operates on a 115 volt circuit with about as much power as an electric teakettle. They cost about $140 on-line and $145 at Grainger. Google Ariston GL2.5.

If you don't need a lot of flow such as with a half bath, you could eliminate the hot water line.

Ninety feet of 1/2" copper contains about 1 gallon of water. The initial flow will be from the electric heater. As you use hot water, the water in the pipe from your gas heater will mix with the water in the electric heater and the temperature will drop a bit but still be hot. If you use more than 1 gallon of water, the hot water from your gas heater will make up the temperature. You will get a little temperature variation during the first 3 gallons of use but you can install a tempering valve if that is a problem.

I believe the local tank heater will be more efficient and probably less expensive than a recirculation system. It will certainly be less expensive than a tankless electric heater which often requires a 230 Volt 40 Amp circuit.

50 gallon in the garage

install a 50 gallon in the garage and just
put a timer pump on the line if you really are
worried about the instant hot water....


why not just install the heater
and try it first without the pump, you might
be surprised...


you will be better off in the long run
not to make things too complicated


keep things simple --keep things easy

just my opiinion

Tanks?

Just when I was about to get carried away and go tankless I reread this original thread. Darn!

Recap: Laundry room and kitchen on one end. Master bath and guest bath on the other end. 80' apart (L-shaped ranch). I've currently got a 50 gal. HWH centrally located with a non-functional recirc system going toward the master bath. I'm installing a 70 gallon whirlpool tub and really need enough hot water to fill it. Just my wife living at home so there is not a great laundry or shower load.

If I relocated and enlarge (75 gal?) my HWH to the far side of the garage it will be 90' of copper from the master bath. Assuming 50 psi pushing 90' of 3/4" copper and a 50 deg. attic in the winter, how much temperature drop could I expect while filling the tub? What's the best way to insulate the pipes? I'm familiar with the standard slit gray tubular insulators, but is there a better way?

Keeping it simple makes sense. I think my engineer mentality was getting the best of me thinking about the "point of sale" benefit of a tankless WH located right outside the master bath.

I should note that I do have the MB down to bare studs as part of the rebuild so the plumbing associated with a tankless WH would not be a big deal (except for the gas).

More opinions would be greatly appreciated.

Rick T

keeping things simple

I honestly dont thingk anyone here is going to be able to
calculate the temperature drawdown on those pipes and
the amount of loss in $$......


I used to be able to calculate solar systems years ago
and the heat loss ect, ect.....its was basically all mental
if this and if that bs.... guessing what the r factor was
in old homes ect ect.....no concrete answers...

basically whatever it took to make the customer feel like he was
saveing big dollars.on solar panels . to sell the job.....
------------------------------------------------------------------------

just insulate the pipes with some rubber insualtion and forget about it...
cover them in the attic with extra insualtion for fun if you so wish...


for extra measure the absolute best palce to save is to insulate the 75 gal
heater with a blanket thats where the big saveings will be

somewhere in the 25% of your yearly costs of operateing theheater....


you can only squeeze sooooo much blood out of a turnip....

do the best you can and forget about it...

http://www.askthebuilder.com/451_Tankless_Water_Heaters_-_Some_Surprising_Facts.shtml

Mark,
Thanks for the reply. I certainly will insulate the HWH and will have plenty of room in the garage to do so. The garage is actually a very good location as it's closest to the kitchen and laundry room which have hot water needs at random times during the day. I can set the recirc timer to cover normal bath/shower times in the distant bathrooms.

Rick

I would suggest you seriously consider a recirculating system. Laing is one of the companies that make them. The model with the timer would perhaps fit your needs best. The attached link takes you to their site. The strong point of the recirculating system is that you would be able to have instant hot water at every fixture in the house, provided you connect the recirculating line to the fixtures. The point of use heater will work fine for just that single outlet.
http://www.lainginc.com/howhot.htm

Gary,
Thanks for the additional input. My plan now is exactly as you described: Larger HWH (because of the whirlpool) and because of the relocation to the garage I should easily be able to put the kitchen and the guest bath on the recirculating system. I'll not bother with the laundry room as it's very close to the new HWH location. This approach is low risk and modest cost.

I do agree with some of the other threads that it might have been hard to find a plumber to work on a tankless system. In my area (Hollister, CA near San Jose) it can be very difficult to get a plumber lined up even for conventional work.

Rick

Be sure to insulate both the hot water supply and return lines to cut heat loss. A pump with a timer would lower operating cost and save the water heater for working when it wasn't needed. My system does not have the timer, but I love the instant hot water.