Building a new home - 1 tank or 2?

[jimbo]

We will be using LPG as our fuel where we are building. Can any "gas" tank heater be converted to LPG? I cannot find anything on the BW website that states specs about the GX-1-55S6BN being able to be ran on propane.

NO. Water heaters cannot be converted from nat. to LP. You must buy a purpose-built LP model.

[gusherb94]

When you order the unit from the plumbing supply just tell them its for LP gas Here is the link to the LP unit http://www.bradfordwhite.com/product...product_id=179

I have installed a few of the GX-2-25 already, everyone of my customers loves the unit. They are able to fill their 80 Gallon soaker tub and there was water left over to shower or wash dishes. The unit also recovers really fast as well.

Would you say that water heater is enough to serve a building with two apts each with one bath one washer and dishwasher and a store with a sink for light dishwashing use?

[SewerRatz]

Would you say that water heater is enough to serve a building with two apts each with one bath one washer and dishwasher and a store with a sink for light dishwashing use?

I have seen the GX-2-55 handle a two flat with no complaints. Granted the lay out is pretty much what you said less the store with a sink. Worse case scenario is you install it and it can not keep up you can always add a storage tank with a recirculation pump and an aquastat to give you a bit more of a buffer.

[riverside67]

I would prefer not having a recirc system and the reason I need to decide is that the 2nd water heater is taking up valuable space in our floor plan. If I do not really "need" that 2nd heater then that space can be re-captured into the home. Plus it would mean somewhat less piping, etc (i.e. ..cost)

[SewerRatz]

The recirculation system I was talking about is for the storage tank. IF the storage tank water temp goes down the pump would turn on and start heating the water. Have a look at this piping diagram.http://www.hotwater.com/lit/piping/A0380.pdf I do service work at a restraint that has this exact set up with the vertical tank of 180 gallons, that Burkay boiler can turn that 180 gallons of ice cold water into 180° F in 15 minutes.

Now what I was saying is you put the GX-2-55 in the place of the boiler and install a 50 gallon storage tank, you should have endless amount of water.

[riverside67]

Now what I was saying is you put the GX-2-55 in the place of the boiler and install a 50 gallon storage tank, you should have endless amount of water.

Hmmm...interesting idea. I will have to think about that one for a while.

I don't think I ever stated this info before. The mstr bath and bath #2 in the home are both about 75 feet from the tank heater in our garage. If we install a 2nd, as it's currently designed, then those distances become 20 and 30 feet, respectively.

[riverside67]

Anyone have any input regarding the distances of the water heaters to the master bathroom and if 75 feet is too far for typical uses?

[riverside67]

We are finalizing our building plans and I really need to decide which way to go for our hot water needs.

Should I go with two different tank heaters in the two different locations or should I use one heater and one storage tank in the garage to serve the entire home (knowing the master and bath #2 are 80 feet from where the heaters would be in the garage)?

Thanks

[jadnashua]

Assuming your supply line is 3/4", there's about 7 gallons of water in the pipe from the WH to the furthest location (shortest distance which may not be valid). Unless you use recirculation, you'll throw away about that much water in the pipes that has cooled off to get hot, and take about a minute or so to do it (at a tub), probably longer, especially on a sink or shower which can only flow maybe 2.2gpm.

So, unless you can put the tank closer to the point of use, or do something else to mitigate that, you'll probably not be happy without recirculation or a small tank in the bathroom to take up the slack before it arrives from the main source.

[riverside67]

So what if I was to install two - 25 gallon high performance Bradford White GX255S6BN water heaters in the garage (plumbed in either series or parallel, whichever is better) with a recirculating system?

Supposedly these 25 gallon heaters can provide 155 gals (each) of hot water in the first hour. This would mean an available 300+ gals of hot water with a recirculating system.

The only thing...how do recirculating systems work and are they subject to problems?

My supply lines from the heaters to the master and bath #2 will be 1" minimum.

[jadnashua]

A single tank would likely have lower standby losses. not familiar with that tank, so don't know the details.

There are all sorts of recirculation systems. If you can provide a dedicated return line, it works best, but using the cold works with some compromises. Lots of discussions here on this subject, use the search function. If there's any way to place a heater closer to the point of use, you could likely eliminate the recirculation. Cost to use it isn't huge if you insulate the lines and can live with it on a timer so it doesn't run when you are unlikely to need it.

[riverside67]

Considering this is new construction the recirculation line should be simple to add to the plan.

Is having two tanks in series a big waste of money? My wife and I love long hot showers and will have a soaking 100 gal tub. I really think we need this much hot water avaiable.

Do recirculation pumps need to be sized based on certain criteria?

[riverside67]

After doing some research last night I am leaning towards using the Grundfos UP10-16 recirc pump with a dedicated hot water return line.

Now the only thing I need to decide is what type, and how many, water heaters I'll need in the garage. I'm still thinking at least one BW high performance GX1-55S6 or GX2-25S6 and/or possibly two of the 25 gal units in series with the first one set at a lower temp so as to not waste too much propane but to keep the water warm basically to pre-heat for the 2nd tank.

We have decided to eliminate the water heater in the master WIC for a coulple reasons, distance from water softener (which will also be in the garage), possible noise from the unit coming into our mstr bdrm, and most of all loss of valuable space in our WIC (that is very important to the wife FYI).

Also, since we will be using a private well and septic system it makes sense to utilize a recirc system to eliminate unecessary pump runs and cold water going down the drain and into the septic tank on a daily basis while we wait for hot water to get to the point of deliveries.

Please let me know what you all think of this scenario.

Thanks for all your input.

[hj]

IF the parallel installation works "perfectly" and few do after a couple of years, then you get the SAME amount of water from either a parallel or series installation, and since you have two burners with either one, the recovery is the same also. With a parallel system, the two heaters MAY fail at the same time, but not likely, however, unless the new heater is exactly the same as the old one, you lose the "mirror image" requirement of a parallel installation, so you almost have to replace both heaters anyway. With a series installation, which is the only way I have ever installed two heaters, the first one will outlast two or more second ones and there is no possibility of "short circuiting" the flow, and the two heaters can be different makes, models, or sizes.

[riverside67]

Ok, so maybe it would be better that I connect two tanks in series.

Would an "in series" design basically be where the hot water from tank #1 feeds the cold water inlet to tank #2 and the the hot water out from tank #2 feeds into the home?

If I went with this setup how would a dedicated hot water return line be plumbed into this setup?

Thanks