do I need more hot water capacity? how do I get it?

[starfish11040]

I have a building of ten small apartments. Total of twelve people. One tenant is complaining of sometimes not getting hot water for his showers on weekday mornings. He says nights and weekend mornings are no problem. My guess is that it's the morning rush and the lack of hot water is due to a temporarily insufficient volume of hot water because too many people are showering at the same time. Is there anything that can be done? Other than to go thru the expensive job to replace the tanks with larger ones?

[havasu]

Have the tenant who is complaining wake up a bit earlier so they can get a hot shower! Seriously, I would first do some maintainance on the existing water heater. When was the last time it was flushed properly. You could have a large amount of sediment at the bottom of the tank, making less hot water. If ths is not the case, you have a few options.
1)Add a larger water heater.
2)Add a second, smaller hot water heater which would work in conjunction with the larger one.
3)Add a solar collector, subsidized by the government, which will replenish hot water faster.
4)Trunk all your water lines, so all will receive the same amount of hot water.
5)Install hot water tanks under the bathroom sinks, leaving the main hot water heater for shower usage.
6) Evict the complainer!

[starfish11040]

Somebody mentioned installing a tempering valve. Would that extend the hot water capacity?

[havasu]

I doubt it. You could also reduce the flow of hot water to each of the units, but all that would accomplish is reduce pressure to the units and make your tenants take longer showers with less cold water in the mixing valves.

[havasu]

Product Description
Watts Series 70A Hot Water Extender Tempering Valve 3/4" (0215500)

No. 70A furnished in 3/4" size with copper connections. Series 70A Hot Water Extender Tempering Valves Sizes: 1/2" - 3/4", meets various installation requirements. They are available with sweat or threaded connections. Temperature range 120° to 160°F (49° - 71°C). The hydraulically-operated thermostat opens a spring loaded check in the cold water inlet allowing cold water to mix with the hot water. They have unusually high capacity for their size. For example, the 3/4" (20mm) 70A-T used for smaller domestic and residential requirements, passes over 10 gpm (38 lpm) with a 10 psi (70 bar) pressure drop. Maintenance is simple too, as the thermostat is easily removed and replaceable as a unit. Valve bodies are of brass construction that is recognized and required to resist corrosive domestic hot water conditions.
***WARNING*** WATTS HOT WATER EXTENDER TEMPERING VALVES CANNOT BE USED FOR TEMPERING WATER TEMPERATURE AT FIXTURES. SEVERE BODILY INJURY (i.e., SCALDING OR CHILLING) AND/OR DEATH MAY RESULT DEPENDING UPON SYSTEM WATER PRESSURE CHANGES AND/OR SUPPLY WATER TEMPERATURE CHANGES. A.S.S.E. STANDARD 1016 LISTED DEVICES SUCH AS WATTS MODELS L111 OR MMV SHOULD BE USED AT FIXTURES TO PREVENT POSSIBLE INJURY. The Watts Hot Water Temperature Control Valves are designed to be installed at or near the boiler or hot water heater. They are not designed to compensate for system pressure fluctuations and should not be used where ASSE 1016 devices are required. These WATTS valves should never be used to provide "anti-scald" or "anti-chill" service. When installing the Series 1170 valves in a radiant heat application, the components of the radiant heat system must be of materials with a construction capable of withstanding the high limit output temperatures of the heating boiler. If you are uncertain as to the product's adaptability for your application, please consult an authorized representative before installing or using the product.

[havasu]

Sorry for the additional replies, but I've been brainstorming your problem. Have you already installed low flow shower heads? This would limit hot water consumption, provided you have good water pressure. Also, depending on where you live, you may receive rebates from your water company for trying to be a "greener" complex.

[starfish11040]

thanks.
I've been gradually installing low flow shower heads but most of the apartments still have the old ones. I should do more. It will help but i don't know if it will be enough.
Just to clarify. You posted a description of a tempering valve. Does that mean you think it is something worth doing?

[Reedwalker]

What type of water heating system do you have?

For 10 units I'm assuming you have a boiler with storage tank.

[havasu]

Originally Posted by starfish11040

thanks.
I've been gradually installing low flow shower heads but most of the apartments still have the old ones. I should do more. It will help but i don't know if it will be enough.
Just to clarify. You posted a description of a tempering valve. Does that mean you think it is something worth doing?

This is an option, but first check your tank to make sure it is clean, well insulated and efficiently running. From this point, I would complete low flow fixtures in all of the units. Not only the shower heads, but all faucets in the dwellings. Most cities make this a must, and you want to be as "green" as possible for the environment. If at this point, your tenants are still complaining, you could try a tempering valve, but don't get too excited if their complaints change to them not having enough water pressure. All other options will cost you considerably, so lets hope these cheaper upgrades help first. Please let us all know the outcome...and good luck!