Domestic water heating for a restaurant

andrewd33

My family owns a medium sized restaurant/bar and my father recently passed leaving me in charge of the building. I am an HVAC contractor but do not do hot water or boilers in my company. I am looking for a good recommendation for this application and possibly a contractor to partner with. The plumbing co we normally use was recently sold and I am not sure I am getting the best advice. Currently there are two separate atmospherically vented water heaters in the basement vented thru the masonry chimney (approx 6x12 clay lined inside dimensions). The one is a 75 gallon 75,000 btu unit that delivers hot water to the pot and pans sinks and the low-temp cube type dishmachine. It is a residential model as the prior unit failed with the previous owner of the building 10 years ago on a Saturday and he didn't have a commercial unit available so he installed the resi with a disclaimer on the contract. Ironically it is still working 10 years later and the prior commercial same size and capacity (American Std) failed after 4 years). There is another 40 gallon unit that is about 4 years old that provides water to bathrooms and hand washing sinks via a mixing valve and untempered water to the low temp glass washing machine behind the bar. The specs on both ware washing machines show around 6gpm per machine and use approximately 1.5 gallons per cycle. Cycle times are approximately a minute and 30 seconds per batch.

At first I was considering a tankless type heater with a 50 gallon buffer tank and having all repiped to serve the two diverse loads. (Higher temp for warewashing and tempered for handwashing). I am concerned because we have hard water though. There is a water softener present that we don't use and I get mixed reviews of pros and cons on using softened water vs not softened water. I have a feeling the prior owner who had the contract with Jason softening may have failed to change anodes and was softening water which may have lead to premature tank failure. We acquired the building one year after the 75 gallon unit was replaced and have passed thru 9 years so I know it is on borrowed time at this point. Believe it or not we rarely run out of hot water. Normally Mothers day and Easter are the only days because we are so beyond our peak on those days.

The current plumbing co recommended a Bradford White 60 gallon 199,000 btu unit to replace both. Considering the cost I am wary of putting that much money into a tank that even BW claims depending on its use and water conditions could last 15 years or could last 4 years. Does anyone have a better recommendation? Perhaps Navien with external buffer tank or a lower efficiency Lochinvar. We keep our water heaters set at 160 so I can't see the efficiency of a condensing paying us back. Just need to meet the venting and height requirements to make this replacement go smooth.

Thanks for any input.

Rich_49

Here is your best bet .
http://www.htproducts.com/phoenix-sanitizer.html

The tankless will take an asskicking and require annual service to keep the heat exchanger in a well condition . The storage tank is a space taker . The design of the heat exchanger in the HTP requires much less service , the unit will do all you want and with a couple mixing valves for different temp applications will serve you well . Others here may be able to verify these claims based on knowledge of how such things work .

Where are you located ?

Zman

Domestic water for commercial kitchens is often regulated by AHJ. I my area it is passed down from the state health department.
You are required to provide the size of the sinks, the specs of the dishwashers and fill valves ect. From there, you do some math and come up with the required water heater output and storage capacity for approval from the health department.

andrewd33

Rich we are in Verona. I never heard of the HTP product and I have to agree I am not a big fan of tankless units. My biggest concern is getting the right product for the application and making sure that my local city water which is pretty hard won't destroy the new tank. The only reason I considered tankless with a buffer tank is I figured if one section fails I'm not out an entire unit. I hear so many mixed things about if you have hard water you will calcify the tank. If you soften the water the residual salt and lack of minerals will attack the tank. When I got the recommendation for the Bradford White unit from the outfit I normally deal with it seemed expensive which doesn't bother me as long as I am getting something that will give me 10 years of service. I want to get a new water softener and use it as we don't put salt in the old Jason unit that was left behind. I have been afraid to since I thought it may ruin the existing tanks their. We don't need 180 degree water, in fact the health department came in we were ready to do the sink fill test and the dishmachine temp test and they basically told us that as long as you are using a chemical method for sanitizing they weren't concerned with the temps. The Low temp machines give better results with hot water from a cleaning perspective but as far as sanitizing the chlorine is introduced to the tank during the rinse and there is a paper strip that confirms that it meets the board of health codes. We do maintain 155-160 on our tank units, however on a busy night the water temp will go down to 125 during a peak load period for an hour or so. As far as efficiency goes, I am not too concerned. A gas is pretty cheap and looks like it will stay their for a while. and B the fact that we keep our water at 160 I don't see how much condensing we are going to be doing. I assume that the hotter you heat the water the unit will condense less therefore the general AFUE will be lower.

Rich_49

Verona NJ , Andrew ?

This unit is specifically made for Restaurants and the like . Many have not heard of HTP , quality often goes unnoticed . This really is the unit you want and need .
Just as an advisory . Cold water always enters a water heater and as such they condense regularly and AFUE is rarely not achieved .
Getting a 10 year warranty on a commercial unit will be difficult from any manufacturer . If hotter water is not really a concern look at Phoenix Multi Fit or just the Phoenix . These units have replaced high end (LOL) AO Smith units that had big problems and to my knowledge are performing as advertised and in the way they were designed to .

4Johnpipe

Andrew Rich and I have a HTP Plus unit installed in a 3 story nursing home facility. It serves the laundry and commercial kitchen while saving the customer $400.00 a month.

andrewd33

John I will email you with my contact info. I am not expecting a 10 yr warranty. But for the amount a commercial heater sells for it should give you 8-10 years of service if it is maintained. I too in the HVAC field suffer from great disappointment in Manufactured product performance. Even on higher end Trane and Carrier products we have seen premature failure rates that are surprisingly higher than previous generation equipment. And earlier in their life cycles than ever before. Therefore I am wary to spend thousands more on a product that may save that in a typical life cycle but will fail earlier than the inefficient prior generation simpler equipment leaving a net increase in life cycle cost. I guess we have the govmint to thank for that with the relentless pursuit to squeeze 200,000 btus from a single therm of gas that only nets 100,000 at 100% efficiency. Can u blame VW? Lol

4Johnpipe

Andrew it may not be as $$$ as you think...