Sizing Domestic HW for Laundramat

tim from Reed Wright

contact AO smith, been using there sizing charts for years. Never had a problem.

Jeremy

Sizing Domestic HW for Laundramat

Was wondering what load calc. to use to figure out domestic hw in a laundramat. Laundramat has 18 regular washers and 3 commercial washers. Cust. needs new boiler and was wondering what is the best route for him. Cust. is not opposed to indirects. Any help is appreciated.

Thanks,

Jeremy

Jackchips

Hi Jeremy,

All the major manufacturers of hot water heating equipment have sizing formulas. You should be able to get a design chart from a supply house. They are very easy to use and you should follow them closely. If you work with a manufacturers rep they will usually guarantee that their equipment will meet the demand.

I'll let the installation experts advise you on what equipment to go with.

Bill_14

Plumbing Engineer

Several years ago, there was a good design article in the Plumbing Engineer magazine concerning this subject. I'll check tomorrow and see if I can find it.

Bill Russell

Chris Maderia

Sizing

Self-Service laundries typically require 2 1/2 gallons of water per pound of laundry, which should be adequate for hot water storage plus a recovery capacity equal to the hourly demand of automatic washing machines. Commercial laundry require typically 3 gallons of hot water per one pound of laundry with half the required water being hot.

Use a calculation of two cycles per hour. This, multiplied by the number of machines by the gallon of hot water used by each machine, gives the amount of hot water used per hour. This known GPH, along with temperature of water required, will determine the capacity needed.

Hot water requirements for a self-service laundry are determined through the following steps:

1. From the rating plate on the machine or from the manufacturer's literature, find hot water usage in GPH for each washer.

A. Few slef-service laundries use the pre-wash soak cycle. This factor should be ascertainined, however and the gallonage used in the soak cycle subtracted from the unit rating.

B. If the rating for each washer cannot be found, use 26 GPH for each unit (if 1 cycle per hour).

2. Add together all the individual washer requirements for the maximum load hourly demand.

This formula is for average conditions which include an occasional peak demand. When all machines are used constantly, the rpeceding formula must be doubled.

Now this will give you a good idea for where you stand but I would recommend that you speak with whomever you plan on getting your equipment from and have them size this for you.

JackFre

Laundromat

First the disclaimer. I represent Rinnai in the New England territory. We've been doing a bunch of laundromats around NE with the Rinnai Continuum Model 2532 FFU-C. Sizing guidelines are at Rinnai.us.com. Did one in Lewiston ME with 4 units. Full on demand system, no storage. With the room saved over the conventional system we replaced, the owner put in an office and store room. Pretty cool. We have used 4 units on smaller systems and up to six (2 banks of 3)on larger l-mats. From the sizing guidline you can see that poundage of the machines is a must for complete sizing. We have six of these systems operating that I am aware of and they are operating very well and efficiently. Direct Vent so no make-up air issues. Tons of data on the web site. Happy Holidays

Bill_14

What is your fax number? (nm)

Jackchips

Does your company

do the sizing and guarantee to meet the load, Jack. Interesting stuff. I would be interested in a copy of your design literature.