Sizing Module Parameters-

When you entered you zip code we set two variables:

-Entering water temperature (EWT). We set EWT based on information from the United States Geological Survey. This is the statewide ground water temperature for your state. EWT can vary significantly based on your water source so you should carefully consider this factor, as it will significantly impact sizing calculations.

-Elevation. We utilize a database of the elevation for your local post office. Above 3000' above sea level system capacity drops with increased elevation. We adjust capacity based our database altitude. If the elevation for your application is substantially different than that displayed adjust this factor to provide precise sizing.

General Sizing Guidelines-

Diversity: We have utilized the general sizing guidelines published in the American Society of Plumbing Engineers second addition. An important issue to consider with sizing domestic hot water equipment is the diversity factor. This represents the percentage of available for water equipment that is operating at only one time. In general the load factor used in this calculator is .65. In other words we are assuming that only 65% of the available hot water consuming appliances will be calling at any on time. If your application will require sustained flow rates above 65% then you MUST increase the hot water system output capacity.

Use Temperature (POU): Unless otherwise noted we use 108� F as the use temperature. If you will be utilizing other temperature water you must change this default.

Specific Sizing Guidelines-

Residential: (Based on HUD and FHA Minimum Water Heater Capacities)

Baths: GPH

1 - 1.5 Baths 60

2 - 2.5 Baths 72

3 - 3.5 Baths 90

4 - 4.5 Baths 152

Additional Baths 20 GPH Each

Large Tubs (above 60 gals capacity): 0.8 GPH x Tube Capacity

High Flow Shower Heads: Net GPM Flow Rate (no diversity)

Multi-Family Residential: (Based on 1999 ASHREA Applications Handbook)

Apartment Units GPH Per Unit

6 Units and Under:

1 - 1.5 Baths 60

2 - 2.5 Baths 72

3 - 3.5 Baths 90

More Than 5 Units:

One Bedroom - 2 occupants 13.2

Two Bedroom - 3 occupants 19.8

Three Bedroom - 5 occupants 29.1

Penthouse with 2 Suites 39.6

Laundry:

Coin Op 18.5 GPH per Machine

Commercial 3.0 GPH / Lbs Capacity

Hotel - Motel:

Unit Type GPH / Unit

Business - Convention 32

4 & 5 Star Vacation Resort 18

3 Star Accommodation 12

Extended Care Facilities:

Assisted Living Units GPH / Unit

1 Bedroom Unit 13.2

2 Bedroom Unit 19.8

Nursing Home Care 9.2 / Bed

Hospital:

Appliance: GPH / Fixture

Lavatory 8.0

Shower 30.0

Kitchen or Service Sink 20.0

Whirlpool Tub 0.8 x Capacity (gal)

Hydrotherapeutic Shower 400.0

Leg Bath 100.0

Arm or Sitz Bath 25.0

Restaurants:

Dishwashers: We have loaded all current NSF rated model dishwashers. The maximum output temperature for Eternal water heaters is 167� F so if you are using a hot water sterilizing rinse you MUST still use a booster. Dishwashers are calculated at 100% load without a diversity factor.

Appliance GPH / Fixture

Vegetable Sink 45.0

Single Pot Sink 30.0

Double Pot Sink 60.0

Triple Pot Sink 90.0

Prescrapper (open) 180.0

Hand Operated Pre-wash 45.0

Closed Pre-wash 240.0

Recalculating Pre-wash 40.0

Wash Basin or Bar Sink 30.0

Lavatory 5.0