How to Calculate Hot Water Supply for a House?

In summary, the conversation discusses the calculation of hot water needed for a house according to a design brief. This includes delivering 15 gallons of water at an average temperature of 110°F within 10 minutes for 16 water draws in a week, as well as successfully washing five loads of dishes in a week. The terms "draws" and "loads" refer to the amount of water used for each activity, with 16 draws equaling 240 gallons and five loads equaling 75 gallons. However, further information is needed to accurately answer the questions posed in the conversation.
  • #1
Weicheng
1
0
HI i am a student from Singapore , and i was told to calculate the amount of hot water needed to supply to a house. The design brief stated
1)Deliver 15 gallons of water at average 110°F (43°C) temperature within 10 minutes; 16 water draws during 1 week
2)Dishwasher: Successfully wash five loads of dishes during 1 week

Whats does this specs means? 16 draws means 15 gallons X 16 in a week? also for dishwasher what does it means 5 loads?How do i know how many gallons would it use? Our lecturer had not idea and only asked us look online. I hope you guys could help us. Our rough idea is just solar thermal panels( compulsary thermal instead of PV) , maybe 2-3 panels and a tank. Tank sizing is a porblem too.
 
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  • #2
A "load" refers to the act of loading the dishwasher and then using it. It is the same as "doing a load of laundry"/

So 5 loads means five uses of the dishwasher.
 
  • #3
To "draw water" is a term not used often. Most commonly, people will say "I'm going to draw a bath" meaning they will fill the tub with water.

So I would say that 16 "water draws" means 16 uses.
 
  • #4
Are questions 1 & 2 both referring to a dishwasher?

Could you post the full question?My guess is this:

1: every "draw" or use is 15 gallons. 16 uses is 16*15 = 240 gallons needed that week.

2: if the dishwasher uses 15 gallons per use, 10 minutes long... 5 loads will be 5* 15 or 75 gallons.

I don't think we have enough information from you to answer the questions properly though.
 

FAQ: How to Calculate Hot Water Supply for a House?

1. How do you calculate the required hot water supply for a building?

To calculate the required hot water supply for a building, you need to determine the total demand for hot water. This can be done by estimating the number of people using the hot water, the duration of hot water use, and the flow rate of fixtures. With this information, you can use a formula to determine the required volume of hot water storage for the building.

2. What factors should be considered when calculating hot water supply?

When calculating hot water supply, you should consider the number of people using hot water, the number and types of fixtures, the flow rates of the fixtures, the temperature rise needed, and the time of day when hot water demand is highest. Other factors such as the type of fuel used and the efficiency of the water heater should also be taken into account.

3. How do you determine the temperature rise needed for hot water supply?

The temperature rise needed for hot water supply can be determined by subtracting the cold water temperature from the desired hot water temperature. In most cases, a temperature rise of 20-30 degrees Fahrenheit is sufficient for residential buildings, while commercial buildings may require a higher temperature rise.

4. What is the difference between instant (tankless) and storage water heaters for hot water supply?

Instant or tankless water heaters heat water on demand, providing hot water as needed. Storage water heaters, on the other hand, store hot water in a tank and continuously heat it to maintain a desired temperature. Instant water heaters are more energy-efficient but have a limited flow rate, while storage water heaters have a larger storage capacity and can provide hot water for multiple fixtures simultaneously.

5. How can energy conservation be incorporated into hot water supply calculations?

Energy conservation can be incorporated into hot water supply calculations by using energy-efficient fixtures and appliances, installing insulation on hot water pipes, and using a high-efficiency water heater. It is also important to regularly maintain the hot water system to ensure it is functioning optimally and not wasting energy.

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