Tips for Water Heater Sizing

There are no hard and fast rules to determine the best size and type of water heater for your application. Water heaters are classified according to several factors, whether for private of commercial use. The Vancouver Water Heaters experts at High Mark Plumbing can help you decide which water heater will best suit your needs.

The primary concern when sizing a new water heater is occupancy of the building. Other important factors include:

  • Recovery Rate – is how much water can be heated in one hour. Typically, and electric water heater (storage type) can heat approximately 15-20 gallons per hour. Gas and oil fired water heaters generally have higher recovery rates than electric. Every water heater will list in its specifications the expected recovery rate.
  • Future Needs – a standard (storage) water heater has an average life of about 10 years. If you expect to have children or have parents move in with you in the next several years, it is advised that you include them in the occupancy totals. Sizing for realistic expectations is recommended, although, oversizing can cost money in energy to heat the additional water.
  • Women vs. Men – not a sexist factor, but women do, in fact, spend an average of 30% longer in the shower than men. This most definitely should be taken into account when sizing a new water heater! Remember: when mommy (wife, mother, daughter, etc.) is happy – everyone is happy! You do not want her running out of hot water on a daily basis while showering, now, do you?
  • Age Consideration – remember that with young children comes repeated washings throughout the day and increased laundry needs. Increase you water heater size accordingly.
  • Water Fixtures – large tubs, hot tubs, jacuzzis all require large amounts of hot water. Often, it is advisable to purchase a dedicated water heater for such specialty installations. Vancouver Tankless water heaters are a perfect option as the dedicated system for any specialty fixture.
  • Piping – determining the minimum required outlet piping is necessary. For outlet piping in excess of 3/4″, you will need a commercial water heater. Alternatively, to meet the demands of a larger outlet pipe, you can connect multiple residential water heaters in series.

Residential Sizing 

Taking into consideration the additional factors listed above, the following table is a rough guide for residential water heater size:

Please note: the minimum capacity for a home with one whirlpool tub is 60 – 80 gallons. Remember to include any additional factors when choosing the best water heater for your home. The Vancouver Plumbing and Water Heater Supply experts at High Mark Plumbing can perform a complete hot water audit on your home to assure you choose the perfect water heater to meet all you needs.

Considerations for Commercial Water Heaters

Commercial water heaters are sized according to business type, building size and type, and occupancy. For example, a laundromat will use copious amounts of hot water as compared to an office building or library. Likewise, an apartment building must take into account whether there are children, pets, and specialty water fixtures (as indicated in sizing factors, above). Generally, the starting point for sizing commercial water heaters use predetermined statistics for each business type.