How To: Choose the Right Sized Hot Water System for Your Home
August 4, 2016
“A solar hot water system should be sized to suit the home, as well as the occupants. A 22 Tube, 250L system may suit a couple – but in a 3 bedroom home and with a family on the way, it may struggle in the future! Below is a quick sizing guide to follow as a rule of thumb”.
1-3 Bedroom Home (Small)
This size home is what we classify a “Small” home. In most regions, a 20 Tube 250 Litre system is sufficient for this sized home. However in the colder regions of Australia – some consumers opt for a 30 Tube 250 Litre system to give them maximum output.
3-4 Bedroom Home (Medium)
The standard Aussie home is the 3-4 bedroom and what we classify as a “Medium” home. The ideal unit for this size is a generally a 30 Tube, 315 Litre system. The Apricus 30 Tube, 315 Litre system will handle a family of 4-5 due to the extra storage.
5+ Bedroom Home (Large)
5+ Bedrooms are classified as “Large” homes, and generally a 40 Tube, 400 Litre system is required for this size home. As a 30 Tube is the largest single manifold that Apricus manufacture, when going to this size 2 x 20 Tube manifolds are used and connected together.
CHOOSING THE BOOSTER
“Selecting the correct booster is just as important for a solar hot water system as the sizing of the collector and storage tank. Inefficient boosting can result in wasted energy and higher running costs for the consumer.”
Below are some tips to choose the right booster for your customer, as well as provide advice on the best way to power the booster to suit their needs.
- Middle (MID) element:
The electric boosting element is located approximately 1/3 to 1/2 way up the wall of the storage tank, which reduces the amount of energy the system will use when boosting. (for example – in a 315L tank, the booster may only heat 200L of water) – These systems are most popular for smaller families, or in the warmer regions of Australia.
- Bottom (BOT) element:
The electric boosting element is closer to the bottom of the storage tank. This will result in increased energy usage when booster is in use, but will result in a greater volume of the tank being heated and available for use. Bottom element tanks are most popular in cold regions or in installations where larger volumes of hot water are required (e.g. VIC/TAS and homes with large families)
The biggest benefit of gas boosting is the household will receive virtually unlimited supply of hot water, as gas boosting is done by a continuous flow gas heater.
The Apricus gas boosters are generally a good choice if the home has natural gas or LPG gas connected for cooking and other appliances. Gas boosters will start only when heating is required, however it is worth explaining to the consumer that if the water in the pipes between the tank and booster goes cold, it may start up for a short period and then switch back off.
POWERING THE ELECTRIC BOOSTER
The main benefit of off peak is the lower cost, however if the household showers at night they will drain the tank, off peak will heat overnight and in the morning when the sun comes out no heat is required.
Electric timer (peak)
Using peak power may be at a higher rate, but when set for 4-6pm daily, it allows the solar to heat as much as possible from the sunshine and any extra heating required is done by electricity prior to evening showers. (Remember the booster will only turn on if water is below 65°C, and will switch off as soon as 65°C is reached).