We are building an addition to our home. It the space will be used primarily by guests. my question is: Should we consider have an Instant Hot Water system for that portion of the house? Ther will be weeks at a time when the water will not be turned on and keeoing a regular hot water heater seems a waste of electricity?
The principle of instantaneous is great when the usage is low as you are proposing but it depends what part of the world you are in. If you are considering electric intantaneous then it is unlikely that you will achieve satisfactory flow rates at the shower. If you are using gas then ok. However both depend on the water temperature coming in to the house especially if you are in a cold climate. Instantaneous systems only have a fixed energy input therefore the water flow passing over the burner/element needs to be controlled to get the desired temperature. My suuestion is to contact your local supplier and find out what system is correct for you.
Buy a Rinnai gas instantaneous (tank less ) and a model with a 20 litre/minute will suffice for your needs – best to have one with a remote controller fitted to suit the bathroom – they are optional extras.
Selgas Services Ltd Craftsman Gasfitters, Plumbers, Electrical Service Technicians