"Point of Use" or "Whole House Tankless"?

[Izabella]

I am renovating a new one bedroom, one bathroom home. It is 900 square feet in size, so space is at a premium. It means we won't be able to use the conventional big tank heater. Because we don't have gas, we'll need electricity ...and one Whole House Tankless or three Point of Use heaters in the kitchen, one in the bathroom, and one in the laundry. The washer is only a couple of feet from the bathroom heater which means.....maybe this third heater isn't needed for the laundry. ???



However, the budget is a serious consideration. That said, I am not a big fan of running water, waiting for it to get hot... but it's not a deal breaker if it means saving a lot of money.



I have my kitchen, the bath 20' from there, then the laundry washer another 12' away from it. If it helps/matters, the largest gap between my plumbing is 32'.



Could you please tell me what you would recommend in my case? Two or three Point of Use heaters......OR a whole house tankless heater in the bathroom? I am badly confused and unable to take decision.

 

[Breplum]

How much electrical power is available is one factor. Then running dedicated power lines to each spot and dealing with piping at each fixture is another cost factor.
If you are not doing all the work yourself, you should just get pros to price for you and base everything on that.
You are going to be factoring your local water temp., plus temperature rise based on flow.
Note that cheaper electrical instant water heaters (EEMAX and do not necessarily last that long and only come with a one year parts warranty, so buy a spare!
Stiebel Eltron tankless have 3 year warranties and cost double.

 

[Sponsor]

 

[Izabella]

Thanks,

 

[Izabella]

Yes, warranties are important to consider. I am looking into it.

 

[Fitter30]

Have do some homework. Whats the coldest water temp, the hottest and gpm for faucets, shower, tub, dishwasher and clothes washer. Point of use is ok for a faucet not so much for larger usage plus the electric might have enough open breaker slots for muilti units, Here is a link for mixed hot water temp to cold just change settings to gpm.
https://www.spiraxsarco.com/resources-and-design-tools/calculators/water-mixing/water-mixing

 

[Izabella]

Have do some homework. Whats the coldest water temp, the hottest and gpm for faucets, shower, tub, dishwasher and clothes washer. Point of use is ok for a faucet not so much for larger usage plus the electric might have enough open breaker slots for muilti units, Here is a link for mixed hot water temp to cold just change settings to gpm.
https://www.spiraxsarco.com/resources-and-design-tools/calculators/water-mixing/water-mixing

thank you I check this

 

[Jadnashua]

It is highly unlikely that you have a big enough electrical service to run three tankless systems. And, because they all could be on at the same time, your peak power rating could be huge. Some utilities charge a demand charge, which, while you may not use it all that often, can mean your base rate for electricity will go up during the electrical service upgrade likely needed.

IMHO, your better choice would be maybe a bigger tank and add a recirculation system. Especially on the new work, you could insulate the lines. A properly implemented recirculation system will give you essentially instant hot water at the outlets it supports.

One thing that hits some people with a tankless system is the minimum flow rate to enable it to turn on...way you've got the sink (which will have a flow restricted valve by code) turned to what should be a warm position, on many tankless systems, that isn't enough flow to turn them on at all. A workaround on some is to use full hot, then, move it to warm, as the turn off can be smaller than the turn on volume. Low flow and warm may never keep the tankless turned on. Chicago probably gets a lot of its water from the lake, so unless you have a softener, you'll be introducing at least an annual service call on each unit to descale it, or the performance will quickly degrade.

Tankless systems can work well, but are harder to specify and setup in areas where the ground water temperature gets quite cold, and will require regular maintenance to keep them running although especially on an electric one, they're pretty simple. Not as simple as an electric tank, though!

If a bathroom includes a tub, an electric tankless system will usually be quickly overwhelmed, and may never work, nor would it if you had a multihead shower during the wintertime.

If you're willing and able, you might get by with propane units, but I still think a (maybe larger) electric tank and a recirculation system would fit the bill better.

 

[Izabella]

Thank you everyone, I bought 24 kw Rheem with the flow rate 5.9. I hope it would be a best decision. It has 5 years warranty.