Which water heater?

[Cr0ntab]

I'm looking into purchasing a new water heater to replace our 21 year old 50 gallon A.O. smith.

I've narrowed it down to two that are available at home depot.

Rheem 80 Gallon Hybrid Heat Pump
Model: XE80T10HD50U1
First Hour Rating: 89 Gallons
90* Recovery: 29 GPH
Energy Guide Yearly Usage: 1341 kWh

Westinghouse (HTP rebranded) 50 Gallon 76k BTU condensing
Model: WGR050NG076
First Hour Rating: 154 Gallons
90* Recovery: 98 GPH
Energy Guide Yearly Usage: 188 Therms

I live in Southern California and the water heater will be placed in the garage with plenty of space and plenty of ambient heat.

My natural gas price works out to be $1.018/therm which puts the Westinghouse at an estimated $191.38 per year to run.

My electric is at $0.220/kWh however next week I'm starting the installation of my solar array with enough power to cover the Rheem's usage so power should essentially be "free"

Now, I have a family of 4.

The home has 3 full baths with 2gpm shower heads.

We mainly take showers and I would like the ability to do 2 concurrent showers back to back (4 total), with the showering time averaging 10 minutes.

If my math is correct that's ~80 gallons in the first hour (10 minutes x 2 gpm x 4 showers).

I like that the Rheem will essentially be cost free due to my solar and would pay itself back (at my electrical rates) within the warranty. But I question whether or not it can meet the demand. It has an 89 gallon FHR which technically should be just enough to cover the showering. However it feels like it's cutting it close and the 29GPH recovery seems rather dismal. Also, the anode replacement is a slight turn off, but not a deal breaker.

I like the Westinghouse because it's like the perfect hybrid between tank and tankless. High output burner that modulates that should provide plenty of hot water. Gas is already plumbed in so I wouldn't need to change much there. I like that the unit is a stainless steel tank which means very little maintenance long term.

We originally looked at tankless for the "endless hot water" but didn't like all the complexity required to get the "instant" hot water with our existing plumbing layout (no recirculation lines, we're using the thermostatic valves).

I'm definitely leaning towards the Westinghouse gas fired, but just curious to see from the group if i'm missing anything in my analysis.

P.S. A drain water heat recovery system isn't in the cards right now, but I'll probably look into that in the future.

 

[pcunite]

You're on the right track. I've done a lot of research in this area but still learning. Look at these models (some are the same hardware but with different branding & pricing). Basically, all you need to care about is Recovery GPH*. Get the highest you can afford that still meets your demands. A 10 minute shower is not realistic for my family. If your budget is $2,000, then consider the HTP Crossover RGH20-100 (aka Westinghouse WGRGH20NG100F) or the PG10-34-100-2NV.

• Polaris GSP-100
• American Water PG10-34-100-2NV
• HTP Crossover RGH20-100
• Westinghouse WGRGH20NG100F
• HTP Phoenix PH76-50
• Westinghouse WGR050NG076

* The only time ongoing Recovery GPH fails to guide you is say when you want to fill a 120 gal jacuzzi. The nozzle might be a 5gpm and thus you can empty a 50 gal tank faster than the Recovery GPH can catch up. In that instance First Hour Rating is a helpful metric. But at what gpm? Ahhh, the catch! What if you could output 10gpm, how fast could the heater keep up then? So, while Recovery GPH is what we all should be looking at ... it is still a measure of the total continuous gpm occurring at a moment in time.