changing Indirect H/W Boiler to Cold start

Kaos

https://forum.heatinghelp.com/discussion/comment/1894439#Comment_1894439

The issues were with HPWH installed in very small spaces, this is still an issue with current installation recommendations. We are talking about the typical open basement here.

That math is missing a lot of bits. You get heat transfer from all the surfaces including heat from the upper floor. From the study:

"no detectable lasting impact on foundation surface temperatures"

"air temperatures did return to comparable temperatures to the control house basement"

Unsurprisingly, running a very small water source AC in a relatively large space does nothing.

pedmec

Everything that has been hyped about heat pumps, heat or hot water, has been coming back as false. Everyday day real life customers complain about there heat pump mini splits and wish they have never put them in. They can't stand the cool dry air coming off the coil. It's like meeting the hottest chick at the party to realize she dumb as a box of rocks, has no job, and no direction in life. That's a heat pump mini split or water heater. They might have a place in the south but up here in the northeast customers complain about high electricity bills. And never mind when you have a mini split with a small refrigerant leak. By the time you realize its a leak the electric bill is so high you could have did a whole replacement.

ethicalpaul

Respectfully, Roger, that is a lot of panic-baiting. It sits in my basement and heats my water without bothering anybody or anything and certainly isn't causing any condensation or mold…in fact it removes moisture from my basement in the summer, as you probably know.

pedmec

@ethicalpaul Just curious, did you install a drain for your HPWH?

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1894446#Comment_1894446

It stands next to my slop sink and I ran a line that drains into that.

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1894443#Comment_1894443

I think you are conflating mini split concerns with heat pump concerns. They don't overlap.

pedmec

Not really. My comment concerns the money saving aspect from installing heat pump systems, whether heat or hot water. Due to conditions that the heat pump can't control they are not as efficient as advertised. But that's not the only issue. It's turning that the claims from the manufacturers have not been truthful and that they have been fudging the numbers. The articles are coming out. Heat pump water heaters failure rates are huge. and when the compressor fails you wind up running it in electric heat anyway.

And trust me, i don't care either way. whether it's fossil fuel, electric, or solar. i just want something that works and is reliable.

I just think you way overstating the heat pump water heater and can't stand the thought of an indirect, which in my estimation is far superior. I mean, seriously, is it in the end all about being comfortable. Out of site and out of mind. I don't get that from a heat pump water heater. I think the heat pump compressor failure is due to oil return. The basements that i've been in have really gotten cold. I work in the city a lot. Small basements

ethicalpaul

Heat pump water heaters failure rates are huge

What is the failure rate?

EBEBRATT-Ed

I don't know but I have too respectfully disagree with what @EdTheHeaterMan posted about electric HW heaters.

a 40 gallon electric wh= 40x 8.33=333 pounds of water from 58 to 120 degrees will need 20646 btus not including any jacket loss.

a 4500 watt element is 100% efficient and produces 3.42 btu/watt so in 1 hour =15390btu.

So it would take 80 min to heat a cold tank to 120 not including jacket loss.

Certainly not going to take 4 hours.

EdTheHeaterMan

https://forum.heatinghelp.com/discussion/comment/1894453#Comment_1894453

The math makes sense @EBEBRATT-Ed, I just did the timing on a water heater that I installed one morning and filled it with cold tap water thru the meter. Then I turned on the switch and made note of the time. I kept looking at the meter after 2 hours and it was still spinning rapidly, so I knew that the elements were using the power. No one was home at the time so there was not AC or cooking to account for the meter spinning fast. I was there the entire day installing an AC unit with new lineset and air handler. It was a full 8+ hour day. It took more that 3h 57 min. Perhaps it was a larger gallon tank, I just remember the amount of time surprised me. This was back in the 1989-1990 era. That is when I remember having that info in a sales book I carried with me to sell new equipment. I even had the customer's address for each of the 4 different water heaters I installed to make the data believable. I can remember what the page looked like with the graph diagram next to each picture of a water heater.

If it was 4 hours then perhaps it was an 80 gallon tank. Some people with electric water heaters needed something larger. Thats because the 40 gallon tank ran out too soon for the average teenage daughter. Now that I am over the hill, my memory may be off a few gallons. But the time was what I remember clearly. I wish i still had that sales book with lots of information. My kids woild like to see that stuff today.

I remember finding my dad's sales kit for signing up new oil heat customers in the 1950's where there was a story about a gas explosion in 1947, and resulting fire in Conshohocken, Pa. about 20 miles west of Philadelphia. Everyone knew about it, it was BIG NEWS. There was the news paper article about the explosion in a clear plastic photo album covered page, and a picture of a fire cracker exploding with the caption "Go Modern, Go Gas, Go Boom!" in the back pages of the book. Funny thing was that Conshohocken had another bigger explosion in 1971. Seems that Oil Heat was safer in the days of OLD Natural Gas pipelines. Some folks would not live on a street where there was a gas pipeline in the ground. He and his three brothers signed up lots of oil heat customers in the 1950s and 60s. Over 5000 automatic delivery oil accounts with service contracts.

Roger

Thank you, @ethicalpaul - the article's authors are very well versed and are very broadly recognized as top experts in HVAC and HPWH technology. The article primarily addresses lessons learned from the past decade of installation, and it concludes:

We ensure that gas and electric water heater installations can safely make hot water 24 hours a day, if needed; why would we limit the ability of HPWHs to do the same? HPWHs offer unprecedented water heating efficiency but they must be thoughtfully designed and installed to achieve their potential without causing harm to buildings or their occupants.

EBEBRATT-Ed

Some electric WH are available now with 5kw elements instead of the usual 4.5kw. Gives you an xtra 1710 btu/hour enough to heat 3 additional gallons of water from 50-120.

Not much. But 5000/240volt is 21 amps so it will still run on the usual 30 amp circuit.