Experienced with Heat Pump Water Heaters?
Anyone experienced with HPWH??
Costing from $700-$1,500, these systems may be a great way to reduce humidity while generating inexpensive hot water. If they are tied to the AC return it could reduce the AC load requirements. Manufacturers claim HPWH have the highest ROI compared to other alternatives. A whole house dehumidifier costs 500-$2,000. A solar hot water heater costs upwards of $3,000. Hot water generation represents 20-30% of a family's energy bill.
I seen negative posts on these systems but few responses with actual experience working with them.
For additional info check these links:
US Dept of Energy
They've never caught on.
In theory, a splendid way to heat water at 1/4 - 1/2 the cost of resistance electric.
In reality, it'll only work in a niche situation: One needs a large open basement or garage in a warm climate. Put one in a new england or upper midwest house and it'll likely be a disaster.
Even in a warm climate, the garage or basement, already cold and damp in winter, would become more so with one of these installed.
Were I to deploy one, I'd consider it in a pre / tempering tank arragement with either manual control or a lockout based on ambient temperature - no run below 60-70 degrees or so.
Payback would be a long time (many many years) unless electric rate or hot water use was very high.
"Even in a warm climate, the garage or basement, already cold and damp in winter, would become more so with one of these installed."
I can understand cold but damp? I need a whole house dehumidifier. Why can't I plumb one of these into my house duct work generate hot water plus reduce moister in the house? In the summer it reduces my AC load, in the winter I could damper it outside.
This is all good stuff. A family of four (65 gals./day) spend $300-$500 per year to heat water. The best HPWH could do this for $250. Investment, maintainence, and repair are significant. The range of product that was available during the last energy crunch varied from "swiss watch to junk". If any needed major repair, techs were not enterested, profiteers, and unable. As a manufacturer of one of the original "swiss watches" HPWH (3.5 cop), we never made any profit. Many are still operating, +20 years old. When utility rebates stoped, the bussiness slowed. One continuied success is the Therma-Stor heat recovery tanks(shown on the website). They heat 90% of all the hot water in the supermarkets/dairy farms in the U.S. We manufacture thousands every year. The recovery tanks shared heat transfer/tank technology our hpwh. For kicks, I integrated a Santa Fe whole house dehumidifier with a heat recovery tank in R&D. The combination worked well. Ventilation, humidity control, and hot water for 50-70% less with a +$3,000 investment. I could not imagine profitably marketing, installing, and servicing for the typical market. How would a typical tech respond to the inevitable service call 7-12 years from installation? "I do not work on those" or a $1000 sevice call. Used to be a hpwh TB
Originally Posted by downtown
another source of information
one possible source for home systems
This is a subject I am VERY interested in. I plan on incorporating a HPWH in my own house - starting construction soon.
I believe that a $300 tax credit is possible if purchased this year.
I was quite unhappy when I found out that Thermastor had stopped making them.
the only experienced user I have found so far
I am discourage!
With Thermostor out of the business does not look too good. You would think they would have closely looked at this technology for their UltraAire product line
The link you provided for the user experience discussion gets lost in the frame. Please resubmit or paste the highlights inside a new post.
I am discourage! I am surprised no one can recommend HPWH. I need to purchase a DHW heater plus humidifier. I know the humidifier is costly to run.
experience from other user
"I don't use my HPWH until we're consistently over 70º. But I'm no expert and there may be a HPWH that likes cooler temps than mine does. There was a great gov't site on them, but it disappeared. Best I've since found is http://www.energy.wsu.edu/ftp-ep/pub...water_htrs.pdf
Our HPWH is plumbed into our standard elec tank heater, keeping the elements from being turned on. I was looking for roughly 1/3 elec consumption when I bought it. Big surprise was the volume of dehumidified air. When the two of us are home, gives us half the dehumidification we need for our 20,000 cu ft with .5 ACH in a humid climate.
Oh, if your water heater has electronic controls (Lowe's best), my HPWH won't work automatically with it. The non-electronic models work great. Uses the tank thermostats to turn on and off the HPWH. Mine's an E.tech from Crispaire Corp in Cordele, Ga. If/when it dies, I'm immediately getting another one. This one was new-old stock (no warranty) on ebay, paid for itself in just over one season. I'm getting cheap water heating and free dehumidification. If your basement's warm enough and you have air circulation, jump on one.
I picked up a tankless HPWH on ebay for a small fraction of normal cost. It's an E Tech WH-6B. Works like a dream with a std electric tank heater. Wall hung and requires a drain line. Byproduct is cool dry air, which in our humid, normally AC, climate is fantastic. Doesn't work very well below 70º so we only use it when we have excess heat. Unfortunately I replaced our std tank heater recently with a Lowe's Whirlpool with electronic control. It's a mismatch, requiring me to figure out some odd wiring. Neither E Tech nor Whirlpool could figure out how to get them to work together. What I did isn't great, but it works.
During our first 6 months of operation we saw enough electricity savings to pay for the unit. Plus getting the dehumidification and cooling free. With current normal pricing that would traslate closer to 4 summers. You'd have to have the correct house design for one to work properly. We did. "
You could also heat your water by burning logs under a water tank.
No matter how much you save, an HPWH or desuperheater tank is NOT going to produce water as hot as a true electric tank.
You like mild showers? Help yourself.
Good? Bad? I'm the guy with the gun.
Statements made by me are strictly my opinions and do not reflect the opinions of my employer. I am not authorized to make any official statements on behalf of my employer.
Any technical advice offered by me is for educational purposes only, all HVAC related repairs should only be attempted by qualified personnel.
the theme is not to just use this to heat water, but to temper it before going into the HWH --
this was a leading article in a building design magazine -- of using loops in wells to temper water to HWH -- commercial bldg -- quick payback
harvest rainwater,make SHADE,R75/50/30= roof/wall/floor, use HVAC mastic,caulk all wall seams!
Please, keep your comments to things you know about. Good heat pump water heaters produce 135^F hot water. I have a Therma-Stor 1985 with the backup element disconnected. Raised four kids and seldom ran low on hot water. 21 years old and I dread the day it quits. The Therma-Stor tanks used in most of modern day supermarkets heat 95% of their hot water. Not mad, only disapointed.
Originally Posted by dougfamous
In summary, it seems that for the right application HPWH are effective for reducing electricity costs for heating hot water while reducing humidity. If you had to buy a new HPWH right now what would it be?
Heatpump water heater
We have installed several units in commerical Kitchens. They work well for preheating the water. Also help with the cooling load. Customer was a little gun shy the first time. The first one ran for about amnoth or two and the customer wanted several others installes ASAP.
What was the brand you installed in the kitchens?