Energy recovery

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Ashful

Minister of Fire
Mar 7, 2012
19,973
Philadelphia
Thread hijack moved to new thread.

Yeah, good point.

I usually think about refrigerators this time of year. It bothers me that it runs to exchange heat indoors where it's 70 degrees when its 30 degrees outside.
Probably not as big a deal, as the wasted energy is going toward heating your home, so the actual "loss" is zero during heating season. That "waste", if you can even call it that after reclamation against your heat demand, is probably relatively low given the heat pump efficiency.
 
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And yes, whenever our dryer kicks it I plan to replace it with a heat pump one. But our budget line whirlpool electric dryer is only ~10 years old and seems to have plenty of life in it. We have a 1985 Maytag washer that is also going strong, just got new belts a year ago.
Between refrigerators, home AC, minisplits, dehumidifiers, and a pool heater, I guess I have 13 heat pumps running in this house (that I can remember). The trouble is, all of those which are installed in portable appliances have horrendously bad reliability. I average 2 - 3 years per dehumidifier, and about the same on refrigerators. Do you really want to be replacing clothes dryers with similar frequency?

Heat pumps can be reliable, one of my largest AC units is near 40 years old, but the cheap ones included in appliances seem to have horrendously bad reliability. Being disposable rather than repairable, this translates to short appliance lifetimes, as noted in my recent "EPA shortsighted" thread about the death of another one of my 2-year old refrigerators.
 
It’s too bad that they don’t have outside air kits. Taking cold air from outside and heating it would really lower the relative humidity of that air. That could really increase the speed of the drying and lower fuel usage. It seems like it’d be an easy thing to incorporate into a design too!
During the winter, I disconnect my dryer hose and route it through a filter box. Warm humid air rises into our living space from our partially finished basement. I dont know why I havent thought of this before honestly.
 
Between refrigerators, home AC, minisplits, dehumidifiers, and a pool heater, I guess I have 13 heat pumps running in this house (that I can remember). The trouble is, all of those which are installed in portable appliances have horrendously bad reliability. I average 2 - 3 years per dehumidifier, and about the same on refrigerators. Do you really want to be replacing clothes dryers with similar frequency?

Heat pumps can be reliable, one of my largest AC units is near 40 years old, but the cheap ones included in appliances seem to have horrendously bad reliability. Being disposable rather than repairable, this translates to short appliance lifetimes, as noted in my recent "EPA shortsighted" thread about the death of another one of my 2-year old refrigerators.
This connects to my general view on replacing appliances. Reliability has gone way down, not just for heat pumps, and I would much rather keep an old appliance going than replace it and begin the 2-year junk cycle. I'm not sure if a new non-heatpump dryer would last any longer. They all have control boards that die and get discontinued rendering it a brick.. That's why I said "when my dryer kicks it." I will not replace any pre-2010 appliance if there's any hope of repairing it.

Side note... as I think I commented in the other thread, or maybe I just thought it.. this has nothing to do with EPA regulations. Just good ol' corporate bottom lines pushing manufacturers to cheap out in every way possible. I'd be curious to see how something like a mandatory 15-year warranty would change those calculations...
 
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Between refrigerators, home AC, minisplits, dehumidifiers, and a pool heater, I guess I have 13 heat pumps running in this house (that I can remember). The trouble is, all of those which are installed in portable appliances have horrendously bad reliability. I average 2 - 3 years per dehumidifier, and about the same on refrigerators. Do you really want to be replacing clothes dryers with similar frequency?

Heat pumps can be reliable, one of my largest AC units is near 40 years old, but the cheap ones included in appliances seem to have horrendously bad reliability. Being disposable rather than repairable, this translates to short appliance lifetimes, as noted in my recent "EPA shortsighted" thread about the death of another one of my 2-year old refrigerators.
One day we need to see a room by room tour of this mansion. Housing prices have gone insane. 800k here, 4 bedroom with a garage that can only fit one car on 4 acres with a cheap waterfall in the front yard, overlooking a junk yard. Interior is filled with cheap flooring, fake brick, big open cold spaces with no character, and large windows haphazardly placed for the 'wow' factor of a perspective buyer. There's no wood detail, no real materials used that matter. And worse, the siding is all plastic not wood or brick. Sigh.
 
This connects to my general view on replacing appliances. Reliability has gone way down, not just for heat pumps, and I would much rather keep an old appliance going than replace it and begin the 2-year junk cycle. I'm not sure if a new non-heatpump dryer would last any longer. They all have control boards that die and get discontinued rendering it a brick.. That's why I said "when my dryer kicks it." I will not replace any pre-2010 appliance if there's any hope of repairing it.
I used to believe in the last few years that maytag and whirlpool were junk, then I realized that the only game occuring to avoid being at the bottom or to have a product that just doesnt work at all new from the store.
 
And yes, whenever our dryer kicks it I plan to replace it with a heat pump one. But our budget line whirlpool electric dryer is only ~10 years old and seems to have plenty of life in it. We have a 1985 Maytag washer that is also going strong, just got new belts a year ago.
My issue is size right now. With 5 kids I need the biggest capacity I can get IF I use the drier. Todays load will get hung out.
 
I used to believe in the last few years that maytag and whirlpool were junk, then I realized that the only game occuring to avoid being at the bottom or to have a product that just doesnt work at all new from the store.
A few years ago my new Kitchen Aid ( Whirlpool ) refrigerator was DOA. The new replacement was a POS until it got fixed with Frigidaire parts under warranty.
 
One day we need to see a room by room tour of this mansion. Housing prices have gone insane. 800k here, 4 bedroom with a garage that can only fit one car on 4 acres with a cheap waterfall in the front yard, overlooking a junk yard. Interior is filled with cheap flooring, fake brick, big open cold spaces with no character, and large windows haphazardly placed for the 'wow' factor of a perspective buyer. There's no wood detail, no real materials used that matter. And worse, the siding is all plastic not wood or brick. Sigh.
Not a mansion by modern standards, now that they're throwing up 6k sq.ft. McMansions all over the place on lots less than an acre. But it is big for an old house, and the age and nature of add-ons translates to the total hodge-podge of heating and cooling systems.

The six refrigerators was my doing, though. A typical American-style big'un in the kitchen, with three under-counter units in the garage, a fifth in the 3rd floor kitchenette (former attic space), and a sixth in the "butler's kitchen" that has now become a combination pantry / coffee bar. We don't have a butler, nor did the prior owners, as far as I know!

Point is... I've become more familiar with refrigerator compressor failure than the average Joe.
 
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So going back to the original post about dryer outside air kits for a sec... I don't know about your dryer but mine has a thermostat that runs the exhaust up to a certain temperature. If you feed it outside air, I think it'd run the elements longer consuming more energy to achieve the same exhaust temperature. So the tradeoff is do I preheat the air using my wood stove or do I heat it 100% with electric before dumping it outside.
Still think I'd prefer to keep all that heat inside if possible, during winter.
 
Between refrigerators, home AC, minisplits, dehumidifiers, and a pool heater, I guess I have 13 heat pumps running in this house (that I can remember). The trouble is, all of those which are installed in portable appliances have horrendously bad reliability. I average 2 - 3 years per dehumidifier, and about the same on refrigerators. Do you really want to be replacing clothes dryers with similar frequency?

Heat pumps can be reliable, one of my largest AC units is near 40 years old, but the cheap ones included in appliances seem to have horrendously bad reliability. Being disposable rather than repairable, this translates to short appliance lifetimes, as noted in my recent "EPA shortsighted" thread about the death of another one of my 2-year old refrigerators.

Can't your mini splits supplant your A/C and dehumidifiers?
 
Can't your mini splits supplant your A/C and dehumidifiers?
Maybe it could work in a smaller home, which doesn't have a basement, and where people didn't care about looking at all those ugly head units. In general, minisplits are too small, too ugly, and all require individual drains, so not really a good choice for whole-house cooling in a larger home. Also, dehumidifiers generally reside in basements around here, and not many people are pumping AC into their basement, if only for eastern-PA's generally-high radon levels, alone.

In my case, I'm only using two minisplit systems to cool two very small spaces (1400 sf + 260 sf) that are isolated from the rest of the house. The main part of the house is cooled by two very large traditionally-ducted Carrier AC units, something like 10 tons total. I presently have two dehumidifiers plumbed up with auto drains in the basement, and since my boiler runs all summer (hot water) that keeps the third "wing" of the basement dry.

edit: I guess the radon comment probably didn't make much sense, and could be something to favor mini-splits. Around here, people generally don't pump traditional ducted AC to their basement, even when they have a finished basement, because basement radon levels in our part of the state are often at or above the treatment threshold (4.0 ppm). But a minisplit exchanges no air with the rest of the living space, making them ideal for cooling a finished basement, if you can deal with the drainage so close to grade.
 
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Maybe it could work in a smaller home, which doesn't have a basement, and where people didn't care about looking at all those ugly head units. In general, minisplits are too small, too ugly, and all require individual drains, so not really a good choice for whole-house cooling in a larger home. Also, dehumidifiers generally reside in basements around here, and not many people are pumping AC into their basement, if only for eastern-PA's generally-high radon levels, alone.

In my case, I'm only using two minisplit systems to cool two very small spaces (1400 sf + 260 sf) that are isolated from the rest of the house. The main part of the house is cooled by two very large traditionally-ducted Carrier AC units, something like 10 tons total. I presently have two dehumidifiers plumbed up with auto drains in the basement, and since my boiler runs all summer (hot water) that keeps the third "wing" of the basement dry.

edit: I guess the radon comment probably didn't make much sense, and could be something to favor mini-splits. Around here, people generally don't pump traditional ducted AC to their basement, even when they have a finished basement, because basement radon levels in our part of the state are often at or above the treatment threshold (4.0 ppm). But a minisplit exchanges no air with the rest of the living space, making them ideal for cooling a finished basement, if you can deal with the drainage so close to grade.
I have a minisplit in my basement along with a heat pump hot water heater. The hot water heater helps remove some moisture/heat during summer, but it isn't enough. The ground temp builds and by late summer it gets stuffy down there without extra AC. In winter i can hang clothes on racks and they dry easily overnight, but the air around here is like the desert in winter. The newer washing machines remove so much water from clothes that they don't take much to dry.

Now that the ground has cooled (the floor isn't insulated/just the walls) the minisplit is basically feeding heat to the hot water heater (i have left it in heat pump mode so far). I may have to flip it to pure electric if it gets too cold outside.
 
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I have a minisplit in my basement along with a heat pump hot water heater.
That sounds ideal. I've had a HPWH on my future projects list for years, but other priorities are forever knocking it lower on the list. My basement stays dry enough, but it does get a bit warm by August, what with a boiler running down there to make hot water all summer. The boiler room is crazy-warm in winter, honestly too warm to do much of anything in there, so a HPWH could be an ideal all-seasons solution here. It would also likely decrease my dehumidification electric costs, if not even dehumidifier count.
 
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The boiler room is crazy-warm in winter, honestly too warm to do much of anything in there,
Is there any way to scavenge that heat to another area via a local ducted ventilation system?
 
Ashful, you are the ideal candidate for a HPWH. If you replaced your boiler hot water with the HPWH, you'd probably save $50-100 per month, depending on how much hot water you use.
 
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Is there any way to scavenge that heat to another area via a local ducted ventilation system?
We do a little bit of that, but not a great job with it. Some of the heat is used to keep the adjacent basement rec room near 60F without running that zone, which also helps keep the floors in the main part of the house from being quite as cold. Even more of it warms the kitchen floor, as that's right above the boiler room. But most of it probably goes into the unfinished stone walls of the boiler room, so as DBoon already indicated, I think the best path for us is a HPWH.

I looked into them years ago, with the idea of getting an indirect one to tag onto my existing boilermate tank, but didn't find anything really suitable. Since then I've resigned to just adding a duplicate tank, essentially a regular Rheem style HPWH with tank upstream of the boilermate. The HPWH can do all the heavy lifting, bringing water from 50F up to whatever it can do without resistive backup, then the boilermate can top it up to final temperature and store. The boiler will still run for hot water, but probably a small fraction of the amount it runs today, for that purpose.
 
I looked into them years ago, with the idea of getting an indirect one to tag onto my existing boilermate tank, but didn't find anything really suitable. Since then I've resigned to just adding a duplicate tank, essentially a regular Rheem style HPWH with tank upstream of the boilermate. The HPWH can do all the heavy lifting, bringing water from 50F up to whatever it can do without resistive backup, then the boilermate can top it up to final temperature and store. The boiler will still run for hot water, but probably a small fraction of the amount it runs today, for that purpose.

You could do that, but I wouldn't be excited about it either due to complexity. Are you heating the water very high, and then tempering it back down? Or are you cruising the boilermate at 125°F? If the latter, the HPWH can reach that with a EF approaching 3.0, and the boiler would not call.

The NICE thing about this is that you get 2X the storage, and the boilermate could step in when the HPWH is exhausted. With a bigger family, you would exhaust even a 80 gal tank I'd bet, and no one would want to wait 4 hours for a recovery. And on that basis, you could get a smaller HPWH, which are a lot cheaper and quieter.

High EF and endless hot water and 'free' dehumidification.

Looks like the Feds will give you $600 and PA will give you $350.
 
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I think the boiler must have enough horsepower and exchange efficiency to already give me endless hot water, as we've never run out. I have one teenager who takes endlessly long showers, almost competing with my wife on that, and all four of us can shower back to back using two bathrooms and we never run out.

I'm with you on disliking the complexity, and even more on the sheer space it will take up. I also have a very low ceiling in the boiler room, which will require me to move some existing plumbing around just to fit a tank HPWH, and then top-accessible filter cleaning might be a real problem. That has been the primary obstacle.

But there are a few legit reasons to keep the boiler downstream of the HPWH, rather than just ditching it and running solely on HPWH:

1. Either way, the HPWH would have a relatively small reservoir and long recovery time, so I could see us often running out of hot water if that were our sole source.

2. The boiler runs just fine in a power outage, the whole rig probably only pulls a few amps from our portable generator backfeed. I don't presently have generator capacity to run house + well pump + HPWH.

3. Yes, we have that boiler mate set screaming hot. There's no thermostat marked in degrees, just something like 1 - 5 with a "scalding" warning line that we are way beyond. I'd bet we're just a few degrees off making steam in the damn thing, but that works well when some of the appliances are at long distance from the water heater, or when you are blasting food off a plate the kids left dry on the counter. My wife also tends to take scalding showers, so damn hot I feel like I'm going to burn my arm if I reach in for a pinch. ;lol

begreen, if we're reaching our "off topic post count threshold", feel free to split this off into a new thread. Just post a link back here so we can find it. Thanks!
 
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Either way, the HPWH would have a relatively small reservoir and long recovery time, so I could see us often running out of hot water if that were our sole source.
Just a data point to add - I just returned from 10 days away and had the HPWH in "Vacation" mode (only keeps the water at 60 degrees F). I flushed it out on my return (water out of the tap was 64 degrees) and it filled with 80 degree water (cold inlet for HPWH passes through a heat exchanger on my geothermal water storage tank). Faucet outlet temp said 75 degrees when I stopped draining the tank (a side note - I drain the tank because I get a hydrogen sulfide smell after an extended stay away because sulfur bacteria grow on my water heater anode rod). It took 3 hours for the HPWH to get the tank temperature from 75 to 115 degrees F - not awesome, but also not crazy long either.