Desuperheater - Anyone installed one?

Hey_Obie

One of the biggest wastes of energy that gets little attention is

Since I have been on my quest to replace my 30 year old boiler with a new more efficient model, I have been thinking about energy wastes in the house.

One of the most stupid ones is the electric dryer in the winter.  We are using expensive electric heat to dry clothes and then send the hot air in a duct into the cold outside air.  That one I fixed with a little plastic box you can buy on ebay for $10-20 bucks

<a href="http://cgi.ebay.com/DRYER-VENT-HEAT-KEEPER-PERFECT-FOR-DRY-WINTER-MONTHS_W0QQitemZ120526125610QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item1c0feaba2a">http://cgi.ebay.com/DRYER-VENT-HEAT-KEEPER-PERFECT-FOR-DRY-WINTER-MONTHS_W0QQitemZ120526125610QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item1c0feaba2a</a>

But the one that really is bad is airconditioning your house with a heat pump (throwing hot air outside) and at the same time heating hot water with electricity.  Opposites.

There are a couple good solutions to this waste.  One is the hot water heater with a heatump attached to it.  Very expensive at $1500. 

The best is a desuperheater. Through a freon to water heat exchanger, you can gather discarded heat from the air conditioner and use it to heat your hot water.  Basically for the cost of running a circulator pump

For about $600 in equipement (I am told it qualifies for the tax credit so that gets you to about $400).  The installation is expensive unless you can do it yourself.

Anyone ever installed a desuperheater?

Wayne_16

There are used all the time in the commercial industry

Even the large dairy's use desuperheaters from the bulk tank to warm the incoming water prior to the water heater.



I agree, lets take the low hanging fruit, and a desuperheater does that.

Econar and other heat pump manufacturers have used the desuperheater option for many years with great results. 

I have thought about installing one on my own air conditioning system.  The added work and hassle has prevented any installation.   The most practical location for a desuperheater on a air conditioner is inside the the building envelope.  This would prevent freezing the coil.



From a manufacturing standpoint for air source heat pumps or air conditioners, would raise the installation cost, refrigerant piping concerns, oil return, condensing in the wrong location etc. are issues the manufacturers would have to design and eliminate possible problems prior to introducing them to the market.  Lets be honest, most installers will not take the time or expense to do the job properly.  It is all about in out-quick.



Minnesota Wayne

HDE_2

1 good, 1 bad

You will quickly remove that dryer box when you discover how dirty the inside of your home is getting, besides the excess humidity added, you may not want.

I have a desuperheater on my main floor AC unit, I use the heat to preheat a 50g electric storage tank, it works real well and living in the south, my tankless water heater never fires as long as DHW use is spread out, for about 8 months of the year. In fact in the summer I have more than I need and considered sending it to the pool, but thats only about 2 months, and the titanium ht ex and components wouldn't be worth the investment with the ROI.

Note: I installed it myself, having access to reclaimer, vac pump, brazing torch, guages, & extra gas needed)

Hey_Obie

How long did it take you?

I am smart enough to know that I don't have the skills/experience to install it myself. I can run the piping but don't have brazing equipment nor HVAC skills to extract the coolant, braze the pipes. vacuum it out and load it back up.



I am going to check into getting prices to get it done.



By the way, I have a very different box that I connect to my dryer. I just grabbed something off of ebay as an example and it was wrong. My box contains water. The air blows on to the top of the water and traps most of the lint. We have to change the water which gets gross. We like the humidity which isn't bad. We pick up some lint but nothing we talk about. Works pretty good for $20. Just kills me to chuck the heat out the vent.



The refrigerator in the summer is another one that bothers me. We are throwing hot air into the kitchen and then air conditioning the house. Small potatoes, but conflicting systems

Unknown

"air blows on to the top of the water and traps most of the lint"

I`ve seen those,, they sit on the floor(or stable shelf), also saw those "box" deals too,, although both may be a good "heat reclaimer", one would wonder what it may do to a persons respiratory system in the long run?

Anyone remember asbestos or lead paint?



We all need a plastic bubble with a toilet in-it to survive,, but then again who`s going to pay our taxes?

Constantin

I'm still considering them...

... but given our relatively short cooling season, a desuperator isn't going to ave the same benefit up here as in the south, especially with a large condenser HX. Heating the in-home water will most likely be the only result (which is nice) but some of the SEER/EER performance gains that you can see on older systems retrofitted with a desuperator are hence unlikely.



Instead of a external unit (like the aquifier, etc.) I'd opt for a simple refrigerant/glycol HX, put both condensers in series and run the loop with a dedicated pump if either condenser calls for heat. The glycol loop would be teed' off the solar system loop... easy enough. But with some of the other changes I am making around here, I want to see if the added DHW heating bonus of the condenser desuperators actually makes sense.

Rollie

Desuperheater

      One of the problems associated with recycling electric dryer exhaust close to the dryer is that the moist air gets drawn in to the dryer intake, causing the dryer to run much longer to get the clothes dry.



       I have good results exhausting the dryer down through the floor and into a boxed off section of ceiling joists in the partially unfinished downstairs bathroom. The section  is covered with three 15 x 25 inch furnace type air filters. The warm, moist air helps heat the bathroom and by the time it traverses half of the lower level, the stairway through the front entry and back to the dryer on the upper level,  it has mixed well with other air in the house.  When the heat is no longer desired in the house, I switch the pipe to an external vent on the side of the house.



        I would not do this with a gas dryer because of the gas fumes.  Fumes from the anti-static sheets could be a problem, but we haven't noticed anything yet.



Rollie



Homneowner