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best location for water tank connected to desuperheater
Last Post 27 Jul 2014 11:24 AM by
rwgardner
. 4 Replies.
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rwgardner
New Member
Posts:42
09 Jul 2014 01:45 PM
I'm getting a secondary water buffer/storage tank to connect to the desuperheater on my Waterfurnace install.
The Waterfurnace and existing water heater are about 20 feet apart.
Is it more efficient to put the secondary tank next to the water heater, next to the waterfurnace unit, or does it matter? (My main thoughts are that the pipes will probably be among the most significant source of heat loss, even if insulated so which ones are longer may matter. It may be, for example, that the desuperheater is constantly cycling water around to the secondary tank, in which case long pipes between the two might be worse than long pipes between the storage tank and water heater. I'm imagining that transfers between the two tanks will be in fairly large amounts at relatively short bursts.)
Thanks.
Bergy
Basic Member
Posts:277
09 Jul 2014 03:32 PM
Piping between the Geo and Buffer is 1/2", between tanks is 3/4". 1/2"
is cheaper... Keep the tanks together,
joe.ami
Veteran Member
Posts:4377
11 Jul 2014 08:27 AM
The closer the tanks the better, but you get benefit from the DSH and buffer regardless. Insulate the line in between.
j
Joe Hardin
www.amicontracting.com
We Dig Comfort!
www.doityourselfgeothermal.com
Dig Your Own Comfort!
engineer
Veteran Member
Posts:2749
20 Jul 2014 10:26 PM
Well, as usual, I have a slightly different take:
Water is circulated between heat pump and buffer tank up to 12, even 16 hours per day...keep those lines short and very well insulated.
Water moves between buffer and finish tank maybe 1 hour / day, max 2; only during actual hot water draw events (showers, dishwasher, clothes washer fills), so that line is less critical. Certainly worth well insulating, but not as much concern about length.
Heat pump to buffer needs two 1/2" lines. Buffer to finish needs one 3/4" line. Is the cost diff between two @ 1/2" vs 1 @ 3/4" so much?
Curt Kinder <br><br>
The truth is incontrovertible. Malice may attack it, ignorance may deride it, but in the end, there it is - Winston Churchill <br><br><a href="http://www.greenersolutionsair.com">www.greenersolutionsair.com</a>
rwgardner
New Member
Posts:42
27 Jul 2014 11:24 AM
Thank you all for the replies.
Yeah, what you're saying Curt, makes most sense to me (also largely what I was saying my intuition was). The pipe between the waterfurnace and buffer tank can be cooled constantly (as long as the water is circulating) whereas the other will only be cooled for a short period of time, i.e., until it's reached room temp. (until someone uses hot water again and puts new water in the pipe). I feel confident that having short lines between the desuperheater and buffer tank is best now. Unfortunately, the contractors recommend putting and put the buffer tank across the basement next to the water heater (probably because the piping was cheaper). Oh well. I should have stuck to what I knew.
I'm also with Curt on the cost. I'm spending about $35K for a very efficient system (not including tax incentives). The few dollars difference in pipe doesn't make sense to me for something less efficient.
Thanks again.
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