Hot water Loop Heat Loss

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Hello everybody!

I am trying to define heat loss that occurs on the hot water loop.

Unit of "Supply Loss DT" is just F? and unit of "Supply Loss UA" is Btu/h.F?.

Although, a small value input is given, the consumption increases extremely.

Actually, I can't get how it works. And, I think there could be some mistakes on units that the units are per ft actually, maybe.

Is there anyone who experienced the same thing?

Thanks in advance!

via Equest-users's picture
Joined: 2016-07-15
Reputation: 400

Hello,

Supply losses from the loop are modelled by setting the "Supply Loss UA? value in Btu/hr-?F. When this value is set eQUEST asks you to enter a zone location. Supply losses are then calculated by taking the difference in temperature between the zone and the water loop at every hour and multiplying this by ?Supply Loss UA?. The supply loss UA should be calculated beforehand from what you know about the pipe insulation (i.e. conductivity) and the diameter of the pipe. According to the DOE-2 Dictionary "Supply Loss DT? is an alternative entry (i.e. another way of specifying heat losses through the pipe) to ?Supply Loss UA? and is ignored if a value has been entered for ?Supply Loss UA?.

Hope that helps,

Dan

?
Daniel Knapp, PhD, PPhys, BEMP, LEED AP
Senior Energy Analyst
ARBORUS CONSULTING
43 Eccles St. 2nd Floor,
Ottawa, ON K1R 6S3
(613) 234-7178 x113
danielk at arborus.ca
http://www.arborus.ca Check out our new website!

Form follows Nature?Building a Net Positive Environment
Join us October 5, 2017 at the Annual Green Building Festival,
Visit the conference website: www.gbf17.com

via Equest-users's picture
Joined: 2016-07-15
Reputation: 400

Just a quick follow up. The length of the pipe will also factor into the UA calculation.

?
Daniel Knapp, PhD, PPhys, BEMP, LEED AP
Senior Energy Analyst
ARBORUS CONSULTING
43 Eccles St. 2nd Floor,
Ottawa, ON K1R 6S3
(613) 234-7178 x113
danielk at arborus.ca
http://www.arborus.ca Check out our new website!

Form follows Nature?Building a Net Positive Environment
Join us October 5, 2017 at the Annual Green Building Festival,
Visit the conference website: www.gbf17.com

via Equest-users's picture
Joined: 2016-07-15
Reputation: 400