Heating issues plumbed under the house

[jdolores]

Here's the layout

Display tank 120 gallon plumbed to the garage. From the display to the sump were talking about 15-18 feet of travel. Sump is 55 gallon but only 1/3 is filled. Connected to the sump is a 75 gallon refugium. External pump used is a RXLT40 iwaki. For heating I have four 250 watt stealths in the sump.

Total amount of water volume calculated is 220 gallons.

There is a 1 degree diffrence from the sump temp to the display tank. Sump 78 display would be 77.

This morning it was a little more chillier than normal and I saw display at 76 and sump at 77. All heaters were on seen through my RK2.

***My question is, should I move two larger heaters like two 800 watts, Does anyone recommend anything else. I just know to have multiple heaters just in case one goes out.*** Thanks

 

[tgunn]

Re: Heating issues plumbed under the house

<a href=showthread.php?s=&postid=13384642#post13384642 target=_blank>Originally posted</a> by jdolores
Here's the layout

Display tank 120 gallon plumbed to the garage. From the display to the sump were talking about 15-18 feet of travel. Sump is 55 gallon but only 1/3 is filled. Connected to the sump is a 75 gallon refugium. External pump used is a RXLT40 iwaki. For heating I have four 250 watt stealths in the sump.

Total amount of water volume calculated is 220 gallons.

There is a 1 degree diffrence from the sump temp to the display tank. Sump 78 display would be 77.

This morning it was a little more chillier than normal and I saw display at 76 and sump at 77. All heaters were on seen through my RK2.

***My question is, should I move two larger heaters like two 800 watts, Does anyone recommend anything else. I just know to have multiple heaters just in case one goes out.*** Thanks

Do you have any indication of how long the heaters were running? I'd be surprised if they were running continously. That's a lot of heat for a 120! I've got two 250w heaters in my 140, and they don't run very often with the exception of winter when the energy saving thermostat drops the temperature to 63F during the night.

You can always try insulating the pipe runs, but i bet a majority of your heat loss is from the tanks.

Tyler

 

[jdolores]

Re: Re: Heating issues plumbed under the house

Re: Re: Heating issues plumbed under the house

<a href=showthread.php?s=&postid=13384728#post13384728 target=_blank>Originally posted</a> by tgunn
Do you have any indication of how long the heaters were running? I'd be surprised if they were running continously. That's a lot of heat for a 120! I've got two 250w heaters in my 140, and they don't run very often with the exception of winter when the energy saving thermostat drops the temperature to 63F during the night.

You can always try insulating the pipe runs, but i bet a majority of your heat loss is from the tanks.

Tyler

I never thought of this but the pipe coming from the overflow to the sump is 2 inch diameter. Lets say coming from the over flow and going under the house and back up to the sump were talking about 20 feet of water being exposed to cold temps. Thats no counting the 1 inch piping going back to the display tank too. So I'm thinking with all that water in transition in the pipes were talking about 20 to 30 gallons being exposed to a colder climate. Hence the 1 degree drop between the sump and the main tank.

 

[tgunn]

Re: Re: Re: Heating issues plumbed under the house

Re: Re: Re: Heating issues plumbed under the house

<a href=showthread.php?s=&postid=13384842#post13384842 target=_blank>Originally posted</a> by jdolores
I never thought of this but the pipe coming from the overflow to the sump is 2 inch diameter. Lets say coming from the over flow and going under the house and back up to the sump were talking about 20 feet of water being exposed to cold temps. Thats no counting the 1 inch piping going back to the display tank too. So I'm thinking with all that water in transition in the pipes were talking about 20 to 30 gallons being exposed to a colder climate. Hence the 1 degree drop between the sump and the main tank.

How much flow through the sump are you getting roughly? And how cold do you consider cold?

A simple test would be to test the temperature of the water in the overflow, and the temperature of the water coming out of the drain line in the sump. If you're getting a measurable temperature drop then I'd insulate those pipes up.

How much do you evaporate? Evaporation can make a HUGE difference. If I turn the fan on over the sump it dissipates enough heat through evaporation that both my 250w heaters turn on, where otherwise they'd be off.

Tyler

 

[jdolores]

Re: Re: Re: Re: Heating issues plumbed under the house

Re: Re: Re: Re: Heating issues plumbed under the house

<a href=showthread.php?s=&postid=13384917#post13384917 target=_blank>Originally posted</a> by tgunn
How much flow through the sump are you getting roughly? And how cold do you consider cold?

A simple test would be to test the temperature of the water in the overflow, and the temperature of the water coming out of the drain line in the sump. If you're getting a measurable temperature drop then I'd insulate those pipes up.

How much do you evaporate? Evaporation can make a HUGE difference. If I turn the fan on over the sump it dissipates enough heat through evaporation that both my 250w heaters turn on, where otherwise they'd be off.

Tyler

Evaporation is about 1 to 1.5 gallons a day not much when its cold. Cold to me is having my display tank at a 75.8 which was the lowest. Is that bad? If its not what the lowest for a reef tank? I know with SPS a 1 degree drop can create some problems, if I remember correctly?

I'll test the temps and come back with some #'s. Thanks

 

[tgunn]

Re: Re: Re: Re: Re: Heating issues plumbed under the house

Re: Re: Re: Re: Re: Heating issues plumbed under the house

<a href=showthread.php?s=&postid=13385373#post13385373 target=_blank>Originally posted</a> by jdolores
Evaporation is about 1 to 1.5 gallons a day not much when its cold. Cold to me is having my display tank at a 75.8 which was the lowest. Is that bad? If its not what the lowest for a reef tank? I know with SPS a 1 degree drop can create some problems, if I remember correctly?

I'll test the temps and come back with some #'s. Thanks

I guess I'm curious what temperature the rooms the sump and tank are at when your tank gets down to 75.8. Also the outdoor temperature.

I try to keep my tank at 78F minimum. I think 75.8 is probably on the low side.

I think as long as the temperature swings slowly you should be okay. On really warm days my tank can get up to 82F, and drop down to 78-79F at night. I haven't experienced any problems as a result. These temperature swings happen slowly though. The tank will heat up over a number of hours, and cool down over a number of hours.

IT also really depends on the equipment you've got. I used to run 2 PCX-70 pumps and a huge Sequence 1000 closed loop pump on my system. With all those pumps I had a hard time keeping the temperature at 82F even with fans over the sump. I've now got the single Sequence 1000 return pump, Tunzes for my main circulation, and my skimmer is an efficient needlewheel unit. Really cuts back on the heat in the system.


Tyler

 

[savethereef]

wow my tank runs at 83F with out fans. i have never been able to keep it at 77 with out the use of a chiller.

You temp seems fine though. 77-78 is best you can have your temp from 77-83 as long as its stable and does not fluctuate more that 1-2 degreess

 

[jdolores]

Okay, here's the #'s.

Temp in display tank 77.6
Temp coming into the sump 76.9

Temp outside: 68
Temp in house: 70
Under house: Guess is 65-67?