# HVAC Guys, Garage Heating
**URL:** https://forums.speedlife.net/t/hvac-guys-garage-heating/160832
**Category:** NYSpeed Off Topic
**Created:** [September 27, 2010, 2:01pm UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832 "2010-09-27T14:01:49Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@n20junkie](https://forums.speedlife.net/u/n20junkie)
#### Post date: [September 27, 2010, 2:01pm UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/1 "2010-09-27T14:01:49Z")
I am looking to add a circuit to my home boiler to heat an attached 20x20 garage. Its a block building with a brand new insulated ceiling and insulated doors.
The house is a small 1,100 sq foot house, fully insulated. The boiler is a 84,000 BTU Dunkirk unit. I believe there is ALOT of extra output in the boiler becuase the think almost never cycles the burner. I don’t want a tropical warm garage, 50 degrees is more than enough.
I looked into adding a Modine Hot Dawg heater, but think adding an additional circuit to the boiler would be much easier, and would be a simple system. Do any of the HVAC guys here have any experiance with garage hydronic heaters? I also need a local supplier for the unit, around 50k BTU with an fan. Thanks for the help.
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### Author:  [@66impalass](https://forums.speedlife.net/u/66impalass)
#### Post date: [September 27, 2010, 3:23pm UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/2 "2010-09-27T15:23:11Z")
Whats the flow of the boiler and the pump? That will be your limiting factor here. also is the garage attached to the home? If not you need to do a lot of insulation and such to keep the piping with a minimum of 250°. I honestly think the unit is too small as that is a smaller unit than I put in similarly sized projects, I personally use a minimum of a 199mbh unit everywhere.
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### Author:  [@n20junkie](https://forums.speedlife.net/u/n20junkie)
#### Post date: [September 27, 2010, 7:41pm UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/3 "2010-09-27T19:41:16Z")
It’s an attached garage. The garage exchanger would be 25 tubing feet from the boiler. The pump is a 20gpm 1/25th horse 007-F5 model. The boiler is a Dunkirk PWX-4VNT2 I can’t seem to find flow numbers and it’s notna current model.
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### Author:  [@Harvey](https://forums.speedlife.net/u/Harvey)
#### Post date: [September 28, 2010, 4:47am UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/4 "2010-09-28T04:47:23Z")
84k btu/h for a 1100 sq-ft house is overkill, unless you leave your windows open and have no insulation. I would run the new zone with it’s own pump instead of adding a zone valve.
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### Author:  [@LUKE\_L](https://forums.speedlife.net/u/LUKE_L)
#### Post date: [September 28, 2010, 5:00am UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/5 "2010-09-28T05:00:12Z")
Would adding another pump starve the boilers heat exchanger at all? I have 1600 sq-ft house with 3 Zone and a non-heated, attached, 900 sq-ft garage. I want to add the garage as a seperate line as you mentioned. Is there anything with regards to the boiler I should be concerned about? I literally thought of this for about 30 seconds after you suggested adding a second pump, ILI.
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### Author:  [@Harvey](https://forums.speedlife.net/u/Harvey)
#### Post date: [September 28, 2010, 6:08am UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/6 "2010-09-28T06:08:45Z")
The pumps go in parallel, so if both zones are on there will be more flow. Since your whole system is 12-15 psi, starvation is not a concern. Low flow through a boiler is much worse than too much flow.
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### Author:  [@LUKE\_L](https://forums.speedlife.net/u/LUKE_L)
#### Post date: [September 28, 2010, 6:17am UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/7 "2010-09-28T06:17:35Z")
Makes sense. Thanks.
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### Author:  [@n20junkie](https://forums.speedlife.net/u/n20junkie)
#### Post date: [September 28, 2010, 9:48am UTC](https://forums.speedlife.net/t/hvac-guys-garage-heating/160832/8 "2010-09-28T09:48:57Z")
Ok so I’m not crazy for thinking i have lots of extra boiler capacity. Where it’s the best local place to get a heat exchanger and other circuit components like a pump and stuff?