I have kinda an odd one. I'm mostly concerned about fire safety here and am not concerned about power, I already know how to handle that properly.

I have a somewhat large basement with an unfinished storage room that is probably 150 square feet total. The room also contains the gas water heater and furnace. I have a 19" server rack that I'd like to put in there and run 2 or 3 servers in it at a time. These are servers that draw 300W of power and so generate about 3000 BTUs of heat per hour. There are not any combustibles next to the water heater, furnace or servers.

My questions are:

  • Is it safe to run servers/computers next to a gas water heater if I give them about 3-4 feet of clearance?

  • Will I have to worry about the heat generated by the servers not being handled by the airflow?


3x 300 watt servers together would produce ~3070 BTU/hr. ~1023 BTU/hr each.

There's no particular hazard to running the servers near a water heater or furnace, other than the heat associated with those items raising the baseline before you add the heat thrown off by the servers. Most system administrators would choose not to but that's from a "hazard to the computer" point of view, not fire hazard - Nothing quite like having a water heater fail and spray your servers with hot water to ruin whatever service you were running on them.

You have provided no data on airflow or ventilation - it's certainly possible that the temperature may become excessive without some active ventilation and/or cooling.

If the ceiling height is 8 feet, there's about 89 lbs of air in the room. The specific heat of air is 0.24 BTU/lb/degreeF (varies somewhat with temperature and pressure), so in the absence of airflow into or out of the room and with infinitely insulating walls/floor/ceiling, you'd be looking at ~140F temperature rise per hour. Might be a bit toasty for the servers, though it would save a bit on hot water bills. Real walls, floor, ceiling will bleed off some heat, but you still might have a problem without some active ventilation. During the heating season you may well be able to arrange the cold air return so that the servers get cooler air and contribute to heating the house - in warmer weather you'll want to dump heat somewhere else, though you could get some benefit by using a heat pump water heater (or just an add-on unit) to provide some (erratic, as you use hot water) cooling and make use of the heat from the servers.

  • +1 for "hazard to the computer". I'd also consider that in most basements, the computers are going to be collecting a lot more dust which will also make them run hotter and increase wear on the fans. – Comintern Apr 6 '14 at 17:48

I think that no matter where you put those servers, whether in a storage room or near to your actual computers, you should really do something about the heat generated. There are proper cooling systems that you should have in place to make sure that your electronic bits are kept cool and don't overheat.


I have a lab at work right next to water heaters and air conditioning unit. I got the space for free and the "good" space is production stuff. I have not even thought about the units until your question, and will soon forget about them. They mean nothing.

Pretty much there are three things to worry about. Temperature, humidity, and drastic changes in temperature. Room should optimally stay below 75 degrees Fahrenheit. You could probably run 10 servers in an open rack and be fine in a basement room that size... maybe 20-30. Air flow really doesn't matter. However my only issue with your basement is the humidity levels in that room. Higher humidity will eventually cause some components on your motherboard to fail/rust/deteriorate. This won't be any consequence to you until your servers are in there for a while. It might give them a shelf life of 3-4 years instead of 6-7. It isn't a huge deal but these kinds of problems are just a PITA to troubleshoot.

The temperature swings are a bigger deal because they can leave condensation everywhere, including in HDDs. This is a much bigger deal and I don't think it is an issue unless you treat your house as an unconditioned space... Just don't leave heat/air off when leaving on vacation for a few weeks.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.