Tankless water heater vent near AC condenser

[dstryker]

I am thinking about purchasing a tankless water heater, possibly the Rinnai Rl94i or the Rl75i.

According to what I have read and the clearances listed in this PDF by Rinnai these are the clearances that would apply to my install.

• 36" from an opening window.

• 36" above grade.

• 12" from an inside corner.

Do these all sound correct so far? Because I am limited as to where I can place the water heater inside and considering all the clearances above, that leaves only one place that is practical for the vent to exit the house and that is about 30" from my AC condenser unit. If you look at the attached picture you can see the location is exactly where the current power shutoff for the AC condenser unit is, which I will have to move. My question is, will this be too close to the condenser? Will the condenser disturb the airflow for the vent and intake of the water heater?

Also, any opinions of those two water heater models?

Thanks

 

[johnjh2o]

Can't say for sure but my first impression is there would be to much air movement produced by the condenser.

John

 

[plumbingjim17]

Where I live the configuration you going for would not meet code also they have restrictions on if you have an eave above for the roof line too but you could come out by the electrical box as planned and put a 45 degree on it so its pushing the air in a direction away from the condenser or rise up a little away from it then 45 or so if that meets code where you live but where I live the window above looks to close for it to meet code especially if there is an eave above there But without measuring and looking at all options it don't look like this is a great idea to me there is to many things that could go wrong in this location.

 

[LiQuId]

Rinnai is the very most hated on demand water heater i have ever had the displeasure of working on.... they are pure crap IMO.

dont do it... my 2c

 

[JayP]

since the code guys have already pointed out clearances, i will chime in on it from an electrical engineer prospective.

there is already too many things venting there. AC unit is not going to work very efficiently if water heater is venting hot air on it. I went to a customer house a complaint about burning up AC equipment every few years. Electrician told customer it was a low voltage problem - it wasn't. AC unit was rated down to 208 volts, voltage was around 215 and not flunctuating.

When I got there I found three 2 ton units surrounded by closely spaced picket fence with water heater and furnaced vented right next to AC units.

the units couldn't breathe and transfer the heat to atmosphere fast enough, causing the AC units to work their asses off and reduce working life.

always remember changing seasons and ambient delta T's are going to vary. Set up for worst case. When it's 100 degrees out and your doing ten loads of laundry and drying it, that needs to be considered.

 

[havasu]

Thanks for your comment Jay. And welcome to the forum!