Should my neighbor run their AC refrigerant lines through my garage?

Question

I live in a 2-unit town home. I have installed an AC on the side of my unit. My neighbor would like to install an AC for their unit. However the city codes will not allow them to install it on the side of their house since it is too close to the property boundary. The front and back of their unit is also prohibited by other codes.

One solution is to allow them to install their AC on my side of the house (shared property) and run the refrigerant lines thru my garage. Are there any problems I should be aware of for this kind of arrangement? Are there any alternatives that folks can think of that doesn't involve going thru my garage?

Answer 1

No, you should not run refrigerant lines through your property. There are many reasons:

• They will require access to the unit to repair lines.
• A split system, like you are suggesting, has two lines, one of which is often cold. This causes condensation on the line, and if the insulation isn't 100% it's your property the line will be sweating into.
• You can only damage the lines, there is perpetual risk to you, with no benefit.
• The lines being damaged, can only harm you; again there is no benefit.
• The agreement you and your neighbor make will have difficulty surviving new neighbors, as well as complicate the sale of your property.

There is an alternative. Have you neighbor look into a roof top mounted AC stand.

• This keeps the property lines where they are, without encroachments.
• The stands themselves are rather cheap (under $200)
• Access to the AC is a bit more complicated, but not "enter my neighbor's house with a stranger technician complicated."
• A crane will have to lift the unit in place, which typically adds $100 to $200.

However, if anything goes wrong, it's not going wrong in your home. Having something go wrong in your home, even if you had nothing to do with the failure, will put stress and pressure on the neighbor and your relationship. Even if you are completely helpful to the neighbor, there will be ways that you could have been more helpful; and, if you neighbor is pushing for access, even once, you might find yourself in the position of not wanting to help them.

Answer 2

Problems that come to mind:

1. Liability if you damage the lines.
2. Liability if the lines damage your property.
3. Access to the lines in the event of repair or replacement.
4. What if the property is sold and the new owner is a some sort of a jerk?

I'm sure any or all of the above are manageable but this is something that you may want to discuss with an attorney and have the appropriate documents drawn up.

Answer 3

Everyone is correct, you should not allow it. In fact, it’s your duty to not allow it.

Look at your deed and it will say something about NOT allowing other improvements to encroach onto the property. This includes buildings considered duplexes , tri-plexes, etc.

Also, I’d check with your title company. They certify that your building is “only on” your property and “no other improvements encroach “.

Answer 4

Don't run the lines across or through your property. Your neighbour should consider something more compact like a side-discharge A/C unit. These are available for both mini-split and central A/C units and would certainly fit on your neighbour's side.

Side-discharge units can even be mounted directly to the side of the building and won't even extend past the eaves, so there should be no issue with it being too close to the property line. This is also much less of an eyesore than anything roof mounted.

If your neighbour is dead set on a top-discharge unit, you could still try applying to the city for a variance to allow them to install it anyway. Often the rules about how close to the property line you can build can be waived in special circumstances. Those rules are there to keep generally sane margins around a property, but there are many special circumstances where building up to the line is necessary and most cities are reasonably understanding in those cases. Here it's clearly a better idea for your neighbour to put their A/C on their side rather than some sort of nightmare of wiring and refrigerant lines crossing through your property.

Answer 5

Are there any alternatives that folks can think of that doesn't involve going thru my garage?

• On the front or in the front yard (unusual)
• On the back (usual)
• In the backyard (usual)
• On the roof (fairly usual, especially if yard space is limited or subject to damage/vandalism - though unusual in much of suburbia)
• Inside the attic (if there's an attic)(standard some places, unusual in others.) There are vents to the outdoors, of course

Answer 6

If by ducts you mean the air supply and return ducts, then no, you should not allow that. That creates an unnecessary fire risk between your homes.

Instead, your neighbor should install a split system so that only the refrigerant lines and wiring pass through your house. They could even be run around the outside of your house.

Answer 7

Not an answer, but this is the only way I could post a picture of a friend's house in the city, with the AC unit sitting on the sidewalk next to the house right behind the mail box. Yes, he had to go to the city to get a waiver to do that.

OP - Has your neighbor applied for a variance? That should be the first approach. Like others have said, almost all jurisdictions have a process whereby bulk requirements (like building setbacks) can be waived.

Answer 8

For 'Are there any alternatives': if you're not in a location where you need active cooling 24/7/365, your neighbour could consider ditching the chiller component of the AC, and instead using phase change materials for temperature regulation. (On a careful analysis, they might even find that the moisture content of outdoor air in your area is low enough that the dehumidifier component of the AC is also unnecessary, and/or that they can get all the fresh air they need using displacement-mode natural ventilation, rendering the fan component unnecessary.)

Answer 9

Yes, just use suitable conduit for some extra peace of mind.

I can't comment on the legal/contract details of how to set this up in the US, but technically there should be no issue doing it the way it's done in my house in the EU. Just install a pair of straight 40mm(-ish) steel pipes as a sort of conduit and then run the AC lines inside those.

• No risk of you damaging the AC lines as it's pretty much impossible to accidentally drill through several millimeters of steel
• No risk of the lines damaging your property (again, any leak will be contained and carried away by the conduit), same for anything nasty possibly infiltrating from your neighbour's property (fire, bugs)
• If the AC lines have to be replaced later, it can be done without opening walls or entering your house at all (just uncap the conduit, pull out old line, pull new one in). (But I suspect this isn't going to be necessary at all, chances of a leak developing in the middle of a straight copper pipe are likely negligible.)
• If you can manage to run this through a wall that won't ever be moved (load-bearing/external) or in the ceiling, it's not going to limit you in the future.