Water Droplets on Window Sill

rosaliedipietro2

It's been very cold here in the NYC area for the past few days (below 25 degrees farenheit) One of my tenants complains that the apartment is not hot enough even the the smart thermostat is registering 72 degrees. It's a two bedroom apartment with baseboard heating powered by a Navien Combi Boiler.

Yesterday, I sent them the Frost Window Insulation Kits to help keep from losing heat though the double hung windows.

They tell me that they have to dry the window as they always get water droplets.

If they are getting water droplets on the window sills, doesn't it mean that the room is too hot and causing condensation.

The smart thermostat has settings that I put in however, the tenant can push the thermostat up to 72 degrees on their own.

Can someone help me figure out if I'm dealing with a crazy tenant or if the droplets mean there's an issue I need to address.

Thanks!

ethicalpaul

Heat doesn't cause condensation. Warm moist air coming into contact with a cold surface does. Of course, warm air can hold more moisture than cold air, that's the issue. Whether there is "too much" moisture in the air is not something we can tell from here but can be exacerbated by poor/no bathroom/kitchen venting, leaking steam radiators, people working out too much, etc etc etc

Insulation on the windows can help this issue, as the window's cold surface will presumably not be exposed to the warm moist air as much.

Larry Weingarten

Hi, To me, this means that indoor air is getting to the cold glass and being cooled, dropping it's humidity as condensation on the glass/sill. It suggests that the window insulation kits are not sealing well and that indoor air is still able to flow in and out from between the glass and insulation. Is there a way to make the insulation seal tighter? Another possibility is that humidity is traveling up or down through the wall and then condensing on the glass. That would be a much harder problem to solve.

No doubt others will have useful thoughts.

Yours, Larry

pecmsg

72 is not hot enough?

Jamie Hall

Either interior storm windows or exterior ones will help -- sometimes even eliminate the problem. As others have suggested, though, the problem can be severe in a smallish apartment. The main culprits are the bathroom with no vent fan -- or a vent fan which isn't used -- and cooking, again with no exterior vent or one which isn't used. Not much you can do about that.

ethicalpaul

Larry Weingarten said:

Hi, To me, this means that indoor air is getting to the cold glass and being cooled, dropping it's humidity as condensation on the glass/sill. It suggests that the window insulation kits are not sealing well and that indoor air is still able to flow in and out from between the glass and insulation. Is there a way to make the insulation seal tighter? Another possibility is that humidity is traveling up or down through the wall and then condensing on the glass. That would be a much harder problem to solve.

No doubt others will have useful thoughts.

Yours, Larry

The kits aren't installed yet, @Larry Weingarten. The tenant is saying "to install these kits I'm going to have to dry off this condensation" which is logical

rosaliedipietro2

Thank you for your feedback.
It's baseboard heating which is underneath the window. So you're saying that this would not cause the droplets. It's happening in one of their bedrooms. The kitchen and bathroom have widows but not sure if the tenant opens them on cold days even just let's the cooking steam or shower steam permeate through the apartment

rosaliedipietro2

@pecmsg it's ridiculous that 72 is not hot enough. But unfortunately, many tenants want to walk around their apartment in shorts and an t shirt when it's 23 degrees outside. I've even told them to dress in layers during the winter. They interpret it as me being cheap (again, 72 degrees). In my own home I have forced air, which is the worst as far as I'm concerned. I don't go past 72 and if it's still a little chilly, I put on a robe and socks.

If the tenant paid for their own heat, they'd be walking around with their coats on to avoid a high heating bill lol

jesmed1

If it's happening in a bedroom, ask them if they have a humidifier running in the bedroom. The excess moisture produced by the humidifier will condense on the cold window panes and produce the droplets. My upstairs neighbor has a humidifer running in her bedroom, and when I walk outside I can see the condensation on the insides of her windows and storm windows.

IF (big IF) your tenant installs the Frost Window Insulation kits properly and makes a good seal all the way around, the humid air inside the apartment won't be able to reach the cold window panes and condense, so that mostly solves the problem. And if there is a small amount of air leakage past the window seals to the outside, which there usually is, any small amount of water vapor that does migrate past the Frost Window plastic will eventually find its way to the great outdoors.

So the key is to seal the Frost Window plastic very well so that the warm humid air inside the apartment can't reach the cold window panes. Some moisture will be trapped initially in the gap between the plastic film and the window, but it should dissipate in a day or two.

ethicalpaul

Now that I think about it, why are you relying on these insane tenants to properly install these kits?

rosaliedipietro2

@ethicalpaul I shouldn't provide anything because I provide enough heat...way above the heat mandated by the City of NY.

Tenants have no common sense and feel that if heat is included in the rent, that it should be 80 degrees in the apartment all winter long. They want to walk around with their shorts and a t shirt....no realistic! If they had to pay for the heat, they would walk around their apartment with their coats on...lol!

These particular tenants also disregarded my recommendation to re-arrange the furniture so that the baseboards are not blocked. They insist that it's not why the rooms are not warm enough...imagine?. I even sent them a video last year from This Old House to explain how baseboard heat works.

They are good tenants and I am a good landlord but sometimes a tenants expections are unreasonable.

I'm not paying to have someone put plastic on the windows.....I did however pay for the kits.

ethicalpaul

Sorry, I thought you were interested in solving the problem. My mistake.

the fact that there is condensation on the sill suggests that there are cold surfaces. These are probably uncomfortable regardless of what the thermostat reads. Does each tenant have their own thermostat that actually controls their apartment? 

Tenants, insane or not, don’t like to contact the landlord (ok some do). When they do, there could actually be a problem there.

lobuc

Can't be that cold if it's not turning to ice yet. Get a reading on the humidity and try to keep it under 40%. Some smart stats will give that info. Your heating system doesn't add humidity unless there is a leak. If there is no other means to control air quality and bath fan is plumbed properly it would be a good idea to get it on a timer or humidistat. For tenants I would suggest a tamper proof type like airtrak or Panasonic where settings are behind the cover and users can only bump it up not turn off. I understand you don't want to throw much more money at it but as a landlord you need to protect your investment.

WMno57

In unit clothes dryer? Check that it is not clogged with lint and vent to outdoors has not come apart.
Long term, consider electrifying the heat. Then tenant pays the bill. Many incentives to do this.

ChrisJ

To be fair,
Just because it's 72 at the thermostat doesn't mean it's 72 everywhere else.

The rest of the place could easily be 60-65.
Especially if there's drafts.


Even if other rooms are 70-72 drafts can make you uncomfortably cold, especially feet.