RH too high, fresh air too low, how can I stop my windows from sweating?
I built my house without considering that I could possibly build a “too-tight” envelope. I guess I just figured that some fresh air would find it’s way inside. I have Pella Architect Series Aluminum Clad wood windows and three to four times a day I have to wipe down the glass, meeting rails, bottom rails and sills. I would say that these windows are collecting ounces of water in the form of condensation. This happens in every room in the house. I have sufficient cfm exhaust fans in the kitchen and bathroom, but I have no fresh air intake. The HVAC system is a Carrier Infinity system, but I have not yet bought the Infinity Thermostat…I have a single stage Honeywell programmable thermostat. No Infinity controller, means I do not have control over the relative humidity of the indoor conditioned air. I am seriously considering getting the controller…but, I am unconvinced that this is the answer to my problem. I have recently kept a small awning window on the first floor cracked open a couple of inches, and periodically crack open windows on the second floor. I also run the vent fans for thirty minutes at a time several times a day. This helps marginally with the humidity issues, but not entirely. My thermostat is set to 71 degrees. Oh, and I have R-13 and/or R-19 in my 2×4 or 2×6 perimeter walls, R-30 in an un-vented 2×12 warm roof, with 1.5″ polyiso above. I used gap-n-crack and window/door foam by the case. Is there enough information here for someone to give me some solutions? Please help. I am worried that I am going to have rotting windows by the end of winter.
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Replies
Roy,
Oops. You forgot to install a mechanical ventilation system.
Every house needs one, so you'll have to do some retrofit work. If you don't know what type of ventilation system to install, I recommend that your read the following article:设计ing a Good Ventilation System。
FIND THE SOURCE FIRST
当然，马丁正按照通风要求。
If you have control over occupant generated moisture, you might want to consider the possibility that the moisture is emanating from your basement or crawl-space, if you have one. If that is the case, sealing these surfaces would go a long way toward decreasing the RH in your home. It has to come from somewhere. Always deal with moisture at the source. you may have ground water issues i.e. gutters, downspouts, grading, etc... as the source.
When we perform energy retrofits, we often air-seal and insulate. If there are basement or crawl-space moisture issues, they have to be dealt with first. We also address bath and kitchen exhaust at the same time.
I was in a 80 year old home this morning and there was condensation on ever window in the house. It was gutted and remodeled less than a year ago. When I went into the basement (dirt floor with active bulk water infiltration) it was obvious that it was the source of the moisture. The basement was very "connected" to the rest of the home with no thermal or air pressure boundary. We need to stop the bulk water infiltration, seal the floor and walls, establish the thermal and air pressure boundaries and hopefully will have taken one giant step towards solving the condensation problems.
希望我有帮助！
需要仔细检查的其他事情是确保HVAC和热水器正确排出其冷凝水，而HVAC系统整个房屋加湿器（如果有的话）并没有无意间添加水分。
Roy,
马丁是对的。由于这是一栋新房子，因此您不太可能有一个主要的不受控制的水源，例如湿地下室或爬网空间。一个典型的四口之家每天从正常的生活活动开始，每天将4-5加仑的水放入室内环境中。该水需要排出。
当您在这些房间产生水分时经营厨房和浴风扇时，其中一些会发生，当您更频繁地运行这些风扇时，您会发现边缘改善。您需要的是将可编程计时器放在每个浴室的排气风扇上，并将其设置为0.25每24小时的房屋更换。
If you don't want to pay for the heating cost of air exchange in the winter, then you need to consider a heat recovery ventilator.
不仅是窗户最终会腐烂的，而且是墙壁和屋顶内的所有东西。
比评论更多的问题...但是窗户可能有问题吗？
I mean the amount of condensation described either means the humidity is way way higher than a normal range (considering there are operating bath and kitchen fans) or the temperature on the surface of the windows is much cooler than it should be.
As Robert eludes to, it seems like there are more serious moisture issues than just poor ventilation.
Roy,
I pity the poor window reps. When this problem happens, many people blame the windows, and the rep has to come out and make a site visit. It's almost never the fault of the windows, however, especially in a new home.
I assume these new Pella windows are double-glazed. They may even be low-e, although that's just a guess. If they are new, they're probably fine.
This sounds like a house with normal construction moisture and no mechanical ventilation system.
More info on the construction details would be useful. When was the house built, when was it completed, is it slab on grade or does it have a concrete basement, any interior poly sheeting on the walls, what type of siding and WRB, what is the square footage and how high are the ceilings, and yeah... where are you and what's the climate?
Also, this caught my attention:
Actually, I said it WAS almost certainly because of inadequate ventilation.
Either that, or there's a humidifier running that shouldn't be.
Sorry Robert, I was referring to your first post -"Find the source first"
Thanks to everyone for their insights and answers. I am aware that I need a mechanical ventilation system, but I am unsure whether I can simply run a 4" duct from a fresh air vent in the basement, directly into the return duct on the HVAC...or if I have to install an entirely new and substantial HRV/ERV system throughout the entire house?
我应该为您的房屋建造填写，以更好地理解问题。这是一座100+ YO，1000平方英尺，双Wythe Brick Party墙，Double Wythe Brick立面划船房屋，相邻的建筑物被占据。我保留了派对墙，立面，然后卸下了其他所有东西。所有新的地板和屋顶托梁，2x4内部框架，建筑物后部有300平方英尺的2层。（1000SF总数，不包括未完成的混凝土板基底。）8'x16'添加由XPS绝缘的CMU基础墙壁组成，2x6木材框架，Dow sis Sheahing，Certainteed水泥板板上的0.5英寸腔雨屏幕，R-19 Batt，在混凝土板爬行空间上，直接进入全高原始地下室。排屋的现有基础墙是瓦砾，折磨和防潮的。尽管有适当的底板湿度屏障，但从地面和外部有大量的水分浸润。我现在坚信我需要一个脱水剂来地下室和某种类型的机械通气...但是我必须在多大程度上走？
Turn off the water to the dehumidifier in your Carrier HVAC system. If it is on and out of control then this is your problem. If your home is tight you should never turn it on.
如果您有很多植物，则应该放弃它们，直到控制水分为止。
Run bath fans long after bath use.
Stop boiling water if that is a nightly occurance.
You have way too much moisture right now. My best guess is one of the above is out of control. I never saw new construction cause as much moisture as you describe but there will be quite a bit during drywall taping and painting and right after.
Roy,
感谢您的澄清。当您从“我建造我的房子”开始时，它似乎是新建筑，而不是它的翻新工程。这有很大的不同。
除湿机是解决方案，但是如果系统中有加湿器，则可能是问题。因此，可能会潮湿的地下室，但不要将除湿机放在那里，直到您确定这是来源。用湿度计检查。并确保您的空气密封地下室，以防止其空气被绘制到房屋中。
Whatever ventilation system you choose, it should meet the current ASHRAE 62.2 requirements of 15 cfm per person.
Roy,
You wrote, "I am unsure whether I can simply run a 4" duct from a fresh air vent in the basement, directly into the return duct on the HVAC...or if I have to install an entirely new and substantial HRV/ERV system throughout the entire house."
I urge you to read设计ing a Good Ventilation System。您的许多问题在那里得到了回答。
Your proposal -- "run a 4-in. duct from a fresh air vent in the basement, directly into the return duct on the HVAC" -- describes one of three steps required to install a central-fan-integrated supply ventilation system. (It's possible, however, that your home needs a 6-in. instead of a 4-in. duct.) The other two steps which you forgot to describe are:
- 被动空气管需要电动阻尼器，并且
-- The motorized damper and the air handler fan need to be controlled by an AirCycler control.
More information on these systems can be found onthe AirCycler Web site。
马丁，请在上面编辑我的帖子，以说加湿器。我荒谬的AutospellChanger再次将我的帖子屋顶了起来。谢谢！
AJ,
If you provide your e-mail address when you log in, you should be able to edit your own posts.
Silicon is taking over ! ... now I wrote goofed and instead posted roofed! geesh...(now I caught the rascal wanting geese, ha ha)
Yes yes... Martin... some of my devices sign me in verified some don't... I let the tech win some battles... lol
You wrote:
“尽管有适当的底板湿度屏障，但地下室是没有加热的，很有可能会从地面和外部显着渗透水分。我现在坚信我需要一个用于地下室和某种机械通气的de-umidifier ...但是我必须在多大程度上去？”
我写了上面的帖子“查找来源”。清楚地识别高RH的来源或来源是值得的时间和精力。消除或减少源中过量的水蒸气将使除湿机，ERV或HRC等机械辅助设备更容易实施。
正如罗伯特·里弗森（Robert Riversong）所指出的那样，获得湿度计并测量地下湿度。将一块平方英尺的透明塑料胶带到地下室和墙壁上，以查看是否形成凝结。如果它在塑料下形成，则水分来自平板。使用水分表测量地板和墙壁的水分含量。
如果您不拥有这些工具，那么良好的能源审核员，房屋检查员或水渗透专家可以帮助您进行诊断。
如果您发现地下室砌体是大量水分的来源，则可以考虑密封那些砌体表面。如果这有助于地下室砌体的水分水平，您可能还需要彻底评估屋顶水管理。
也许把几hygro-thermometer的差异rent points throughout your home would also help guide you to the source. They are inexpensive, under $15. In my own home I have three. Before I distributed them I place them side-by-side and calibrated.
In a perfect world, you would find the source, introduce solutions to mitigate or eliminate the moisture, and never need a dehumidifier.
祝您好运
再次感谢所有回答我沮丧的信息的人。马丁，我感谢设计良好通风系统的链接。我将在未来几天研究我的最佳选择。但是只有一个解决方案...我需要HVAC中的V。再次感谢。
如果您决定为除湿机弹簧，我建议一个能量明星自弃冻单元。我已经看到几个变成了60F范围内无用的冰可。