SEER 13 or 17?
Hello,
I am renovating a 1918 home in Rhode Island. When finished the wall insulation will be about 50% closed foam, the rest blown in cellulose that has not settled much, the roof will be closed cell, I am using blue skin, 1.5 inches of rockwool, and thermalbuck as exterior shielding and extra insulation. All new double pane energy star compliant windows.
My question relates to how much air conditioning benefit I would gain from going to a seer 17 dual speed compressor over seer 13 single speed. I know that the 13 will cool the house easily, but will it run long enough to dehumidify, zone 5A temps and mid to high humidity, and filter the air? In the total cost of the project the upgrade is minor if the benefits are there. Any help would be appreciated.
GBA Detail Library
由气候和房屋部分组织的一千个建筑细节的集合
答复
在相同的交流尺寸SEER下，13个单元倾向于比SEER 17单元更好地处理湿度，但差异并不大。到目前为止，最大的因素是为明智的负载正确尺寸。如果SEER 17 2速度的尺寸适合其高速载荷，则可能会处理湿度或比SEER 13单速更好。但是，如果没有负载号和型号，就无法挖掘它。如果超过2倍或更多，则可能是他们俩都在湿度上做得很好。
I'm curious- why 50% closed cell foam?
Thanks. The house had cellulose blown in a while ago, but I am adding dormers and moving walls around. Some of the plaster walls have not survived construction.
用指定的细节级别回答这个问题。至少必须提出两种特定的交流模型并提供提交表，然后至少可以给出一些“笔和纸”估计。我还要提到，比较SEER数字可能没有那么有用。这些数字本质上是EER评级的加权平均值，它们不必考虑您的气候区域/房屋在特定的室外空气温度上花费的时间的比例。我会使用weatherspark.com之类的东西来查找一分钟，中间，最大的户外空气温度在您的城市，并尝试在这些温度下查看这两个单元的既定性能，这可能会给您带来相对的感觉性能改进。
It’s not so much the amount of insulation you have but rather which climate zone you are in that primarily determines the benefit of upgrading to a higher SEER unit. More insulation generally means you can use a smaller unit regardless of if it’s SEER 13 or 17. Climate zone gives an idea of how much runtime the unit is likely to have. You then can make a cost/benefit decision about the upgrade to see if the energy savings over the life of the unit is worth the increase in cost.
我的猜测是，在您的气候区域，这可能不值得升级，但是很难肯定地说，也不知道您的电价和单位吨位。
Bill
Go with the unit with the lowest Sensible Heat Ratio (SHR). Too often the way that manufacturers get to higher SEER is at the expense of latent load management.
Peter
If this were Georgia rather than Rhode Island that would be perfect advice.
它很潮湿，但在RI中却没有那么潮湿，新英格兰的潜在负载并不难控制，在拥有明智的负载的房屋中（即使在升级后也可能是这种情况，也可能是这种情况。）RI简单地对其进行右尺寸，以实现明智的负载，将对SEER 20下测试的任何设备具有足够的潜在控制。除湿的模式“虽然在粘性几周内。）
Of course a crummy duct design or implementation can easily defeat even the most-optimized SHR.
Thanks Dana -
但是，当它确实在RI中潮湿时，不是解决该加载密钥吗？如果我不得不选择设备来满足“峰值”负载条件，我是否会这样做来满足明智的和潜在的负载，而不是偏爱一个或另一个？
Peter
The sensible heat ratio of any SEER 13-17 equipment is adequate for RI levels of humidity as long as it isn't ridiculously oversized the way 7 out of 10 air conditioners are in that area seem to be. At 2-3x oversizing the SHR hardly matters since the duty cycle is so low. Unless the sensible load is EXACTLY at the max capacity of the equipment at ~85F (typical RI 1% outside design temp) the next quarter to half-ton step larger is more than enough to manage the latent load. Even during the most tropical week in RI the outdoor dew points are below 65F about half the time or more:
https://weatherspark.com/m/26142/8/Average-Weather-in-August-in-Cranston-Rhode-Island-United-States#Sections-Humidity
https://weatherspark.com/m/26159/8/Average-Weather-in-August-in-Newport-Rhode-Island-United-States#Sections-Humidity
Unless for health reasons you absolutely need to keep the indoor RH 45% or less, the SHR of 13-17 SEER equipment just isn't going to matter in RI.
相比之下，乔治亚州沿海地区的室外露点高于70 f，超过80％以上的时间：
https://weatherspark.com/m/17828/8/averaice-weather-weather-in-august-in-savannah-georgia-georgia-united-states#sections #sections-humity
THAT is the sort of latent load where SHR specs on 1-2 speed central air matters.
在RI中，仅保留运行时间很长的时间就足以满足Seer 20的任何内容。但是，它与大多数Seer 25-33调节迷你切片都无法使用 - 它们通常具有非常不利的SHR，并且不够清除尽管几乎连续运行时间，但在最麻烦的日子里湿度。但这就是干/除湿模式的用途。