So I’ve been considering converting to an all electric house since solar is looking a lot cheaper these days and due to a combination of not having AC and finding out this week that my flexible ducts in the attic have been chewed up by rats I’m looking at installing a multi-head mini split. I’ve got few questions now that I’ve gone through the work of doing I think a mostly accurate manual J at coolcalc.com

之前我掏了进去，我在圣何塞CA，这里是顶级Calcs（计算），我有：

这1401平方英尺的我〜1 000大房间是生活，厨房和用餐（3间卧室都很小，最大的是12〜14×）。

我的房子被对半分割基本上与新建筑2×6 R-19的墙壁和然后100岁结构没有隔热壁是非常厚的（内 - >出，板条，灰泥，全尺寸2×4腔，1-2“隔板墙板，更现代的木质墙板，壁板灰泥）。下方岁半的房子我也有〜7'高的地下室，我刚打完气封，增加保温到我希望与包膜会有所帮助。

起开始如何选择一个小分裂:)。所以找这个报告我只需要从我的小型分体式系统加热的〜14K BTU的？that seems awfully low for a house that had virtually no attention to air sealing (I’ve done a decent job in the attic and the remodel had all the top plate and bottom plate penetrations spray foamed) and half the walls insulated – attic has r-30 and crawl-space (about half of my floor square footage) r-19. If this is the case, laughably the HVAC contractor installed an 80K BTU 96% AFUE furnace (Goodman Model: GMSS960804CNAA) in the attic with insulated flexible duct, and since starting to learn more about all of this late last year I’ve had a feeling that I’ve been oversized since my furnace always seems to run in short bursts. Now, only needing a 20K mini split would be great news (and I guess is close to a rule of thumb I’ve seen of ~21K BTU for ~1400 sq ft?) since I was expecting something closer to 30K or 36K BTU, but I wanted to double check that my numbers seem reasonable?

此外，我最初在大房间里放了一个头，在两个最大的卧室里有三个房间的calcs:
GreatRoom:

卧室1(1.5外墙，r-19):

BedRoom2（1个外墙，没有绝缘）：

然而，我在其他地方读过Dana的评论，头在更小的房间没有意义，因为你结束了短周期和失去效率。
此处未列出的是我有两个外部绝缘的墙壁，但在很大程度上受到了一棵橡树是一种常绿阴影微小〜9×11的卧室。我也没有列出地下室我只是绝缘，因为它只有在冬天寒冷的获取和几乎没有得到在夏季超过80个。我的主要问题是：
1）难道一个多头配置工作？
2)大房间(50 '长x ~12 '宽)里只有一个人，我该担心吗?
3）我应该关心的是小房间永不舒服，因为它是非绝缘和泄漏？
4)从表面上看，我的数字还算准确吗?
5）还有什么我俯瞰？

另外，作为一个侧面说明，如果它很重要，我打算做安装自己，然后雇人疏散，泄漏测试和充电系统，希望这似乎并不疯狂。我大部分时间迷失在HVAC承包商所有信仰学习如何事情应该主要做，看到安装我付了之后。