Replies

1. GBA Editor
   Martin Holladay|Mar 15, 2013 07:59am|#1

   Stephen,
   您确定加热和冷却设备是否需要得到加利福尼亚能源委员会的批准，然后才能合法安装？我觉得很难相信。

   我从来没有听说过加利福尼亚州的任何法律问题，与安装无管道板单元的安装有关。

2. 
   Stephen Houlihan|Mar 18, 2013 07:29pm|#2

   像大多数其他能源代码一样，《加州能源法典》（通常称为标题24）将建筑物与相同大小的“型号”进行比较，您需要证明它至少与模型房屋一样高。除非没有其他选择，否则几乎完全禁止电阻加热。允许进行热泵，但在介绍中说：“如果您打算使用它，则有一些很大的权衡，您必须使用CEC“批准”的单位。

   Steve

3. GBA Editor
   Martin Holladay|Mar 19, 2013 07:49am|#3

   Stephen,
   That's news to me. Do any other GBA readers have more information in this issue? Is there a published list of CEC-approved ductless miniplits?

4. Expert Member
   Dana Dorsett|Mar 19, 2013 04:55pm|#4

   IIRC在CA标题24 2008年（目前有效）的IIRC必须具有最低HSPF为7.7的最低HSPF，以在CA下在Title 24下进行供暖，而在大多数迷你片中，跨越13或更高的先知，障碍物很容易清除。除此之外，SFAIK没有安装它们的特殊认证和标签要求 - 没有“ CEC批准的设备列表”，只是最低效率规格。

   Somewhat dicier, mechanical systems may not be oversized by more than 15% for the load(s) per a Manual-J calculation, which may be impossible to meet for small-house small-load situations, even with a 3/4ton mini-split. There bits in the code for HVAC systems regarding ducts that don't apply with mini-split, nor does the code sufficiently address the fact that most high efficiency mini-splits are fully modulating systems with more than 3:1 turn down, and will actually run at somewhat higher average efficiency when oversized for the peak loads by about 25%.

   Then there's the refrigerant charge inspection verication rules that can't always be strictly complied with. Mini-split issues are currently under active investigation for purposes of updating the CEC for 2013 (which becomes effective January 1 2014) since much of the verbiage in current code presumes ducted split systems, with refrigerant charge verification methods commonly used in split systems that simply can't be followed in all ductless cases due to real structural differences eg:

   http://www.energy.ca.gov/title24/2013standards/prerulemaking/documents/current/Reports/Residential/HVAC/20110927Temple_MiniSplit_Investigation_acptchng.pdf

   And see section on page 51 (.pdf pagination) here:

   http://www.energy.ca.gov/title24/2013standards/rulemaking/documents/final_rulemaking_documents/23_march_13_hearing_13_hearing_residential.pdf

   But SFAIK that has never stopped mini-splits from being installed in CA, as long as they meet the 7.7HSPF/SEER13 minimums, and are often a listed feature in deep energy retrofits presented as exemplary projects, eg:

   https://www.smud.org/en/residential/save-energy/success-stories/documents/Case-Study-Jean-Ave.pdf

   Title 24 2008 in fact DID make accommodating specifications for PTHP/PTAC units, but for somehow mini-splits escaped the regulatory radar when that was being drafted. See:

   http://www.energy.ca.gov/2008publications/CEC-400-2008-016/rev1_chapters/RCM_Chapter_4_HVAC.pdf

   Bottom line, aside from a potential oversizing specification issue for such a tiny/low-load space, almost ALL mini-splits would exceed the basic raw efficiency requirements under the CEC with margin. There is no special certification or labeling step required for approval- just published & verifiable HSPF and SEER numbers that meet the spec. With literally hundreds of mini-split installers in the state, you'd probably have to go way out of your way to find a mini-split for sale in CA that wouldn't pass muster with the CEC.

5. GBA Editor
   Martin Holladay|Mar 20, 2013 09:07am|#5

   达娜，
   Thanks very much for the helpful information.