46 CFR §154.178
The heating system for transverse and longitudinal contiguous hull structure must:
- (a)Be shown by a heat load calculation to have the heating capacity to meet § 154.174(b)(2) or § 154.176(b)(2);
- (b)Have stand-by heating to provide 100% of the required heat load and distribution determined under paragraph (a); and
- (c)Meet Parts 52, 53, and 54 of this chapter.